Plants

73 pages, 11334 KiB

Open AccessEditor’s ChoiceArticle

The Plant Communities of the Class Isoëto-Nanojuncetea in Sicily

by Salvatore Brullo, Cristian Brullo, Saverio Sciandrello, Gianmarco Tavilla, Salvatore Cambria, Valeria Tomaselli, Vincenzo Ilardi, Gianpietro Giusso del Galdo and Pietro Minissale

Plants 2022, 11(9), 1214; https://doi.org/10.3390/plants11091214 - 29 Apr 2022

Cited by 11 | Viewed by 2845

Abstract

A syntaxonomical revision of the Isoëto-Nanojuncetea class for the Sicilian territory is provided. This syntaxon gathers the ephemeral herbaceous hygrophilous plant communities linked to periodically submerged soils, widely distributed in the European, circum-Mediterranean and Macaronesian territories. Within this class, two orders are recognized, [...] Read more.

A syntaxonomical revision of the Isoëto-Nanojuncetea class for the Sicilian territory is provided. This syntaxon gathers the ephemeral herbaceous hygrophilous plant communities linked to periodically submerged soils, widely distributed in the European, circum-Mediterranean and Macaronesian territories. Within this class, two orders are recognized, lsoëtetalia, with a prevalently Mediterranean distribution, and Nanocyperetalia chiefly occurring in the central-European and Atlantic territories, with scattered and marginal occurrence in the Mediterranean area. The order Isoëtetalia in Sicily is represented by four alliances, i.e., Isoëtion, Preslion cervinae, Cicendio-Solenopsion laurentiae and Agrostion salmanticae, while within Nanocyperetalia three alliances can be recognized, namely Nanocyperion, Verbenion supinae and Lythrion tribracteati. Overall, 32 plant communities are recognized, 11 of which are described for the first time. Each higher rank syntaxa and related associations are examined from a nomenclatural, floristic, ecological and chorological point of view. In particular, the associations were processed using cluster analysis in order to highlight the correlations between them. Regarding the floristic aspects, a checklist of the species occurring in the phytosociological relevés is provided, as well as a new combination concerning Solenopsis gasparrinii, a critical species of the Sicilian flora, is proposed. Full article

(This article belongs to the Section Plant Ecology)

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15 pages, 5007 KiB

Open AccessEditor’s ChoiceArticle

Characteristics of Sunburn Browning Fruit and Rootstock-Dependent Damage-Free Yield of Ambrosia™ Apple after Sustained Summer Heat Events

by Hao Xu, Yoichiro Watanabe, Danielle Ediger, Xiaotang Yang and Davis Iritani

Plants 2022, 11(9), 1201; https://doi.org/10.3390/plants11091201 - 29 Apr 2022

Cited by 7 | Viewed by 2857

Abstract

The 2021 summer heat waves experienced in the Pacific Northwest led to considerable fruit damage in many apple production zones. Sunburn browning (SB) was a particularly evident symptom. To understand the mechanism underlying the damage and to facilitate the early assessment of compromised [...] Read more.

The 2021 summer heat waves experienced in the Pacific Northwest led to considerable fruit damage in many apple production zones. Sunburn browning (SB) was a particularly evident symptom. To understand the mechanism underlying the damage and to facilitate the early assessment of compromised fruit quality, we conducted a study on external characteristics and internal quality attributes of SB ‘Ambrosia’ apple (Malus domestica var. Ambrosia) and evaluated the fruit loss on five rootstocks. The cell integrity of the epidermal and hypodermal layers of fruit skins in the SB patch was compromised. Specifically, the number of chloroplasts and anthocyanin decreased in damaged cells, while autofluorescent stress-related compounds accumulated in dead cells. Consequently, the affected sun-exposed skin demonstrated a significant increase in differential absorbance between 670 nm and 720 nm, measured using a handheld apple DA meter, highlighting the potential of using this method as a non-destructive early indicator for sunburn damage. Sunburn browning eventually led to lower fruit weight, an increase in average dry matter content, soluble solids content, acidity, deteriorated weight retention, quicker loss of firmness, and accelerated ethylene emission during ripening. Significant inconsistency was found between the sun-exposed and shaded sides in SB apples regarding dry matter content, firmness, and tissue water potential, which implied preharvest water deficit in damaged tissues and the risk of quicker decline of postharvest quality. Geneva 935 (G.935), a large-dwarfing rootstock with more vigor and higher water transport capacity, led to a lower ratio of heat-damaged fruits and a higher yield of disorder-free fruits, suggesting rootstock selection as a long-term horticultural measure to mitigate summer heat stress. Full article

(This article belongs to the Special Issue Responses of Plants to Environmental Stresses Volume II)

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18 pages, 761 KiB

Open AccessEditor’s ChoiceReview

Environmental Behaviors of Bacillus thuringiensis (Bt) Insecticidal Proteins and Their Effects on Microbial Ecology

by Yujie Li, Cui Wang, Lei Ge, Cong Hu, Guogan Wu, Yu Sun, Lili Song, Xiao Wu, Aihu Pan, Qinqing Xu, Jialiang Shi, Jingang Liang and Peng Li

Plants 2022, 11(9), 1212; https://doi.org/10.3390/plants11091212 - 29 Apr 2022

Cited by 17 | Viewed by 7420

Abstract

Bt proteins are crystal proteins produced by Bacillus thuringiensis (Bt) in the early stage of spore formation that exhibit highly specific insecticidal activities. The application of Bt proteins primarily includes Bt transgenic plants and Bt biopesticides. Transgenic crops with insect resistance [...] Read more.

Bt proteins are crystal proteins produced by Bacillus thuringiensis (Bt) in the early stage of spore formation that exhibit highly specific insecticidal activities. The application of Bt proteins primarily includes Bt transgenic plants and Bt biopesticides. Transgenic crops with insect resistance (via Bt)/herbicide tolerance comprise the largest global area of agricultural planting. After artificial modification, Bt insecticidal proteins expressed from Bt can be released into soils through root exudates, pollen, and plant residues. In addition, the construction of Bt recombinant engineered strains through genetic engineering has become a major focus of Bt biopesticides, and the expressed Bt proteins will also remain in soil environments. Bt proteins expressed and released by Bt transgenic plants and Bt recombinant strains are structurally and functionally quite different from Bt prototoxins naturally expressed by B. thuringiensis in soils. The former can thus be regarded as an environmentally exogenous substance with insecticidal toxicity that may have potential ecological risks. Consequently, biosafety evaluations must be conducted before field tests and production of Bt plants or recombinant strains. This review summarizes the adsorption, retention, and degradation behavior of Bt insecticidal proteins in soils, in addition to their impacts on soil physical and chemical properties along with soil microbial diversity. The review provides a scientific framework for evaluating the environmental biosafety of Bt transgenic plants, Bt transgenic microorganisms, and their expression products. In addition, prospective research targets, research methods, and evaluation methods are highlighted based on current research of Bt proteins. Full article

(This article belongs to the Special Issue Biosafety and Ecological Assessment of Genetically Engineered and Edited Crops)

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19 pages, 2406 KiB

Open AccessEditor’s ChoiceReview

History of Herbicide-Resistant Traits in Cotton in the U.S. and the Importance of Integrated Weed Management for Technology Stewardship

by Rohith Vulchi, Muthukumar Bagavathiannan and Scott A. Nolte

Plants 2022, 11(9), 1189; https://doi.org/10.3390/plants11091189 - 28 Apr 2022

Cited by 8 | Viewed by 3599

Abstract

This paper reviews the history of herbicide-resistant (HR) traits in U.S. cotton since the beginning, highlighting the shortcomings of each trait over time that has led to the development of their successor and emphasizing the importance of integrated weed management (IWM) going forward [...] Read more.

This paper reviews the history of herbicide-resistant (HR) traits in U.S. cotton since the beginning, highlighting the shortcomings of each trait over time that has led to the development of their successor and emphasizing the importance of integrated weed management (IWM) going forward to ensure their long-term sustainability. Introduction of glyphosate-resistant cropping systems has allowed for expansion of no-till systems more reliant on herbicides, favored less diverse crop rotations, and heavily relied on a single herbicide mode of action (MOA). With repeated applications of glyphosate over the years, biotypes of glyphosate-resistant (GR) A. palmeri and other weeds became economically damaging pests in cotton production systems throughout the U.S. Moreover, the reported cases of weeds resistant to different MOA across various parts of the United States has increased. The dicamba- (XtendFlex^®) and 2,4-D-resistant (Enlist^®) cotton traits (with stacks of glyphosate and glufosinate resistance) were introduced and have been highly adopted in the U.S. to manage HR weeds. Given the current rate of novel herbicide MOA discovery and increase in new HR weed cases, the future of sustainable weed management relies on an integrated approach that includes non-herbicidal methods with herbicides to ensure long-term success. Full article

(This article belongs to the Topic Integrated Pest Management of Crops)

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18 pages, 5862 KiB

Open AccessEditor’s ChoiceArticle

Use of Biochar to Improve the Sustainable Crop Production of Cauliflower (Brassica oleracea L.)

by Daniela Losacco, Marina Tumolo, Pietro Cotugno, Natalia Leone, Carmine Massarelli, Stefano Convertini, Angelo Tursi, Vito Felice Uricchio and Valeria Ancona

Plants 2022, 11(9), 1182; https://doi.org/10.3390/plants11091182 - 27 Apr 2022

Cited by 11 | Viewed by 3136

Abstract

In agriculture, biochar (B) application has been suggested as a green technology to reduce nitrate pollution from agricultural origins and improve crop yield. The agronomic impact of B use on soil has been extensively studied, while knowledge of its possible effects on horticultural [...] Read more.

In agriculture, biochar (B) application has been suggested as a green technology to reduce nitrate pollution from agricultural origins and improve crop yield. The agronomic impact of B use on soil has been extensively studied, while knowledge of its possible effects on horticultural cultivation is still scarce. A greenhouse experiment was conducted to evaluate the effect of using biochar in soils treated with two different rates of nitrogen fertilizers on soil properties and nitrogen (N) leachate. This study also investigated the vegetative parameters during the crop growing season of Brassica oleracea L. var. botrytis. Soil mesocosms were set up to test the following treatments: untreated/control (C); normal dose of N fertilizer (130 kg N ha⁻¹) (ND); ND+B; high dose of N fertilizer (260 kg N ha⁻¹) (HD); and HD+B. Principal component analysis and cluster analysis were exploited to assess biochar’s ability to reduce nitrate leaching and enhance soil–vegetative properties. Biochar addition affected the soil chemical properties of the fertilized microcosms (ND and HD). Biochar increased the

N H_{4}^{+}

content in HD soil and the

N O_{3}^{-}

content in ND soil by 26 mg/L and 48.76 mg/L, respectively. The results showed that biochar application increased the marketable cauliflower yield. In ND+B and HD+B, the curd weight was 880.68 kg and 1097.60 kg, respectively. In addition, a small number of nitrogenous compounds in the leachate were quantified in experimental lines with the biochar. Therefore, biochar use improves the marketable yield of horticulture, mitigating the negative impacts associated with the mass use of N fertilizers in agriculture. Full article

(This article belongs to the Special Issue Plant Nutrition Volume II)

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15 pages, 1828 KiB

Open AccessEditor’s ChoiceArticle

Stand-Alone or Combinatorial Effects of Grafting and Microbial and Non-Microbial Derived Compounds on Vigour, Yield and Nutritive and Functional Quality of Greenhouse Eggplant

by Leo Sabatino, Beppe Benedetto Consentino, Georgia Ntatsi, Salvatore La Bella, Sara Baldassano and Youssef Rouphael

Plants 2022, 11(9), 1175; https://doi.org/10.3390/plants11091175 - 27 Apr 2022

Cited by 14 | Viewed by 2167

Abstract

The current research investigated the effects of endophytic fungi such as Trichoderma atroviride (Ta) or Ascophyllum nodosum seaweed extract (An) and their combination on growth, yield, nutritive and functional features, and mineral profile of ‘Birgah’ F₁ eggplant either ungrafted, self-grafted or grafted [...] Read more.

The current research investigated the effects of endophytic fungi such as Trichoderma atroviride (Ta) or Ascophyllum nodosum seaweed extract (An) and their combination on growth, yield, nutritive and functional features, and mineral profile of ‘Birgah’ F₁ eggplant either ungrafted, self-grafted or grafted onto the Solanum torvum rootstock. Eggplant exposed to An or An+Ta had a significant increase in root collar diameter 50 days after transplanting (RCD₅₀), total yield (TY), marketable yield (MY), ascorbic acid (AA) content, Mg, Cu, and Zn concentration, and a reduction in glycoalkaloids (GLY) compared with the control. Furthermore, grafted plants had a higher TY, MY, number of marketable fruits (NMF), RCD₅₀, AA, Cu, and Zn and a lower SSC, GLY, and Mg than the ungrafted plants. The combination of grafting and An+Ta significantly improved mean weight of marketable fruits (MF), plant height 50 days after transplanting (PH₅₀), number of leaves 50 days after transplanting (NL₅₀), fruit dry matter (FDM), chlorogenic acid (ClA), proteins, and K and Fe concentration. This combination also produced fruits of high premium quality as evidenced by the higher AA and ClA concentration, the lower GLY concentration, and an overall improved mineral profile. Full article

(This article belongs to the Section Plant Development and Morphogenesis)

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32 pages, 1796 KiB

Open AccessFeature PaperEditor’s ChoiceReview

Molecular Biology, Composition and Physiological Functions of Cuticle Lipids in Fleshy Fruits

by Heriberto García-Coronado, Julio César Tafolla-Arellano, Miguel Ángel Hernández-Oñate, Alexel Jesús Burgara-Estrella, Jesús Martín Robles-Parra and Martín Ernesto Tiznado-Hernández

Plants 2022, 11(9), 1133; https://doi.org/10.3390/plants11091133 - 22 Apr 2022

Cited by 11 | Viewed by 3183

Abstract

Fleshy fruits represent a valuable resource of economic and nutritional relevance for humanity. The plant cuticle is the external lipid layer covering the nonwoody aerial organs of land plants, and it is the first contact between fruits and the environment. It has been [...] Read more.

Fleshy fruits represent a valuable resource of economic and nutritional relevance for humanity. The plant cuticle is the external lipid layer covering the nonwoody aerial organs of land plants, and it is the first contact between fruits and the environment. It has been hypothesized that the cuticle plays a role in the development, ripening, quality, resistance to pathogen attack and postharvest shelf life of fleshy fruits. The cuticle’s structure and composition change in response to the fruit’s developmental stage, fruit physiology and different postharvest treatments. This review summarizes current information on the physiology and molecular mechanism of cuticle biosynthesis and composition changes during the development, ripening and postharvest stages of fleshy fruits. A discussion and analysis of studies regarding the relationship between cuticle composition, water loss reduction and maintaining fleshy fruits’ postharvest quality are presented. An overview of the molecular mechanism of cuticle biosynthesis and efforts to elucidate it in fleshy fruits is included. Enhancing our knowledge about cuticle biosynthesis mechanisms and identifying specific transcripts, proteins and lipids related to quality traits in fleshy fruits could contribute to the design of biotechnological strategies to improve the quality and postharvest shelf life of these important fruit crops. Full article

(This article belongs to the Special Issue Lipid Genes and Biotechnology in Plants)

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20 pages, 4004 KiB

Open AccessEditor’s ChoiceArticle

Priming Treatments with Biostimulants to Cope the Short-Term Heat Stress Response: A Transcriptomic Profile Evaluation

by Giacomo Cocetta, Michela Landoni, Roberto Pilu, Carlos Repiso, José Nolasco, Marcos Alajarin, Lydia Ugena, Camila C. B. Levy, Giacomo Scatolino, Daniele Villa and Antonio Ferrante

Plants 2022, 11(9), 1130; https://doi.org/10.3390/plants11091130 - 21 Apr 2022

Cited by 11 | Viewed by 3763

Abstract

Plant stress induced by high temperature is a problem in wide areas of different regions in the world. The trend of global warming is going to enhance the effects of heat stress on crops in many cultivation areas. Heat stress impairs the stability [...] Read more.

Plant stress induced by high temperature is a problem in wide areas of different regions in the world. The trend of global warming is going to enhance the effects of heat stress on crops in many cultivation areas. Heat stress impairs the stability of cell membranes and many biological processes involving both primary and secondary metabolism. Biostimulants are innovative agronomical tools that can be used as a strategy to counteract the detrimental effect of abiotic stresses, including heat stress. In this work, two biostimulants based on Ascophyllum nodosum extracts (named Phylgreen) and based on animal L-α amino acids (named Delfan Plus) were applied as priming treatments to Arabidopsis thaliana plants subjected to heat stress exposure. Plants at the vegetative stage were treated with biostimulants 12 h before high temperature exposure, which consisted of maintaining the plants at 37 ± 1 °C for 4 h. Transcriptional profiles, physiological, and biochemical analyses were performed to understand the mode of action of the biostimulants in protecting the plants exposed to short-term heat stress. At a physiological level, chlorophyll, chlorophyll a fluorescence, phenolic index, total anthocyanins, reactive oxygen species (ROS) were measured, and significant variations were observed immediately after stress. Both biostimulants were able to reduce the oxidative damage in leaves and cell membrane. Transcriptomic data revealed that upregulated genes were 626 in Phylgreen and 365 in Delfan Plus, while downregulated genes were 295 in Phylgreen and 312 in Delfan Plus. Bioinformatic analysis showed that the biostimulants protected the plants from heat stress by activating specific heat shock proteins (HPS), antioxidant systems, and ROS scavengers. The results revealed that the biostimulants effectively induced the activation of heat stress-associated genes belonging to different transcription factors and HSP families. Among the heat shock proteins, the most important was the AtHSP17 family and in particular, those influenced by treatments were AtHPS17.4 and AtHPS17.6A, B, showing the most relevant changes. Full article

(This article belongs to the Special Issue Plant Biostimulants)

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28 pages, 1374 KiB

Open AccessEditor’s ChoiceReview

Breeding Diploid F₁ Hybrid Potatoes for Propagation from Botanical Seed (TPS): Comparisons with Theory and Other Crops

by John E. Bradshaw

Plants 2022, 11(9), 1121; https://doi.org/10.3390/plants11091121 - 21 Apr 2022

Cited by 13 | Viewed by 3669

Abstract

This paper reviews the progress and the way ahead in diploid F₁ hybrid potato breeding by comparisons with expectations from the theory of inbreeding and crossbreeding, and experiences from other diploid outbreeding crops. Diploid potatoes can be converted from an outbreeding species, [...] Read more.

This paper reviews the progress and the way ahead in diploid F₁ hybrid potato breeding by comparisons with expectations from the theory of inbreeding and crossbreeding, and experiences from other diploid outbreeding crops. Diploid potatoes can be converted from an outbreeding species, in which self-pollination is prevented by a gametophytic self-incompatibility system, into one where self-pollination is possible, either through a dominant self-incompatibility inhibitor gene (Sli) or knockout mutations in the incompatibility locus. As a result, diploid F₁ hybrid breeding can be used to produce genetically uniform potato cultivars for propagation from true potato seeds by crossing two near-homozygous inbred lines, derived from a number of generations of self-pollination despite inbreeding depression. Molecular markers can be used to detect and remove deleterious recessive mutations of large effect, including those in tight repulsion linkage. Improvements to the inbred lines can be made by introducing and stacking genes and chromosome segments of large desirable effect from wild relatives by backcrossing. Improvements in quantitative traits require a number of cycles of inbreeding and crossbreeding. Seed production can be achieved by hand pollinations. F₁ hybrid planting material can be delivered to farmers as true seeds or young plants, and mini-tubers derived from true seeds. Full article

(This article belongs to the Special Issue Diploid F1 Hybrid Breeding in Potato)

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17 pages, 1671 KiB

Open AccessEditor’s ChoiceArticle

Diazotrophic Bacteria Is an Alternative Strategy for Increasing Grain Biofortification, Yield and Zinc Use Efficiency of Maize

by Arshad Jalal, Carlos Eduardo da Silva Oliveira, Henrique Benetasse Fernandes, Fernando Shintate Galindo, Edson Cabral da Silva, Guilherme Carlos Fernandes, Thiago Assis Rodrigues Nogueira, Pedro Henrique Gomes De Carvalho, Vinícius Rodrigues Balbino, Bruno Horschut de Lima and Marcelo Carvalho Minhoto Teixeira Filho

Plants 2022, 11(9), 1125; https://doi.org/10.3390/plants11091125 - 21 Apr 2022

Cited by 12 | Viewed by 2609

Abstract

Biofortification of cereal crops with zinc and diazotrophic bacteria is a sustainable solution to nutrient deficiency and hidden hunger. The inoculation of staple grain crops such as maize is increased with reducing productivity losses while improving nutrition and use efficiency under climatic extremes [...] Read more.

Biofortification of cereal crops with zinc and diazotrophic bacteria is a sustainable solution to nutrient deficiency and hidden hunger. The inoculation of staple grain crops such as maize is increased with reducing productivity losses while improving nutrition and use efficiency under climatic extremes and weathered soils of tropical savannah. Therefore, objectives of our study were to evaluate the influence of seed inoculation with diazotrophic bacteria (No inoculation–Control, Azospirillum brasilense, Bacillus subtilis, and Pseudomonas fluorescens) together with residual effect of soil Zn (absence and presence) on growth, yield, Zn nutrition, Zn use efficiencies, and intake of maize in 2019 and 2020 cropping seasons. The inoculation of B. subtilis increased hundred grain mass and yield (14.5 and 17%), while P. fluorescens under residual Zn fertilization has improved shoot and grain Zn concentration in shoot (29.5 and 30.5%). and grain (25.5 and 26.2%), while improving Zn accumulation in shoot (33.8 and 35%) and grain (37.2 and 42%) of maize. The estimated Zn intake in maize was also increased with A. brasilense inoculation and residual Zn application. The Zn use efficiencies including Zn use efficiency, agro-physiological, and utilization efficiency was increased with B. subtilis, while applied Zn recovery was increased with A. brasilense inoculations under residual Zn fertilization. Zinc use efficiency was increased by 93.3 and 397% with inoculation of B. subtilis regardless of Zn application. Therefore, inoculation with B. subtilis and P. fluorescens along residual Zn fertilization is considered the most effective and sustainable strategy for agronomic biofortification of maize under harsh tropical conditions of Brazil. Full article

(This article belongs to the Collection Plant Nutrition Biofortification)

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19 pages, 2922 KiB

Open AccessEditor’s ChoiceArticle

Physiological and Growth Responses of Potato (Solanum Tuberosum L.) to Air Temperature and Relative Humidity under Soil Water Deficits

by Peng Zhang, Xin Yang, Kiril Manevski, Shenglan Li, Zhenhua Wei, Mathias Neumann Andersen and Fulai Liu

Plants 2022, 11(9), 1126; https://doi.org/10.3390/plants11091126 - 21 Apr 2022

Cited by 9 | Viewed by 3036

Abstract

Drought stress often occurs concurrently with heat stress, yet the interacting effect of high vapor pressure deficit (VPD) and soil drying on the physiology of potato plants remains poorly understood. This study aimed to investigate the physiological and growth responses of potatoes to [...] Read more.

Drought stress often occurs concurrently with heat stress, yet the interacting effect of high vapor pressure deficit (VPD) and soil drying on the physiology of potato plants remains poorly understood. This study aimed to investigate the physiological and growth responses of potatoes to progressive soil drying under varied VPDs. Potato plants were grown either in four separate climate-controlled greenhouse cells with different VPD levels (viz., 0.70, 1.06, 1.40, and 2.12 kPa, respectively) or under a rainout shelter in the field. The VPD of each greenhouse cell was caused by two air temperature levels (23 and 30 °C) combined with two relative humidity levels (50 and 70%), and the VPD of the field was natural conditions. Irrigation treatments were commenced three or four weeks after planting in greenhouse cells or fields, respectively. The results indicated that soil water deficits limited leaf gas exchange and shoot dry matter (DM_shoot) of plants while increasing the concentration of abscisic acid (ABA) in the leaf and xylem, as well as water use efficiency (WUE) across all VPD levels. High VPD decreased stomatal conductance (g_s) but increased transpiration rate (T_r). High VPD increased the threshold of soil water for T_r began to decrease, while the soil water threshold for g_s depended on temperature due to the varied ABA response to temperature. High VPD decreased leaf water potential, leaf area, and DM_shoot, which exacerbated the inhibition of soil drying to plant growth. Across the well-watered plants in both experiments, negative linear relationships of g_s and WUE to VPD and positive linear relations between T_r and VPD were found. The results provide some novel information for developing mechanistic models simulating crop WUE and improving irrigation scheduling in future arid climates. Full article

(This article belongs to the Special Issue Implications of Abscisic Acid in the Drought Stress Tolerance)

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12 pages, 1795 KiB

Open AccessEditor’s ChoiceReview

Cyperus (Cyperus esculentus L.): A Review of Its Compositions, Medical Efficacy, Antibacterial Activity and Allelopathic Potentials

by Shengai Zhang, Peizhi Li, Zunmiao Wei, Yan Cheng, Jiayao Liu, Yanmin Yang, Yuyan Wang and Zhongsheng Mu

Plants 2022, 11(9), 1127; https://doi.org/10.3390/plants11091127 - 21 Apr 2022

Cited by 24 | Viewed by 5036

Abstract

Cyperus (Cyperus esculentus L.) is an edible perennial grass-like plant, which propagates exclusively with underground tubers. Its tubers are rich in starch (20–30%), fat (25–35%), sugar (10–20%), protein (10–15%) and dietary fiber (8–9%). In addition, the tubers also contain alkaloids, organic acids, [...] Read more.

Cyperus (Cyperus esculentus L.) is an edible perennial grass-like plant, which propagates exclusively with underground tubers. Its tubers are rich in starch (20–30%), fat (25–35%), sugar (10–20%), protein (10–15%) and dietary fiber (8–9%). In addition, the tubers also contain alkaloids, organic acids, vitamins (C and E), steroids, terpenoids and other active components. The contents of oleic acid and linoleic acid in Cyperus oil are very high, which have important medicinal value and health-promoting properties. Most of the extracts from the tubers, stems and leaves of Cyperus have allelopathic potential and antibacterial, antioxidant and insecticidal activities. In recent years, the planting area of Cyperus has increased significantly all over the world, especially in China and some other countries. This paper presents the current status of Cyperus and the recent trend in research in this area. Published reports on its nutritional contents, active ingredients, medicinal efficacy, antibacterial activity and allelopathic potential were also reviewed. Full article

(This article belongs to the Special Issue Plant Allelopathy: Mechanisms and Applications in Regenerative Agriculture)

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14 pages, 1138 KiB

Open AccessEditor’s ChoiceArticle

Phenolic Compounds Content Evaluation of Lettuce Grown under Short-Term Preharvest Daytime or Nighttime Supplemental LEDs

by Aušra Brazaitytė, Viktorija Vaštakaitė-Kairienė, Rūta Sutulienė, Neringa Rasiukevičiūtė, Akvilė Viršilė, Jurga Miliauskienė, Kristina Laužikė, Alma Valiuškaitė, Lina Dėnė, Simona Chrapačienė, Asta Kupčinskienė and Giedrė Samuolienė

Plants 2022, 11(9), 1123; https://doi.org/10.3390/plants11091123 - 21 Apr 2022

Cited by 13 | Viewed by 2927

Abstract

The study aimed to determine the changes in phenolic compounds content in lettuce (Lactuca sativa L. cv. Little Gem) depending on the preharvest short-term daytime or nighttime supplemental light-emitting diodes (LEDs) to high-pressure sodium lamps (HPS) lighting in a greenhouse during autumn [...] Read more.

The study aimed to determine the changes in phenolic compounds content in lettuce (Lactuca sativa L. cv. Little Gem) depending on the preharvest short-term daytime or nighttime supplemental light-emitting diodes (LEDs) to high-pressure sodium lamps (HPS) lighting in a greenhouse during autumn and spring cultivation. Plants were grown in a greenhouse under HPS supplemented with 400 nm, 455 nm, 530 nm, 455 + 530 nm or 660 nm LEDs light for 4 h five days before harvest. Two experiments (EXP) were performed: EXP1—HPS, and LEDs treatment during daytime 6 PM–10 PM, and EXP2—LEDs treatment at nighttime during 10 AM–2 PM. LEDs’ photosynthetic photon flux density (PPFD) was 50 and HPS—90 ± 10 µmol m⁻² s⁻¹. The most pronounced positive effect on total phenolic compounds revealed supplemental 400 and 455 + 530 nm LEDs lighting, except its application during the daytime at spring cultivation, when all supplemental LEDs light had no impact on phenolics content variation. Supplemental 400 nm LEDs applied in the daytime increased chlorogenic acid during spring and chicoric acid during autumn cultivation. 400 nm LEDs used in nighttime enhanced chlorogenic acid accumulation and rutin during autumn. Chicoric and chlorogenic acid significantly increased under supplemental 455 + 530 nm LEDs applied at daytime in autumn and used at nighttime—in spring. Supplemental LEDs application in the nighttime resulted in higher phenolic compounds content during spring cultivation and the daytime during autumn cultivation. Full article

(This article belongs to the Special Issue The Impact of LED (Light-Emitting Diode) Spectra on Plant Growth and Quality)

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16 pages, 3095 KiB

Open AccessEditor’s ChoiceArticle

Comparative Analysis of Chloroplast Genomes of Dalbergia Species for Identification and Phylogenetic Analysis

by Hoi-Yan Wu, Kwan-Ho Wong, Bobby Lim-Ho Kong, Tin-Yan Siu, Grace Wing-Chiu But, Stacey Shun-Kei Tsang, David Tai-Wai Lau and Pang-Chui Shaw

Plants 2022, 11(9), 1109; https://doi.org/10.3390/plants11091109 - 20 Apr 2022

Cited by 10 | Viewed by 2975

Abstract

Dalbergia L.f. is a pantropical genus consisting of 269 species of trees, shrubs, and woody lianas. This genus is listed in CITES Appendices because of illegal logging and trafficking driven by the high economic value of its heartwood. Some species are also used [...] Read more.

Dalbergia L.f. is a pantropical genus consisting of 269 species of trees, shrubs, and woody lianas. This genus is listed in CITES Appendices because of illegal logging and trafficking driven by the high economic value of its heartwood. Some species are also used medicinally. Species identification of Dalbergia timber and herbs is challenging but essential for CITES implementation. Molecular methods had been developed for some timber species, mostly from Madagascar and Southeast Asia, but medicinal species in south China were usually not included in those studies. Here, we sequenced and assembled the chloroplast genomes of five Dalbergia species native to Hong Kong, four of which are medicinal plants. Our aim is to find potential genetic markers for the identification of medicinal Dalbergia species based on divergence hotspots detected in chloroplast genomes after comparative and phylogenetic analysis. Dalbergia chloroplast genomes displayed the typical quadripartite structure, with the 50 kb inversion found in most Papilionoideae lineages. Their sizes and gene content are well conserved. Phylogenetic tree of Dalbergia chloroplast genomes showed an overall topology similar to that of ITS sequences. Four divergence hotspots (trnL(UAA)-trnT(UGU), ndhG-ndhI, ycf1a and ycf1b) were identified and candidate markers for identification of several Dalbergia species were suggested. Full article

(This article belongs to the Section Plant Genetics, Genomics and Biotechnology)

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22 pages, 1050 KiB

Open AccessFeature PaperEditor’s ChoiceReview

Emerging Roles of β-Glucanases in Plant Development and Adaptative Responses

by Thomas Perrot, Markus Pauly and Vicente Ramírez

Plants 2022, 11(9), 1119; https://doi.org/10.3390/plants11091119 - 20 Apr 2022

Cited by 44 | Viewed by 5730

Abstract

Plant β-glucanases are enzymes involved in the synthesis, remodelling and turnover of cell wall components during multiple physiological processes. Based on the type of the glycoside bond they cleave, plant β-glucanases have been grouped into three categories: (i) β-1,4-glucanases degrade cellulose and other [...] Read more.

Plant β-glucanases are enzymes involved in the synthesis, remodelling and turnover of cell wall components during multiple physiological processes. Based on the type of the glycoside bond they cleave, plant β-glucanases have been grouped into three categories: (i) β-1,4-glucanases degrade cellulose and other polysaccharides containing 1,4-glycosidic bonds to remodel and disassemble the wall during cell growth. (ii) β-1,3-glucanases are responsible for the mobilization of callose, governing the symplastic trafficking through plasmodesmata. (iii) β-1,3-1,4-glucanases degrade mixed linkage glucan, a transient wall polysaccharide found in cereals, which is broken down to obtain energy during rapid seedling growth. In addition to their roles in the turnover of self-glucan structures, plant β-glucanases are crucial in regulating the outcome in symbiotic and hostile plant–microbe interactions by degrading non-self glucan structures. Plants use these enzymes to hydrolyse β-glucans found in the walls of microbes, not only by contributing to a local antimicrobial defence barrier, but also by generating signalling glucans triggering the activation of global responses. As a counterpart, microbes developed strategies to hijack plant β-glucanases to their advantage to successfully colonize plant tissues. This review outlines our current understanding on plant β-glucanases, with a particular focus on the latest advances on their roles in adaptative responses. Full article

(This article belongs to the Special Issue Plant Cell Wall Plasticity under Stress Situations)

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14 pages, 1918 KiB

Open AccessEditor’s ChoiceArticle

Grape Cultivar Features Differentiate the Grape Rhizosphere Microbiota

by Lijun Bao, Bo Sun, Yingxue Wei, Nan Xu, Shiwei Zhang, Likun Gu and Zhihui Bai

Plants 2022, 11(9), 1111; https://doi.org/10.3390/plants11091111 - 20 Apr 2022

Cited by 13 | Viewed by 3399

Abstract

Rhizosphere microflora are key determinants that contribute to plant growth and productivity, which are involved in improving the uptake of nutrients, regulation of plants’ metabolisms and activation of plants’ responses against both biotic and abiotic stresses. However, the structure and diversity of the [...] Read more.

Rhizosphere microflora are key determinants that contribute to plant growth and productivity, which are involved in improving the uptake of nutrients, regulation of plants’ metabolisms and activation of plants’ responses against both biotic and abiotic stresses. However, the structure and diversity of the grape rhizosphere microbiota remains poorly described. To gain a detailed understanding of the assembly of rhizosphere microbiota, we investigated the rhizosphere microbiota of nine grape varieties in northern China by high-throughput sequencing. We found that the richness and diversity of bacterial and fungal community networking in the root compartments were significantly influenced by the grape variety. The bacterial linear discriminant analysis showed that Pseudomonas and Rhizobium, which were considered as potential plant-growth-promoting bacteria, were more enriched in Pinot noir, and Nitrosospira was enriched in Gem. The fungal linear discriminant analysis showed that Fusarium was more enriched in Longan, Sporormiella was more enriched in Merlot, Gibberella and Pseudallescheria were more enriched in Gem and Mortierella was more abundant in Cabernet Sauvignon. The 16S rRNA functional prediction indicated that no significance differentiates among the grape varieties. Understanding the rhizosphere soil microbial diversity characteristics of different grape varieties could provide the basis for exploring microbial associations and maintaining the health of grapes. Full article

(This article belongs to the Special Issue Interaction of Plants and Endophytic Microorganisms: Molecular Aspects, Biological Functions, Community Composition, and Practical Applications)

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18 pages, 2741 KiB

Open AccessEditor’s ChoiceArticle

Metabolic Modifications in Terpenoid and Steroid Pathways Triggered by Methyl Jasmonate in Taxus × media Hairy Roots

by Katarzyna Sykłowska-Baranek, Monika Kamińska, Cezary Pączkowski, Agnieszka Pietrosiuk and Anna Szakiel

Plants 2022, 11(9), 1120; https://doi.org/10.3390/plants11091120 - 20 Apr 2022

Cited by 10 | Viewed by 2102

Abstract

The in vitro cultures of Taxus spp. were one of the first plant in vitro systems proved to exert the positive effect of elicitation with methyl jasmonate (MeJA) on the biosynthesis of specialized metabolites. The main aim of the present study is to [...] Read more.

The in vitro cultures of Taxus spp. were one of the first plant in vitro systems proved to exert the positive effect of elicitation with methyl jasmonate (MeJA) on the biosynthesis of specialized metabolites. The main aim of the present study is to examine the effect of MeJA treatment on the steroid and triterpenoid content of two genetically different hairy root lines of Taxus × media, KT and ATMA. The results revealed that the two lines differed in the total content of steroids and triterpenoids (in the ATMA root line, their amounts were lower than those in the KT line by 43% and 30%, respectively), but not in the composition of these compounds. The metabolic response to elicitation with MeJA was different: in the KT root line, the content of steroids decreased by 18%, whereas it increased by 38% in the ATMA line. Several metabolic features were common, including the characteristic changes in the ratio of sitosterol to stigmasterol content, caused by the very sharp boost in stigmasterol levels, the increase in the amount of glycoside forms of sterols, as well as in triterpenoid and total phenolic content. It is the first report on modifications of the terpenoid biosynthetic pathway in Taxus hairy root cultures triggered by MeJA, concerning steroids and triterpenoids. Full article

(This article belongs to the Special Issue Specialized Metabolites in Root cultures)

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14 pages, 1190 KiB

Open AccessEditor’s ChoiceArticle

Complex Synergistic Interactions among Volatile and Phenolic Compounds Underlie the Effectiveness of Allelopathic Residues Added to the Soil for Weed Control

by María Pardo-Muras, Carolina G. Puig and Nuria Pedrol

Plants 2022, 11(9), 1114; https://doi.org/10.3390/plants11091114 - 20 Apr 2022

Cited by 15 | Viewed by 2041

Abstract

The introduction of allelopathic cover crops for green manuring or mulching is a regular practice in Integrated Weed Management. In this context, the alternative use of the abundant phytotoxic residues of allelopathic plants from the agroecosystem, e.g., the foliage of Eucalyptus, Acacia [...] Read more.

The introduction of allelopathic cover crops for green manuring or mulching is a regular practice in Integrated Weed Management. In this context, the alternative use of the abundant phytotoxic residues of allelopathic plants from the agroecosystem, e.g., the foliage of Eucalyptus, Acacia, or Cytisus species, is promising. Previous studies identified the phytotoxic compounds potentially involved in the effectiveness of some plant residues when added to the soil for weed control. The low quantities of allelochemicals present in the tissues and the weak phytotoxicity of each of them in their natural concentrations did not explain the significant levels of weed control observed at field scale. Here, to study hypothetical synergistic interactions among the volatile (VOCs) and water-soluble compounds released to the soil matrix, complex mixtures of VOCs, phenolics, or both, mimicking the chemical profiles of Cytisus scoparius were prepared and then tested in vitro on the germination and early growth of two weeds. The effects were calibrated against the VOCs naturally emitted by the fresh plant material and aqueous extract, acting together or not, and with or without soil. The presence of the aqueous extract significantly increased the phytotoxicity of VOCs on Amaranthus retroflexus root growth compared to the volatiles emitted alone. In addition, the soil factor enhanced synergistic interactions among VOCs and water-soluble compounds, resulting in a 54% decrease in total germination and an 80% inhibition of root and shoot growth. Multi-level synergistic chemical interactions should explain the bioherbicidal effectiveness of allelopathic residues applied as a soil amendment. Full article

(This article belongs to the Special Issue Plant Extracts as Biological Protective Agents)

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28 pages, 6413 KiB

Open AccessEditor’s ChoiceReview

Chemical Structure, Sources and Role of Bioactive Flavonoids in Cancer Prevention: A Review

by Georgiana Drețcanu, Ioana Știrbu, Nicolae Leoplold, Daniel Cruceriu, Corina Danciu, Andreea Stănilă, Anca Fărcaș, Ileana Monica Borda, Cristian Iuhas and Zorița Diaconeasa

Plants 2022, 11(9), 1117; https://doi.org/10.3390/plants11091117 - 20 Apr 2022

Cited by 17 | Viewed by 3244

Abstract

There has been a major shift in the collective mindset around the world in recent decades, both in terms of food and in terms of the treatment of chronic diseases. Increasing numbers of people are choosing to prevent rather than treat, which is [...] Read more.

There has been a major shift in the collective mindset around the world in recent decades, both in terms of food and in terms of the treatment of chronic diseases. Increasing numbers of people are choosing to prevent rather than treat, which is why many consumers are choosing plant-based diets, mainly due to their bioactive compounds. A significant case of bioactive compound is flavonoids—a wide subclass of an even wider class of phytochemicals: polyphenols. Flavonoids are a broad topic of study for researchers due to their potential in the prevention and treatment of a broad range of cancers. The aim of this review is to inform/update the reader on the diversity, accessibility and importance of flavonoids as biomolecules that are essential for optimal health, focusing on the potential of these compounds in the prevention of various types of cancer. Along with conventional sources, this review presents some of the possible methods for obtaining significant amounts of flavonoids based on a slightly different approach, genetic manipulation. Full article

(This article belongs to the Special Issue Antioxidant Activity of Plant Extracts)

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25 pages, 1469 KiB

Open AccessEditor’s ChoiceReview

Abiotic Stresses in Plants and Their Markers: A Practice View of Plant Stress Responses and Programmed Cell Death Mechanisms

by Bruno Paes de Melo, Paola de Avelar Carpinetti, Otto Teixeira Fraga, Paolo Lucas Rodrigues-Silva, Vinícius Sartori Fioresi, Luiz Fernando de Camargos and Marcia Flores da Silva Ferreira

Plants 2022, 11(9), 1100; https://doi.org/10.3390/plants11091100 - 19 Apr 2022

Cited by 31 | Viewed by 10551

Abstract

Understanding how plants cope with stress and the intricate mechanisms thereby used to adapt and survive environmental imbalances comprise one of the most powerful tools for modern agriculture. Interdisciplinary studies suggest that knowledge in how plants perceive, transduce and respond to abiotic stresses [...] Read more.

Understanding how plants cope with stress and the intricate mechanisms thereby used to adapt and survive environmental imbalances comprise one of the most powerful tools for modern agriculture. Interdisciplinary studies suggest that knowledge in how plants perceive, transduce and respond to abiotic stresses are a meaningful way to design engineered crops since the manipulation of basic characteristics leads to physiological remodeling for plant adaption to different environments. Herein, we discussed the main pathways involved in stress-sensing, signal transduction and plant adaption, highlighting biochemical, physiological and genetic events involved in abiotic stress responses. Finally, we have proposed a list of practice markers for studying plant responses to multiple stresses, highlighting how plant molecular biology, phenotyping and genetic engineering interconnect for creating superior crops. Full article

(This article belongs to the Special Issue Plant Cellular Homeostasis and Reprogramming during Stress)

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15 pages, 3352 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Angelica purpurascens (Avé-Lall.) Gilli. Essential Oil Improved Brain Function via Cholinergic Modulation and Antioxidant Effects in the Scopolamine-Induced Zebrafish (Danio rerio) Model

by Razvan Stefan Boiangiu, Eyup Bagci, Gabriela Dumitru, Lucian Hritcu and Elena Todirascu-Ciornea

Plants 2022, 11(8), 1096; https://doi.org/10.3390/plants11081096 - 18 Apr 2022

Cited by 6 | Viewed by 2672

Abstract

Angelica purpurascens (Avé-Lall.) Gilli. is a medicinal plant that displays antioxidant, anticholinesterase, and neuroprotective properties. The effect of A. purpurascens essential oil (APO) on memory impairments and brain oxidative stress in zebrafish (Danio rerio) treated with scopolamine (Sco), as well as [...] Read more.

Angelica purpurascens (Avé-Lall.) Gilli. is a medicinal plant that displays antioxidant, anticholinesterase, and neuroprotective properties. The effect of A. purpurascens essential oil (APO) on memory impairments and brain oxidative stress in zebrafish (Danio rerio) treated with scopolamine (Sco), as well as the underlying mechanism involved, were investigated in this study. Exposure to Sco (100 μM) resulted in anxiety in zebrafish, as assessed by the novel tank diving test (NTT), whereas spatial memory and novelty response dysfunctions, as evidenced by the Y-maze test and novel object recognition test (NOR), were noticed. When zebrafish were given Sco and simultaneously given APO (25 and 150 μL/L, once daily for 13 days), the deficits were averted. An increase in brain antioxidant enzymes, a reduction of lipid peroxidation, and protein oxidation were linked to this impact. Furthermore, acetylcholinesterase (AChE) activity was significantly reduced in the brains of APO-treated zebrafish. The main detected components in the APO composition were β-phellandrene (33.80%), sabinene (6.80%), α-pinene (5.30%), germacrene-D (4.50%), α-phellandrene (4.20%), and p-cymene (3.80%) based on gas chromatography–mass spectrometry (GC-MS) investigations. Our findings show that APO’s beneficial effect in a zebrafish model of Sco-induced memory impairment is mediated through multiple mechanisms, including the restoration of cholinergic system function and the improvement of the brain antioxidant state. As a result, APO could be employed as a potential source of bioactive molecules with useful biological properties and medicinal uses. Full article

(This article belongs to the Special Issue Antioxidant Activity of Plant Extracts)

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16 pages, 1846 KiB

Open AccessEditor’s ChoiceReview

Transient Expression of Glycosylated SARS-CoV-2 Antigens in Nicotiana benthamiana

by Valentina Ruocco and Richard Strasser

Plants 2022, 11(8), 1093; https://doi.org/10.3390/plants11081093 - 18 Apr 2022

Cited by 12 | Viewed by 3635

Abstract

The current COVID-19 pandemic very dramatically shows that the world lacks preparedness for novel viral diseases. In addition to newly emerging viruses, many known pathogenic viruses such as influenza are constantly evolving, leading to frequent outbreaks with severe diseases and deaths. Hence, infectious [...] Read more.

The current COVID-19 pandemic very dramatically shows that the world lacks preparedness for novel viral diseases. In addition to newly emerging viruses, many known pathogenic viruses such as influenza are constantly evolving, leading to frequent outbreaks with severe diseases and deaths. Hence, infectious viruses are a recurrent burden to our daily life, and powerful strategies to stop the spread of human pathogens and disease progression are of utmost importance. Transient plant-based protein expression is a technology that allows fast and highly flexible manufacturing of recombinant viral proteins and, thus, can contribute to infectious disease detection and prevention. This review highlights recent progress in the transient production of viral glycoproteins in N. benthamiana with a focus on SARS-CoV-2-derived viral antigens. Full article

(This article belongs to the Special Issue Plant-Based Expression System)

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19 pages, 3260 KiB

Open AccessEditor’s ChoiceArticle

Improved Medicago sativa Nodulation under Stress Assisted by Variovorax sp. Endophytes

by Noris J. Flores-Duarte, Julia Pérez-Pérez, Salvadora Navarro-Torre, Enrique Mateos-Naranjo, Susana Redondo-Gómez, Eloísa Pajuelo and Ignacio D. Rodríguez-Llorente

Plants 2022, 11(8), 1091; https://doi.org/10.3390/plants11081091 - 17 Apr 2022

Cited by 18 | Viewed by 2535

Abstract

Legumes are the recommended crops to fight against soil degradation and loss of fertility because of their known positive impacts on soils. Our interest is focused on the identification of plant-growth-promoting endophytes inhabiting nodules able to enhance legume growth in poor and/or degraded [...] Read more.

Legumes are the recommended crops to fight against soil degradation and loss of fertility because of their known positive impacts on soils. Our interest is focused on the identification of plant-growth-promoting endophytes inhabiting nodules able to enhance legume growth in poor and/or degraded soils. The ability of Variovorax paradoxus S110^T and Variovorax gossypii JM-310^T to promote alfalfa growth in nutrient-poor and metal-contaminated estuarine soils was studied. Both strains behaved as nodule endophytes and improved in vitro seed germination and plant growth, as well as nodulation in co-inoculation with Ensifer medicae MA11. Variovorax ameliorated the physiological status of the plant, increased nodulation, chlorophyll and nitrogen content, and the response to stress and metal accumulation in the roots of alfalfa growing in degraded soils with moderate to high levels of contamination. The presence of plant-growth-promoting traits in Variovorax, particularly ACC deaminase activity, could be under the observed in planta effects. Although the couple V. gossypii-MA11 reported a great benefit to plant growth and nodulation, the best result was observed in plants inoculated with the combination of the three bacteria. These results suggest that Variovorax strains could be used as biofertilizers to improve the adaptation of legumes to degraded soils in soil-recovery programs. Full article

(This article belongs to the Special Issue Interaction of Plants and Endophytic Microorganisms: Molecular Aspects, Biological Functions, Community Composition, and Practical Applications)

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19 pages, 1731 KiB

Open AccessEditor’s ChoiceArticle

Genetic Characterization by SSR Markers of a Comprehensive Wine Grape Collection Conserved at Rancho de la Merced (Andalusia, Spain)

by Enrico Cretazzo, Paula Moreno Sanz, Silvia Lorenzi, Miguel Lara Benítez, Leonardo Velasco and Francesco Emanuelli

Plants 2022, 11(8), 1088; https://doi.org/10.3390/plants11081088 - 16 Apr 2022

Cited by 19 | Viewed by 2709

Abstract

The IFAPA research center “Rancho de la Merced” (Jerez, Spain) hosts one of the oldest and most diverse grapevine germplasm repositories in Europe, and is aimed at providing feasible solutions to deal with any agronomic trait by exploring its genetic variability and by [...] Read more.

The IFAPA research center “Rancho de la Merced” (Jerez, Spain) hosts one of the oldest and most diverse grapevine germplasm repositories in Europe, and is aimed at providing feasible solutions to deal with any agronomic trait by exploring its genetic variability and by means of association and Deoxyribonucleic Acid (DNA) editing studies. In this work, we focused on a wine and dual-use grapevine subcollection that consists of 930 accessions. Genetic analysis allowed to identify 521 unique genotypes. After comparing them with several databases, matches were found for 476 genetic profiles while the remaining 45 have not been previously described. Combination with clustering analysis suggested a total pool of 481 Vitis vinifera accessions that included some table cultivars. Several synonymies, homonymies and mislabeling have also been detected. Structure analysis allowed identifying six clusters according to eco-geographic cultivation areas and one additional group including non-vinifera accessions. Diversity analysis pointed out that Spanish Mediterranean varieties are genetically closer to oriental genotypes than to European varieties typical of oceanic and continental climates. The origin of Spanish varieties is discussed in depth considering our data and previous studies. Analysis of molecular variance partition confirmed a well-structured germplasm, although differentiation among groups had a much lower effect on genetic variability than differences within groups, which are strongly related to a very high heterozygosity. A core collection that covers all allele richness is proposed. It is constituted of about 13% of total accessions, and each cluster inferred by structure analysis is represented. Full article

(This article belongs to the Section Plant Genetics, Genomics and Biotechnology)

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16 pages, 2996 KiB

Open AccessEditor’s ChoiceArticle

Eucalyptus globulus and Salvia officinalis Extracts Mediated Green Synthesis of Silver Nanoparticles and Their Application as an Antioxidant and Antimicrobial Agent

by Aistė Balčiūnaitienė, Mindaugas Liaudanskas, Viktorija Puzerytė, Jonas Viškelis, Valdimaras Janulis, Pranas Viškelis, Egidijus Griškonis and Virginija Jankauskaitė

Plants 2022, 11(8), 1085; https://doi.org/10.3390/plants11081085 - 15 Apr 2022

Cited by 26 | Viewed by 3821

Abstract

Silver nanoparticles (AgNPs) biosynthesized using plant extracts as reducing and capping agents show multiple possibilities for solving various biological problems. The aim of this study was to expand the boundaries of AgNPs using a novel low toxicity and production cost phytochemical method for [...] Read more.

Silver nanoparticles (AgNPs) biosynthesized using plant extracts as reducing and capping agents show multiple possibilities for solving various biological problems. The aim of this study was to expand the boundaries of AgNPs using a novel low toxicity and production cost phytochemical method for the biosynthesis of nanoparticles from Eucalyptus globulus and Salvia officinalis aqueous leaf extracts. Biosynthesized AgNPs were characterized by various methods (ultraviolet-visible spectroscopy (UV-vis), Fourier transform infrared (FTIR) spectroscopy with horizontal attenuated total reflectance (HART), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS)). The determined antioxidative and antimicrobial activity of plant extracts was compared with the activity of the AgNPs. The UV-vis spectral analysis demonstrated the absorption peaks at 408 and 438 nm, which confirmed the synthesis of stable AgNPs from E. globulus and S. officinalis, respectively. FTIR-HART results suggested strong capping of phytochemicals on AgNPs. TEM results show mainly spherical-shaped AgNPs, whose size distribution depends on the plant leaf extract type; the smaller AgNPs were obtained with E. globulus extract (with size range of 17.5 ± 5.89 nm compared to 34.3 ± 7.76 nm from S. officinalis AgNPs). The in vitro antioxidant activity evaluated by radical scavenging assays and the reduction activity method clearly demonstrated that both the plant extracts and AgNPs showed prominent antioxidant properties. In addition, AgNPs show much stronger antimicrobial activity against broad spectrum of Gram-negative and Gram-positive bacteria strains than the plant extracts used for their synthesis. Full article

(This article belongs to the Special Issue Natural Resources of Berry and Medicinal Plants Volume II)

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14 pages, 1551 KiB

Open AccessEditor’s ChoiceArticle

A Comparative Study of Isolated Secondary Metabolites from Lichens and Their Antioxidative Properties

by Ján Elečko, Mária Vilková, Richard Frenák, Deepti Routray, Dajana Ručová, Martin Bačkor and Michal Goga

Plants 2022, 11(8), 1077; https://doi.org/10.3390/plants11081077 - 15 Apr 2022

Cited by 23 | Viewed by 2303

Abstract

Free radicals play a critical role in the chemical processes that occur in all cells. Pharmaceutical companies manufacture a variety of synthetically prepared antioxidants, but it is known that many of these can be carcinogenic. As a result, efforts are being made to [...] Read more.

Free radicals play a critical role in the chemical processes that occur in all cells. Pharmaceutical companies manufacture a variety of synthetically prepared antioxidants, but it is known that many of these can be carcinogenic. As a result, efforts are being made to find natural antioxidants that do not have these side effects. Lichens may be suitable candidates because they contain secondary metabolites with proven antioxidant properties. This could be explained by the presence of compounds with phenolic groups in lichens. The radical scavenging reaction is a chemical reaction governed by stoichiometry, and our aim is to determine the efficacy of these reactions. The aim of this study is to compare metabolite activity based on the same amount of substance involved in radical scavenging, calculated in micromoles rather than weight concentration. This provides an accurate way of comparing radical scavenging activity. We tested superoxide anion scavenging activity and free radical scavenging activity of isolated lichen secondary metabolites and their mixtures in different ratios. The following compounds were isolated and tested for antioxidant activity: gyrophoric acid (Umbilicaria hirsuta), evernic acid (Evernia prunastri), physodic acid, 3-hydroxyphysodic acid, physodalic acid and atranorin (Hypogymnia physodes), and usnic acid (as a synthetic compound). Of all the tested compounds, 3-hydroxyphysodic acid, as well as mixtures containing this metabolite, showed the strongest scavenging activity. The results also demonstrated that calculation by amount of substance leads to a new consideration of antioxidant activity. Full article

(This article belongs to the Special Issue Secondary Metabolites from Lichens and Biological Activity)

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19 pages, 5262 KiB

Open AccessEditor’s ChoiceArticle

In Vitro Study of the Biological Potential of Wastewater Obtained after the Distillation of Four Bulgarian Oil-Bearing Roses

by Yana Ilieva, Lyudmila Dimitrova, Almira Georgieva, Neli Vilhelmova-Ilieva, Maya Margaritova Zaharieva, Zlatina Kokanova-Nedialkova, Ana Dobreva, Paraskev Nedialkov, Vesselin Kussovski, Alexander D. Kroumov, Hristo Najdenski and Milka Mileva

Plants 2022, 11(8), 1073; https://doi.org/10.3390/plants11081073 - 14 Apr 2022

Cited by 7 | Viewed by 2125

Abstract

The wastewater after rose oil distillation is usually discharged into the drainage systems and it represents a serious environmental problem. While being rich in polyphenols, which have beneficial biological activity and application in the pharmaceutical industry, limited research has been carried out about [...] Read more.

The wastewater after rose oil distillation is usually discharged into the drainage systems and it represents a serious environmental problem. While being rich in polyphenols, which have beneficial biological activity and application in the pharmaceutical industry, limited research has been carried out about the biological activity of the specific wastewaters per se. Wastewaters after distillation of the four Bulgarian oil-bearing roses Rosa damascena Mill., R. alba L., R. centifolia L., and R. gallica L. exerted significant antioxidant activity and good antiherpes simplex virus type-1 (HSV-1) activity while maintaining a good toxicological safety profile (low cytotoxic effect) towards normal cell lines. More precisely, the non-tumorigenic cells were a human (HEK-293 embryonic kidney cells) and a mouse cell line (CCL-1 fibroblasts, which are recommended as a standard for cytotoxicity evaluation in Annex C of ISO 10993-5). The concentrations that achieved antioxidant and radical scavenging effects (0.04–0.92% v/v) were much lower than most of the maximum tolerated concentrations for the tissue culture cells (0.2–3.4% v/v). The wastewaters had a weak antiproliferative effect against Staphylococcus aureus. None of the wastewaters had activity against Gram-negative bacteria or a bactericidal or antifungal effect. We can conclude that these four species, which are the most preferred species worldwide for producing high-quality rose oil, have the potential to be developed as promising antioxidant and antiherpesvirus nutraceuticals. Full article

(This article belongs to the Special Issue Specialized Metabolites of Plants—Evaluation of Functional and Biological Value)

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22 pages, 4300 KiB

Open AccessEditor’s ChoiceArticle

Photoprotection Is Achieved by Photorespiration and Modification of the Leaf Incident Light, and Their Extent Is Modulated by the Stomatal Sensitivity to Water Deficit in Grapevines

by Luis Villalobos-González, Nicolás Alarcón, Roberto Bastías, Cristobal Pérez, René Sanz, Álvaro Peña-Neira and Claudio Pastenes

Plants 2022, 11(8), 1050; https://doi.org/10.3390/plants11081050 - 12 Apr 2022

Cited by 8 | Viewed by 2294

Abstract

Absorbed energy in excess of that used by photosynthesis induces photoinhibition, which is common in water deficit conditions, resulting in reductions in stomatal conductance. In grapevines, controlled water deficit is a common field practice, but little is known about the impact of a [...] Read more.

Absorbed energy in excess of that used by photosynthesis induces photoinhibition, which is common in water deficit conditions, resulting in reductions in stomatal conductance. In grapevines, controlled water deficit is a common field practice, but little is known about the impact of a given water shortage on the energy transduction processes at the leaf level in relation to contrasting stomatal sensitivities to drought. Here, we assessed the effect of a nearly similar water deficit condition on four grapevine varieties: Cabernet Sauvignon (CS) and Sauvignon Blanc (SB), which are stomatal sensitive, and Chardonnay (CH) and Carménère (CM), which are less stomatal sensitive, grown in 20 L pots outdoors. Plants were maintained to nearly 94% of field capacity (WW) and 83% field capacity (WD). We have assessed plant water status, photosynthesis (A_N), photorespiration, A_N vs. PAR, AC_i curves, photochemical (qP) and non-photochemical (qN) fluorescence quenching vs. PAR, the photoprotective effectiveness of NPQ (qPd) and light interception by leaves. Photorespiration is important under WD, but to a different extent between varieties. This is related to stomatal sensitivity, maintaining a safe proportion of PSII reaction centres in an open state. Additionally, the capacity for carboxylation is affected by WD, but to a greater extent in more sensitive varieties. As for qN, in WD it saturates at 750 μmol PAR m⁻²s⁻¹, irrespective of the variety, which coincides with PAR, from which qN photoprotective effectiveness declines, and qP is reduced to risky thresholds. Additionally, that same PAR intensity is intercepted by WD leaves from highly stomatal-sensitive varieties, likely due to a modification of the leaf angle in those plants. Pigments associated with qN, as well as chlorophylls, do not seem to be a relevant physiological target for acclimation. Full article

(This article belongs to the Special Issue Regulation of Plant Responses to Heat and Drought Stress)

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16 pages, 1820 KiB

Open AccessEditor’s ChoiceReview

Epitranscriptomics: An Additional Regulatory Layer in Plants’ Development and Stress Response

by Yasira Shoaib, Babar Usman, Hunseung Kang and Ki-Hong Jung

Plants 2022, 11(8), 1033; https://doi.org/10.3390/plants11081033 - 11 Apr 2022

Cited by 7 | Viewed by 3911

Abstract

Epitranscriptomics has added a new layer of regulatory machinery to eukaryotes, and the advancement of sequencing technology has revealed more than 170 post-transcriptional modifications in various types of RNAs, including messenger RNA (mRNA), transfer RNA (tRNA), ribosomal RNA (rRNA), and long non-coding RNA [...] Read more.

Epitranscriptomics has added a new layer of regulatory machinery to eukaryotes, and the advancement of sequencing technology has revealed more than 170 post-transcriptional modifications in various types of RNAs, including messenger RNA (mRNA), transfer RNA (tRNA), ribosomal RNA (rRNA), and long non-coding RNA (lncRNA). Among these, N6-methyladenosine (m⁶A) and N5-methylcytidine (m⁵C) are the most prevalent internal mRNA modifications. These regulate various aspects of RNA metabolism, mainly mRNA degradation and translation. Recent advances have shown that regulation of RNA fate mediated by these epitranscriptomic marks has pervasive effects on a plant’s development and responses to various biotic and abiotic stresses. Recently, it was demonstrated that the removal of human-FTO-mediated m⁶A from transcripts in transgenic rice and potatoes caused a dramatic increase in their yield, and that the m⁶A reader protein mediates stress responses in wheat and apple, indicating that regulation of m⁶A levels could be an efficient strategy for crop improvement. However, changing the overall m⁶A levels might have unpredictable effects; therefore, the identification of precise m⁶A levels at a single-base resolution is essential. In this review, we emphasize the roles of epitranscriptomic modifications in modulating molecular, physiological, and stress responses in plants, and provide an outlook on epitranscriptome engineering as a promising tool to ensure food security by editing specific m⁶A and m⁵C sites through robust genome-editing technology. Full article

(This article belongs to the Special Issue Responses of Plants to Environmental Stresses Volume II)

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14 pages, 349 KiB

Open AccessEditor’s ChoiceArticle

Assessment of Ocimum basilicum Essential Oil Anti-Insect Activity and Antimicrobial Protection in Fruit and Vegetable Quality

by Miroslava Kačániová, Lucia Galovičová, Petra Borotová, Nenad L. Vukovic, Milena Vukic, Simona Kunová, Pavel Hanus, Ladislav Bakay, Edyta Zagrobelna, Maciej Kluz and Przemysław Łukasz Kowalczewski

Plants 2022, 11(8), 1030; https://doi.org/10.3390/plants11081030 - 10 Apr 2022

Cited by 17 | Viewed by 3029

Abstract

Basil (Ocimum basilicum) is a commonly used herb; it also contains essential oils and other valuable compounds. The basil oil obtained has a pleasant aroma, but also a broad spectrum of biological activity. This work reports on the chemical composition, antioxidant, [...] Read more.

Basil (Ocimum basilicum) is a commonly used herb; it also contains essential oils and other valuable compounds. The basil oil obtained has a pleasant aroma, but also a broad spectrum of biological activity. This work reports on the chemical composition, antioxidant, antimicrobial and anti-insect activity in vitro and in situ of Ocimum basilicum essential oil (OBEO) obtained by steam distillation of fresh flowering plants. Gas chromatography–mass spectrometry, DPPH, agar and disc diffusion and vapor phase methods were used to analyze the OBEO properties. The analysis of the chemical composition of OBEO showed that its main components were methyl chavicol (88.6%), 1,8-cineole (4.2%) and α-trans-bergamotene (1.7%). A strong antioxidant effect was demonstrated at the level of 77.3%. The analysis of antimicrobial properties showed that OBEO exerts variable strength of inhibiting activity against various groups of microorganisms. The growth inhibition zones ranged from 9.67 to 15.33 mm in Gram-positive (G⁺) and Gram-negative (G⁻) bacteria and from 5.33 to 7.33 mm in yeast. The lowest measured minimal inhibition concentration (MIC) was 3.21 µL/mL against Gram-negative Azotobacter chrococcum and Gram-positive Micrococcus luteus. The antimicrobial activity of in situ vapor phase of OBEO was also confirmed on apples, pears, potatoes and kohlrabi. The highest insecticidal activity against Pyrrhocorisapterus, observed at the concentration of 100%, caused the death of 80% of individuals. Due to its broad spectrum of activity, OBEO seems an ideal candidate for preserving fruit and vegetables. Full article

(This article belongs to the Special Issue Plant-Based Products and Ingredients: Isolation, Characterization, Bioactivity and Applications in Several Industries)

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13 pages, 2928 KiB

Open AccessEditor’s ChoiceArticle

Allelopathy in Durum Wheat Landraces as Affected by Genotype and Plant Part

by Aurelio Scavo, Gaetano Pandino, Alessia Restuccia, Paolo Caruso, Sara Lombardo and Giovanni Mauromicale

Plants 2022, 11(8), 1021; https://doi.org/10.3390/plants11081021 - 8 Apr 2022

Cited by 19 | Viewed by 3077

Abstract

Durum wheat is one of the largest cultivated crops across Mediterranean areas. The high demand for sustainable crop productions, especially concerning weed management, is driving the return to local landraces. In the present work, the in vitro allelopathic effects of the extracts of [...] Read more.

Durum wheat is one of the largest cultivated crops across Mediterranean areas. The high demand for sustainable crop productions, especially concerning weed management, is driving the return to local landraces. In the present work, the in vitro allelopathic effects of the extracts of three durum wheat landraces (‘Timilia’, ‘Russello’ and ‘Perciasacchi’) and a modern variety (‘Mongibello’), obtained from three different plant parts (ears, stems and roots), were tested on seed germination (G) and mean germination time (MGT) of Portulaca oleracea L. and Stellaria. media (L.) Vill., two weeds commonly infesting wheat fields. In addition, the total polyphenol (TPC) and total flavonoid (TFC) content of extracts was determined. All extracts reduced G and increased MGT in both weeds compared to the control. The magnitude of phytotoxicity was strongly affected by the influence of genotype, plant part and extract dilution. Overall, the landraces ‘Timilia’ and ‘Russello’ showed the highest allelopathic effects, ear extracts were the most active, and the maximum extract dilution induced higher phytotoxicity. Extracts’ TPC and TFC corroborated these results. The findings obtained here encourage the use of local landraces as a source of allelochemicals and suggest that they could be left on soil surface or soil-incorporated after harvest for a possible weed control. Full article

(This article belongs to the Special Issue Sustainable Weed Management)

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16 pages, 2383 KiB

Open AccessEditor’s ChoiceArticle

Targeted Gene Mutations in the Forest Pathogen Dothistroma septosporum Using CRISPR/Cas9

by Hannah M. McCarthy, Mariana Tarallo, Carl H. Mesarich, Rebecca L. McDougal and Rosie E. Bradshaw

Plants 2022, 11(8), 1016; https://doi.org/10.3390/plants11081016 - 8 Apr 2022

Cited by 4 | Viewed by 2519

Abstract

Dothistroma needle blight, caused by Dothistroma septosporum, has increased in incidence and severity over the last few decades and is now one of the most important global diseases of pines. Disease resistance breeding could be accelerated by knowledge of pathogen virulence factors [...] Read more.

Dothistroma needle blight, caused by Dothistroma septosporum, has increased in incidence and severity over the last few decades and is now one of the most important global diseases of pines. Disease resistance breeding could be accelerated by knowledge of pathogen virulence factors and their host targets. However, this is hindered due to inefficient targeted gene disruption in D. septosporum, which is required for virulence gene characterisation. Here we report the first successful application of CRISPR/Cas9 gene editing to a Dothideomycete forest pathogen, D. septosporum. Disruption of the dothistromin pathway regulator gene AflR, with a known phenotype, was performed using nonhomologous end-joining repair with an efficiency of >90%. Transformants with a range of disruption mutations in AflR were produced. Disruption of Ds74283, a D. septosporum gene encoding a secreted cell death elicitor, was also achieved using CRISPR/Cas9, by using a specific donor DNA repair template to aid selection where the phenotype was unknown. In this case, 100% of screened transformants were identified as disruptants. In establishing CRISPR/Cas9 as a tool for gene editing in D. septosporum, our research could fast track the functional characterisation of candidate virulence factors in D. septosporum and helps set the foundation for development of this technology in other forest pathogens. Full article

(This article belongs to the Special Issue Pathogenic Dothideomycete-Plant Interactions)

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15 pages, 3652 KiB

Open AccessEditor’s ChoiceArticle

Influence of Light Intensity and Spectrum on Duckweed Growth and Proteins in a Small-Scale, Re-Circulating Indoor Vertical Farm

by Finn Petersen, Johannes Demann, Dina Restemeyer, Hans-Werner Olfs, Heiner Westendarp, Klaus-Juergen Appenroth and Andreas Ulbrich

Plants 2022, 11(8), 1010; https://doi.org/10.3390/plants11081010 - 7 Apr 2022

Cited by 17 | Viewed by 5523

Abstract

Duckweeds can be potentially used in human and animal nutrition, biotechnology or wastewater treatment. To cultivate large quantities of a defined product quality, a standardized production process is needed. A small-scale, re-circulating indoor vertical farm (IVF) with artificial lighting and a nutrient control [...] Read more.

Duckweeds can be potentially used in human and animal nutrition, biotechnology or wastewater treatment. To cultivate large quantities of a defined product quality, a standardized production process is needed. A small-scale, re-circulating indoor vertical farm (IVF) with artificial lighting and a nutrient control and dosing system was used for this purpose. The influence of different light intensities (50, 100 and 150 µmol m⁻² s⁻¹) and spectral distributions (red/blue ratios: 70/30, 50/50 and 30/70%) on relative growth rate (RGR), crude protein content (CPC), relative protein yield (RPY) and chlorophyll a of the duckweed species Lemna minor and Wolffiella hyalina were investigated. Increasing light intensity increased RGR (by 67% and 76%) and RPY (by 50% and 89%) and decreased chlorophyll a (by 27% and 32%) for L. minor and W. hyalina, respectively. The spectral distributions had no significant impact on any investigated parameter. Wolffiella hyalina achieved higher values in all investigated parameters compared to L. minor. This investigation proved the successful cultivation of duckweed in a small-scale, re-circulating IVF with artificial lighting. Full article

(This article belongs to the Special Issue Duckweed: Research Meets Applications)

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17 pages, 1330 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

The Dynamics of Phosphorus Uptake and Remobilization during the Grain Development Period in Durum Wheat Plants

by Mohamed El Mazlouzi, Christian Morel, Thierry Robert, Coralie Chesseron, Christophe Salon, Jean-Yves Cornu and Alain Mollier

Plants 2022, 11(8), 1006; https://doi.org/10.3390/plants11081006 - 7 Apr 2022

Cited by 6 | Viewed by 2459

Abstract

Post-anthesis phosphorus (P) uptake and the remobilization of the previously acquired P are the principal sources of grain P nutrition in wheat. However, how the acquired P reaches the grains and its partitioning at the whole plant level remain poorly understood. Here, the [...] Read more.

Post-anthesis phosphorus (P) uptake and the remobilization of the previously acquired P are the principal sources of grain P nutrition in wheat. However, how the acquired P reaches the grains and its partitioning at the whole plant level remain poorly understood. Here, the temporal dynamics of the newly acquired P in durum wheat organs and its allocation to grain were examined using pulse-chase

^{32}

P-labeling experiments at 5 and 14 days after anthesis. Durum wheat plants were grown hydroponically under high and low P supplies. Each labeling experiment lasted for 24 h. Plants were harvested 24, 48, and 96 h after labeling. Low and high P treatments significantly affected the allocation of the newly acquired P at the whole plant level. Three days (96 h) after the first

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P-labeling, 8% and 4% of the newly acquired P from exogenous solution were allocated to grains, 73% and 55% to the remainder aboveground organs, and 19% and 41% to the roots at low and high P supplies, respectively. Three days after the second labeling, the corresponding values were 48% and 20% in grains, 44% and 53% in the remainder aboveground organs, and 8% and 27% in roots at low and high P supplies, respectively. These results reveal that the dynamics of P allocation to grain was faster in plants grown under low P supply than under high supply. However, the obtained results also indicate that the origin of P accumulated in durum wheat grains was mainly from P remobilization with little contribution from post-anthesis P uptake. The present study emphasizes the role of vegetative organs as temporary storage of P taken up during the grain filling period before its final allocation to grains. Full article

(This article belongs to the Special Issue Plant Nutrition Volume II)

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30 pages, 897 KiB

Open AccessEditor’s ChoiceReview

Signal Transduction in Cereal Plants Struggling with Environmental Stresses: From Perception to Response

by Małgorzata Nykiel, Marta Gietler, Justyna Fidler, Beata Prabucka, Anna Rybarczyk-Płońska, Jakub Graska, Dominika Boguszewska-Mańkowska, Ewa Muszyńska, Iwona Morkunas and Mateusz Labudda

Plants 2022, 11(8), 1009; https://doi.org/10.3390/plants11081009 - 7 Apr 2022

Cited by 14 | Viewed by 3351

Abstract

Cereal plants under abiotic or biotic stressors to survive unfavourable conditions and continue growth and development, rapidly and precisely identify external stimuli and activate complex molecular, biochemical, and physiological responses. To elicit a response to the stress factors, interactions between reactive oxygen and [...] Read more.

Cereal plants under abiotic or biotic stressors to survive unfavourable conditions and continue growth and development, rapidly and precisely identify external stimuli and activate complex molecular, biochemical, and physiological responses. To elicit a response to the stress factors, interactions between reactive oxygen and nitrogen species, calcium ions, mitogen-activated protein kinases, calcium-dependent protein kinases, calcineurin B-like interacting protein kinase, phytohormones and transcription factors occur. The integration of all these elements enables the change of gene expression, and the release of the antioxidant defence and protein repair systems. There are still numerous gaps in knowledge on these subjects in the literature caused by the multitude of signalling cascade components, simultaneous activation of multiple pathways and the intersection of their individual elements in response to both single and multiple stresses. Here, signal transduction pathways in cereal plants under drought, salinity, heavy metal stress, pathogen, and pest attack, as well as the crosstalk between the reactions during double stress responses are discussed. This article is a summary of the latest discoveries on signal transduction pathways and it integrates the available information to better outline the whole research problem for future research challenges as well as for the creative breeding of stress-tolerant cultivars of cereals. Full article

(This article belongs to the Special Issue Abiotic Stress Signaling and Responses in Plants)

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11 pages, 2763 KiB

Open AccessEditor’s ChoiceArticle

Systematic Analysis of the Molecular Mechanisms of Cold and Hot Properties of Herbal Medicines

by Sang-Min Park, Su-Jin Baek, Hyo-Jeong Ban, Hee-Jeong Jin and Seongwon Cha

Plants 2022, 11(7), 997; https://doi.org/10.3390/plants11070997 - 6 Apr 2022

Cited by 7 | Viewed by 2415

Abstract

Effective treatments for patients experiencing temperature-related symptoms are limited. The hot and cold effects of traditional herbal medicines have been utilized to treat and manage these symptoms, but their molecular mechanisms are not fully understood. Previous studies with arbitrarily selected herbs and ingredients [...] Read more.

Effective treatments for patients experiencing temperature-related symptoms are limited. The hot and cold effects of traditional herbal medicines have been utilized to treat and manage these symptoms, but their molecular mechanisms are not fully understood. Previous studies with arbitrarily selected herbs and ingredients may have produced biased results. Here, we aim to systematically elucidate the molecular mechanisms of the hot and cold properties of herbal medicines through an unbiased large-scale investigation of herbal ingredients, their target genes, and the transcriptome signatures induced by them. Using data regarding 243 herbs retrieved from two herbal medicine databases, we statistically identify (R)-Linalool, (-)-alpha-pinene, peruviol, (L)-alpha-terpineol, and cymol as five new hot-specific ingredients that share a common target, a norepinephrine transporter. However, no significant ingredients are cold-specific. We also statistically identify 14 hot- and 8 cold-specific new target genes. Pathway enrichment analysis of hot-specific target genes reveals the associated pathways including neurotransmitter reuptake, cold-induced thermogenesis, blood pressure regulation, adrenergic receptor signaling, and cation symporter activity. Cold-specific target genes are associated with the steroid pathway. Transcriptome analysis also shows that hot herbs are more strongly associated with coagulation and synaptic transmission than cold herbs. Our results, obtained from novel connections between herbal ingredients, target genes, and pathways, may contribute to the development of pharmacological treatment strategies for temperature-related pain using medicinal plants. Full article

(This article belongs to the Special Issue Pharmacological and Toxicological Study of Medicinal Plants)

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11 pages, 516 KiB

Open AccessFeature PaperEditor’s ChoiceReview

Rising Carbon Dioxide and Global Nutrition: Evidence and Action Needed

by Lewis H. Ziska

Plants 2022, 11(7), 1000; https://doi.org/10.3390/plants11071000 - 6 Apr 2022

Cited by 13 | Viewed by 3935

Abstract

While the role of CO₂ as a greenhouse gas in the context of global warming is widely acknowledged, additional data from multiple sources is demonstrating that rising CO₂ of and by itself will have a tremendous effect on plant biology. This [...] Read more.

While the role of CO₂ as a greenhouse gas in the context of global warming is widely acknowledged, additional data from multiple sources is demonstrating that rising CO₂ of and by itself will have a tremendous effect on plant biology. This effect is widely recognized for its role in stimulating photosynthesis and growth for multiple plant species, including crops. However, CO₂ is also likely to alter plant chemistry in ways that will denigrate plant nutrition. That role is also of tremendous importance, not only from a human health viewpoint, but also from a global food–web perspective. Here, the goal is to review the current evidence, propose potential mechanistic explanations, provide an overview of critical unknowns and to elucidate a series of next steps that can address what is, overall, a critical but unappreciated aspect of anthropogenic climate change. Full article

(This article belongs to the Special Issue The Effect of Carbon Dioxide Concentration on Plant Physiology)

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15 pages, 2193 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Impact of Grazing on Diversity of Semi-Arid Rangelands in Crete Island in the Context of Climatic Change

by Maria Karatassiou, Zoi M. Parissi, Sampson Panajiotidis and Afroditi Stergiou

Plants 2022, 11(7), 982; https://doi.org/10.3390/plants11070982 - 4 Apr 2022

Cited by 4 | Viewed by 2150

Abstract

The rangelands of Crete island (Greece) are typical Mediterranean habitats under high risk of degradation due to long-term grazing and harsh climatic conditions. We explored the effect of abiotic (climatic conditions, altitude) and biotic factors (long-term grazing by small ruminants) on the floristic [...] Read more.

The rangelands of Crete island (Greece) are typical Mediterranean habitats under high risk of degradation due to long-term grazing and harsh climatic conditions. We explored the effect of abiotic (climatic conditions, altitude) and biotic factors (long-term grazing by small ruminants) on the floristic composition and diversity of selected lowland (Pyrathi, Faistos) and highland (Vroulidia, Nida) rangelands. In each rangeland, the ground cover was measured, and the floristic composition was calculated in terms of five functional groups: grasses, legumes, forbs, phrygana, and shrubs. The aridity index, species turnover, species richness, Shannon entropy, and Gini–Simpson index (with the latter two converted to the effective number of species) were calculated. Our results reveal that highlands are characterized by the highest aridity index (wetter conditions). Lowland rangelands, compared to highland, exhibited a higher percentage contribution of grasses, legumes, and forbs, while species turnover decreased along the altitudinal gradient. The Shannon entropy index was correlated (a) positively with Gini–Simpson and mean annual temperature and (b) negatively with mean annual precipitation, aridity index, and altitude. Moreover, the Gini–Simpson index correlated positively with mean annual temperature and negatively with altitude. Our results could help to understand the effects of grazing on rangeland dynamics and sustainability in semi-arid regions in the context of climatic change. Full article

(This article belongs to the Special Issue Mediterranean Plants)

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14 pages, 2108 KiB

Open AccessEditor’s ChoiceArticle

Molecular and Pathogenic Characterization of Cylindrocarpon-like Anamorphs Causing Root and Basal Rot of Almonds

by Nieves Capote, María Ángeles Del Río, Juan Francisco Herencia and Francisco Teodoro Arroyo

Plants 2022, 11(7), 984; https://doi.org/10.3390/plants11070984 - 4 Apr 2022

Cited by 7 | Viewed by 2616

Abstract

Three almond nurseries were prospected in the South of Spain (Sevilla) to evaluate the sanitary status of the nursery plant material. Samples consisted of main roots, secondary roots and six-month-old basal stems ‘GxN-15’, ‘Nemaguard’, ‘Cadaman’, ‘Rootpac-40’ and ‘Rootpac-20’ rootstocks planted in the soil, [...] Read more.

Three almond nurseries were prospected in the South of Spain (Sevilla) to evaluate the sanitary status of the nursery plant material. Samples consisted of main roots, secondary roots and six-month-old basal stems ‘GxN-15’, ‘Nemaguard’, ‘Cadaman’, ‘Rootpac-40’ and ‘Rootpac-20’ rootstocks planted in the soil, and twigs of mother plants from ‘Lauranne’, ‘Guara’, ‘Marcona’, ‘Marta’ and ‘Ferragnes’ almond cultivars. Endophytic and potential pathogenic fungi were identified in mother plants and 70 Cylindrocarpon-like anamorph isolates were detected in the root system and basal stems of analyzed rootstocks. Based on partial sequencing of the his3 gene and multilocus phylogenetic analysis of the concatenated ITS, tub2, his3 and tef1-α partial sequences, seven Cylindrocarpon-like anamorph species were identified as Dactylonectria torresensis, D. novozelandica, D. macrodidyma, Ilyonectria liriodendri, Neonectria sp. 1, N. quercicola and Cylindrocladiella variabilis. Pathogenicity was assessed on young healthy detached twigs of ‘Guara’ almond cultivar and one-year-old ‘Lauranne’ potted almonds grafted onto ‘GxN-15’ rootstocks. Among the seven Cylindrocarpon-like anamorph species, I. liriodendri, Neonectria sp. 1 and N. quercicola were the most aggressive. Inoculated detached shoots developed necrotic lesions 15 days after inoculation. Inoculated trees showed sectorized necrosis in the main and secondary roots and the basal stem of the rootstock 5 months after inoculation. The most aggressive species were able to cause necrosis also in the grafted cultivar, and I. liriodendri, and N. quercicola also reduced the root biomass. This is the first report of Cylindrocarpon-like anamorph species causing root and basal rot of almonds. Full article

(This article belongs to the Special Issue New and Re-emerging Plant Diseases and Pathogens)

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15 pages, 2110 KiB

Open AccessEditor’s ChoiceArticle

Smart Glass Film Reduced Ascorbic Acid in Red and Orange Capsicum Fruit Cultivars without Impacting Shelf Life

by Xin He, Sachin G. Chavan, Ziad Hamoui, Chelsea Maier, Oula Ghannoum, Zhong-Hua Chen, David T. Tissue and Christopher I. Cazzonelli

Plants 2022, 11(7), 985; https://doi.org/10.3390/plants11070985 - 4 Apr 2022

Cited by 8 | Viewed by 2472

Abstract

Smart Glass Film (SGF) is a glasshouse covering material designed to permit 80% transmission of photosynthetically active light and block heat-generating solar energy. SGF can reduce crop water and nutrient consumption and improve glasshouse energy use efficiency yet can reduce crop yield. The [...] Read more.

Smart Glass Film (SGF) is a glasshouse covering material designed to permit 80% transmission of photosynthetically active light and block heat-generating solar energy. SGF can reduce crop water and nutrient consumption and improve glasshouse energy use efficiency yet can reduce crop yield. The effect of SGF on the postharvest shelf life of fruits remains unknown. Two capsicum varieties, Red (Gina) and Orange (O06614), were cultivated within a glasshouse covered in SGF to assess fruit quality and shelf life during the winter season. SGF reduced cuticle thickness in the Red cultivar (5%) and decreased ascorbic acid in both cultivars (9–14%) without altering the overall morphology of the mature fruits. The ratio of total soluble solids (TSSs) to titratable acidity (TA) was significantly higher in Red (29%) and Orange (89%) cultivars grown under SGF. The Red fruits had a thicker cuticle that reduced water loss and extended shelf life when compared to the Orange fruits, yet neither water loss nor firmness were impacted by SGF. Reducing the storage temperature to 2 °C and increasing relative humidity to 90% extended the shelf life in both cultivars without evidence of chilling injury. In summary, SGF had minimal impact on fruit development and postharvest traits and did not compromise the shelf life of mature fruits. SGF provides a promising technology to block heat-generating solar radiation energy without affecting fruit ripening and marketable quality of capsicum fruits grown during the winter season. Full article

(This article belongs to the Special Issue Improving the Performance, Resilience and Quality of Horticultural Crops in Controlled Environments)

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15 pages, 5131 KiB

Open AccessEditor’s ChoiceArticle

Genome-Wide Identification, Expression Pattern and Sequence Variation Analysis of SnRK Family Genes in Barley

by Jiangyan Xiong, Danyi Chen, Tingting Su, Qiufang Shen, Dezhi Wu and Guoping Zhang

Plants 2022, 11(7), 975; https://doi.org/10.3390/plants11070975 - 3 Apr 2022

Cited by 3 | Viewed by 2621

Abstract

Sucrose non-fermenting 1 (SNF1)-related protein kinase (SnRK) is a large family of protein kinases that play a significant role in plant stress responses. Although intensive studies have been conducted on SnRK members in some crops, little is known about the SnRK in barley. [...] Read more.

Sucrose non-fermenting 1 (SNF1)-related protein kinase (SnRK) is a large family of protein kinases that play a significant role in plant stress responses. Although intensive studies have been conducted on SnRK members in some crops, little is known about the SnRK in barley. Using phylogenetic and conserved motif analyses, we discovered 46 SnRK members scattered across barley’s 7 chromosomes and classified them into 3 sub-families. The gene structures of HvSnRKs showed the divergence among three subfamilies. Gene duplication and synteny analyses on the genomes of barley and rice revealed the evolutionary features of HvSnRKs. The promoter regions of HvSnRK family genes contained many ABRE, MBS and LTR elements responding to abiotic stresses, and their expression patterns varied with different plant tissues and abiotic stresses. HvSnRKs could interact with the components of ABA signaling pathway to respond to abiotic stress. Moreover, the haplotypes of HvSnRK2.5 closely associated with drought tolerance were detected in a barley core collection. The current results could be helpful for further exploration of the HvSnRK genes responding to abiotic stress tolerance in barley. Full article

(This article belongs to the Special Issue Physiological and Genetic Mechanisms of Abiotic Stress Tolerance in Crops)

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22 pages, 2148 KiB

Open AccessEditor’s ChoiceReview

Machine Learning for Plant Stress Modeling: A Perspective towards Hormesis Management

by Amanda Kim Rico-Chávez, Jesus Alejandro Franco, Arturo Alfonso Fernandez-Jaramillo, Luis Miguel Contreras-Medina, Ramón Gerardo Guevara-González and Quetzalcoatl Hernandez-Escobedo

Plants 2022, 11(7), 970; https://doi.org/10.3390/plants11070970 - 2 Apr 2022

Cited by 25 | Viewed by 5250

Abstract

Plant stress is one of the most significant factors affecting plant fitness and, consequently, food production. However, plant stress may also be profitable since it behaves hormetically; at low doses, it stimulates positive traits in crops, such as the synthesis of specialized metabolites [...] Read more.

Plant stress is one of the most significant factors affecting plant fitness and, consequently, food production. However, plant stress may also be profitable since it behaves hormetically; at low doses, it stimulates positive traits in crops, such as the synthesis of specialized metabolites and additional stress tolerance. The controlled exposure of crops to low doses of stressors is therefore called hormesis management, and it is a promising method to increase crop productivity and quality. Nevertheless, hormesis management has severe limitations derived from the complexity of plant physiological responses to stress. Many technological advances assist plant stress science in overcoming such limitations, which results in extensive datasets originating from the multiple layers of the plant defensive response. For that reason, artificial intelligence tools, particularly Machine Learning (ML) and Deep Learning (DL), have become crucial for processing and interpreting data to accurately model plant stress responses such as genomic variation, gene and protein expression, and metabolite biosynthesis. In this review, we discuss the most recent ML and DL applications in plant stress science, focusing on their potential for improving the development of hormesis management protocols. Full article

(This article belongs to the Special Issue Plant Computational Biology)

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15 pages, 53581 KiB

Open AccessEditor’s ChoiceArticle

Effect of Sucrose on Growth and Stress Status of Castanea sativa x C. crenata Shoots Cultured in Liquid Medium

by Diego Gago, María Ángeles Bernal, Conchi Sánchez, Anxela Aldrey, Beatriz Cuenca, Colin Bruce Christie and Nieves Vidal

Plants 2022, 11(7), 965; https://doi.org/10.3390/plants11070965 - 1 Apr 2022

Cited by 14 | Viewed by 2777

Abstract

Current breeding programs aim to increase the number of ink-tolerant chestnut trees using vegetative propagation of selected genotypes. However, the commercial vegetative propagation of chestnut species is still a bottleneck for the forest industry, mainly due to problems in the rooting and acclimation [...] Read more.

Current breeding programs aim to increase the number of ink-tolerant chestnut trees using vegetative propagation of selected genotypes. However, the commercial vegetative propagation of chestnut species is still a bottleneck for the forest industry, mainly due to problems in the rooting and acclimation of propagules. This study aimed to explore the potential benefits of decreasing sucrose supplementation during chestnut micropropagation. Explants were cultured with high light intensity and CO₂-enriched air in temporary or continuous immersion bioreactors and with different sucrose supplementation to evaluate the impact of these treatments on growth, rooting and physiological status (monosaccharide content, soluble phenolics and antioxidant activity). The proliferation and rooting performance of shoots cultured by continuous immersion decreased sharply with sucrose concentrations lower than 1%, whereas shoots cultured by temporary immersion grew and rooted successfully with 0.5% sucrose. These results suggest this system is appropriate to culture chestnut with low sucrose concentration and to explore photoautotrophic propagation of this species. Full article

(This article belongs to the Special Issue Application of Biotechnology to Woody Propagation)

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21 pages, 1416 KiB

Open AccessEditor’s ChoiceReview

Biochemistry and Molecular Basis of Intracellular Flavonoid Transport in Plants

by Boas Pucker and Dirk Selmar

Plants 2022, 11(7), 963; https://doi.org/10.3390/plants11070963 - 1 Apr 2022

Cited by 26 | Viewed by 11905

Abstract

Flavonoids are a biochemically diverse group of specialized metabolites in plants that are derived from phenylalanine. While the biosynthesis of the flavonoid aglycone is highly conserved across species and well characterized, numerous species-specific decoration steps and their relevance remained largely unexplored. The flavonoid [...] Read more.

Flavonoids are a biochemically diverse group of specialized metabolites in plants that are derived from phenylalanine. While the biosynthesis of the flavonoid aglycone is highly conserved across species and well characterized, numerous species-specific decoration steps and their relevance remained largely unexplored. The flavonoid biosynthesis takes place at the cytosolic side of the endoplasmatic reticulum (ER), but accumulation of various flavonoids was observed in the central vacuole. A universal explanation for the subcellular transport of flavonoids has eluded researchers for decades. Current knowledge suggests that a glutathione S-transferase-like protein (ligandin) protects anthocyanins and potentially proanthocyanidin precursors during the transport to the central vacuole. ABCC transporters and to a lower extend MATE transporters sequester anthocyanins into the vacuole. Glycosides of specific proanthocyanidin precursors are sequestered through MATE transporters. A P-ATPase in the tonoplast and potentially other proteins generate the proton gradient that is required for the MATE-mediated antiport. Vesicle-mediated transport of flavonoids from the ER to the vacuole is considered as an alternative or additional route. Full article

(This article belongs to the Special Issue Evolution of Specialized Metabolism in Plants)

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15 pages, 3131 KiB

Open AccessEditor’s ChoiceArticle

Metabolomic Profiling of Citrus unshiu during Different Stages of Fruit Development

by Sang Suk Kim, Hyun-Jin Kim, Kyung Jin Park, Seok Beom Kang, YoSup Park, Seong-Gab Han, Misun Kim, Yeong Hun Song and Dong-Shin Kim

Plants 2022, 11(7), 967; https://doi.org/10.3390/plants11070967 - 1 Apr 2022

Cited by 15 | Viewed by 2962

Abstract

Citrus fruits undergo significant metabolic profile changes during their development process. However, limited information is available on the changes in the metabolites of Citrus unshiu during fruit development. Here, we analyzed the total phenolic content (TPC), total carotenoid content (TCC), antioxidant activity, and [...] Read more.

Citrus fruits undergo significant metabolic profile changes during their development process. However, limited information is available on the changes in the metabolites of Citrus unshiu during fruit development. Here, we analyzed the total phenolic content (TPC), total carotenoid content (TCC), antioxidant activity, and metabolite profiles in C. unshiu fruit flesh during different stages of fruit development and evaluated their correlations. The TPC and antioxidant activity significantly decreased during fruit development, whereas the TCC increased. The metabolite profiles, including sugars, acidic compounds, amino acids, flavonoids, limonoids, carotenoids, and volatile compounds (mono- and sesquiterpenes), in C. unshiu fruit flesh also changed significantly, and a citrus metabolomic pathway related to fruit development was proposed. Based on the data, C. unshiu fruit development was classified into three groups: Group 1 (Aug. 1), Group 2 (Aug. 31 and Sep. 14), and Group 3 (Oct. 15 and Nov. 16). Although citrus peel was not analyzed and the sensory and functional qualities during fruit development were not investigated, the results of this study will help in our understanding of the changes in chemical profile during citrus fruit development. This can provide vital information for various applications in the C. unshiu industry. Full article

(This article belongs to the Section Plant Physiology and Metabolism)

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16 pages, 1620 KiB

Open AccessEditor’s ChoiceArticle

Chemical Composition, Antioxidant, and Antimicrobial Activity of Dracocephalum moldavica L. Essential Oil and Hydrolate

by Milica Aćimović, Olja Šovljanski, Vanja Šeregelj, Lato Pezo, Valtcho D. Zheljazkov, Jovana Ljujić, Ana Tomić, Gordana Ćetković, Jasna Čanadanović-Brunet, Ana Miljković and Ljubodrag Vujisić

Plants 2022, 11(7), 941; https://doi.org/10.3390/plants11070941 - 31 Mar 2022

Cited by 22 | Viewed by 2714

Abstract

Steam distillation was used for the isolation of Dracocephalum moldavica L. (Moldavian dragonhead) essential oil (DMEO). This aromatic herbaceous plant is widespread across the Northern Hemisphere regions and has been utilized in health-improving studies and applications. In addition to the DMEO, the hydrolate [...] Read more.

Steam distillation was used for the isolation of Dracocephalum moldavica L. (Moldavian dragonhead) essential oil (DMEO). This aromatic herbaceous plant is widespread across the Northern Hemisphere regions and has been utilized in health-improving studies and applications. In addition to the DMEO, the hydrolate (DMH), a byproduct of the distillation process, was also collected. The DMEO and DMH were analyzed and compared in terms of their chemical composition, as well as their in vitro biological activities. The main component in DMEO was geranyl acetate, while geranial was dominant in DMH. The DMEO demonstrated better antioxidant and antimicrobial activities compared with the DMH against Staphylococcus aureus, Escherichia coli, Salmonella Typhimurium, and Listeria monocytogenes, which represent sources of food-borne illness at the global level. The DMEO and DMH show promise as antioxidant and antimicrobial additives to various products. Full article

(This article belongs to the Special Issue New Insights in the Research of Bioactive Compounds from Plant Origin with Nutraceutical and Pharmaceutical Potential)

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22 pages, 1423 KiB

Open AccessFeature PaperEditor’s ChoiceReview

Genetic Characteristics and Metabolic Interactions between Pseudocercospora fijiensis and Banana: Progress toward Controlling Black Sigatoka

by Roslyn D. Noar, Elizabeth Thomas and Margaret E. Daub

Plants 2022, 11(7), 948; https://doi.org/10.3390/plants11070948 - 31 Mar 2022

Cited by 8 | Viewed by 4732

Abstract

The international importance of banana and severity of black Sigatoka disease have led to extensive investigations into the genetic characteristics and metabolic interactions between the Dothideomycete Pseudocercospora fijiensis and its banana host. P. fijiensis was shown to have a greatly expanded genome compared [...] Read more.

The international importance of banana and severity of black Sigatoka disease have led to extensive investigations into the genetic characteristics and metabolic interactions between the Dothideomycete Pseudocercospora fijiensis and its banana host. P. fijiensis was shown to have a greatly expanded genome compared to other Dothideomycetes, due to the proliferation of retrotransposons. Genome analysis suggests the presence of dispensable chromosomes that may aid in fungal adaptation as well as pathogenicity. Genomic research has led to the characterization of genes and metabolic pathways involved in pathogenicity, including: secondary metabolism genes such as PKS10-2, genes for mitogen-activated protein kinases such as Fus3 and Slt2, and genes for cell wall proteins such as glucosyl phosphatidylinositol (GPI) and glycophospholipid surface (Gas) proteins. Studies conducted on resistance mechanisms in banana have documented the role of jasmonic acid and ethylene pathways. With the development of banana transformation protocols, strategies for engineering resistance include transgenes expressing antimicrobial peptides or hydrolytic enzymes as well as host-induced gene silencing (HIGS) targeting pathogenicity genes. Pseudocercospora fijiensis has been identified as having high evolutionary potential, given its large genome size, ability to reproduce both sexually and asexually, and long-distance spore dispersal. Thus, multiple control measures are needed for the sustainable control of black Sigatoka disease. Full article

(This article belongs to the Special Issue Pathogenic Dothideomycete-Plant Interactions)

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17 pages, 2067 KiB

Open AccessEditor’s ChoiceArticle

Supercritical Fluid and Conventional Extractions of High Value-Added Compounds from Pomegranate Peels Waste: Production, Quantification and Antimicrobial Activity of Bioactive Constituents

by Kaja Kupnik, Maja Leitgeb, Mateja Primožič, Vesna Postružnik, Petra Kotnik, Nika Kučuk, Željko Knez and Maša Knez Marevci

Plants 2022, 11(7), 928; https://doi.org/10.3390/plants11070928 - 30 Mar 2022

Cited by 18 | Viewed by 2740

Abstract

This study is focused on different extractions (Cold Maceration (CM), Ultrasonic Extraction (UE), Soxhlet Extraction (SE) and Supercritical Fluid Extraction (SFE)) of bioactive compounds from pomegranate (Punica Granatum L.) fruit peels using methanol, ethanol, and acetone as solvents in conventional extractions and [...] Read more.

This study is focused on different extractions (Cold Maceration (CM), Ultrasonic Extraction (UE), Soxhlet Extraction (SE) and Supercritical Fluid Extraction (SFE)) of bioactive compounds from pomegranate (Punica Granatum L.) fruit peels using methanol, ethanol, and acetone as solvents in conventional extractions and changing operating pressure (10, 15, 20, 25 MPa) in SFE, respectively. The extraction yields, total phenols (TP) and proanthocyanidins (PAC) contents, and antioxidant activity of different extracts are revealed. TP and PAC recovered by extracts ranged from 24.22 to 42.92 mg gallic acid equivalents (GAE)/g and 2.01 to 5.82 mg PAC/g, respectively. The antioxidant activity of extracts ranged from 84.70% to 94.35%. The phenolic compound identification and quantification in selective extracts was done using the LC-MS/MS method. The contents of different flavonoids and phenolic acids have been determined. SFE extract, obtained at 20 MPa, contained the highest content (11,561.84 μg/g) of analyzed total polyphenols, with predominant ellagic acid (7492.53 μg/g). For the first time, Microbial Growth Inhibition Rates (MGIRs) were determined at five different concentrations of pomegranate SFE extract against seven microorganisms. Minimal Inhibitory Concentration (MIC₉₀) was determined as 2.7 mg/mL of SFE pomegranate peel extract in the case of five different Gram-negative and Gram-positive bacteria. Full article

(This article belongs to the Special Issue Trends in Plants Phytochemistry and Bioactivity Analysis)

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13 pages, 3102 KiB

Open AccessEditor’s ChoiceArticle

Hydrogen Sulfide Promotes Adventitious Root Development in Cucumber under Salt Stress by Enhancing Antioxidant Ability

by Yayu Liu, Lijuan Wei, Li Feng, Meiling Zhang, Dongliang Hu, Jianzhong Tie and Weibiao Liao

Plants 2022, 11(7), 935; https://doi.org/10.3390/plants11070935 - 30 Mar 2022

Cited by 22 | Viewed by 2073

Abstract

As a gas signal molecule, hydrogen sulfide (H₂S) can enhance plant stress resistance. Here, cucumber (Cucumis sativus ‘Xinchun NO. 4’) explants were used to investigate the role of H₂S in adventitious root development under salt stress. The results [...] Read more.

As a gas signal molecule, hydrogen sulfide (H₂S) can enhance plant stress resistance. Here, cucumber (Cucumis sativus ‘Xinchun NO. 4’) explants were used to investigate the role of H₂S in adventitious root development under salt stress. The results show that sodium chloride (NaCl) at 10 mM produced moderate salt stress. The 100 µM sodium hydrosulfide (NaHS) treatment, a H₂S donor, increased root number and root length by 38.37% and 66.75%, respectively, indicating that H₂S effectively promoted the occurrence of adventitious roots in cucumber explants under salt stress. The results show that under salt stress, NaHS treatment reduced free proline content and increased the soluble sugar and soluble protein content during rooting. Meanwhile, NaHS treatment enhanced the activities of antioxidant enzymes [peroxidase (POD), superoxide dismutase (SOD), ascorbate peroxidase (APX) and catalase (CAT)], increased the content of ascorbic (ASA) and glutathione (GSH), reduced the content of hydrogen peroxide (H₂O₂) and the rate of superoxide radical (O²⁻) production, and decreased relative electrical conductivity (REC) and the content of malondialdehyde (MDA). However, the NaHS scavenger hypotaurine (HT) reversed the above effects of NaHS under salt stress. In summary, H₂S promoted adventitious root development under salt stress through regulating osmotic substance content and enhancing antioxidant ability in explants. Full article

(This article belongs to the Special Issue Regulation of Abiotic Stress Responses in Vegetable Crops)

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17 pages, 807 KiB

Open AccessEditor’s ChoiceReview

Drought Stress Responses: Coping Strategy and Resistance

by Hanna Bandurska

Plants 2022, 11(7), 922; https://doi.org/10.3390/plants11070922 - 29 Mar 2022

Cited by 54 | Viewed by 6658

Abstract

Plants’ resistance to stress factors is a complex trait that is a result of changes at the molecular, metabolic, and physiological levels. The plant resistance strategy means the ability to survive, recover, and reproduce under adverse conditions. Harmful environmental factors affect the state [...] Read more.

Plants’ resistance to stress factors is a complex trait that is a result of changes at the molecular, metabolic, and physiological levels. The plant resistance strategy means the ability to survive, recover, and reproduce under adverse conditions. Harmful environmental factors affect the state of stress in plant tissues, which creates a signal triggering metabolic events responsible for resistance, including avoidance and/or tolerance mechanisms. Unfortunately, the term ‘stress resistance’ is often used in the literature interchangeably with ‘stress tolerance’. This paper highlights the differences between the terms ‘stress tolerance’ and ‘stress resistance’, based on the results of experiments focused on plants’ responses to drought. The ability to avoid or tolerate dehydration is crucial in the resistance to drought at cellular and tissue levels (biological resistance). However, it is not necessarily crucial in crop resistance to drought if we take into account agronomic criteria (agricultural resistance). For the plant user (farmer, grower), resistance to stress means not only the ability to cope with a stress factor, but also the achievement of a stable yield and good quality. Therefore, it is important to recognize both particular plant coping strategies (stress avoidance, stress tolerance) and their influence on the resistance, assessed using well-defined criteria. Full article

(This article belongs to the Special Issue 10th Anniversary of Plants—Recent Advances and Perspectives)

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