Plants

21 pages, 5569 KiB

Open AccessEditor’s ChoiceArticle

Inactivation of H⁺-ATPase Participates in the Influence of Variation Potential on Photosynthesis and Respiration in Peas

by Lyubov Yudina, Oksana Sherstneva, Ekaterina Sukhova, Marina Grinberg, Sergey Mysyagin, Vladimir Vodeneev and Vladimir Sukhov

Plants 2020, 9(11), 1585; https://doi.org/10.3390/plants9111585 - 16 Nov 2020

Cited by 18 | Viewed by 2559

Abstract

Local damage (e.g., burning, heating, or crushing) causes the generation and propagation of a variation potential (VP), which is a unique electrical signal in higher plants. A VP influences numerous physiological processes, with photosynthesis and respiration being important targets. VP generation is based [...] Read more.

Local damage (e.g., burning, heating, or crushing) causes the generation and propagation of a variation potential (VP), which is a unique electrical signal in higher plants. A VP influences numerous physiological processes, with photosynthesis and respiration being important targets. VP generation is based on transient inactivation of H⁺-ATPase in plasma membrane. In this work, we investigated the participation of this inactivation in the development of VP-induced photosynthetic and respiratory responses. Two- to three-week-old pea seedlings (Pisum sativum L.) and their protoplasts were investigated. Photosynthesis and respiration in intact seedlings were measured using a GFS-3000 gas analyzer, Dual-PAM-100 Pulse-Amplitude-Modulation (PAM)-fluorometer, and a Dual-PAM gas-exchange Cuvette 3010-Dual. Electrical activity was measured using extracellular electrodes. The parameters of photosynthetic light reactions in protoplasts were measured using the Dual-PAM-100; photosynthesis- and respiration-related changes in O₂ exchange rate were measured using an Oxygraph Plus System. We found that preliminary changes in the activity of H⁺-ATPase in the plasma membrane (its inactivation by sodium orthovanadate or activation by fusicoccin) influenced the amplitudes and magnitudes of VP-induced photosynthetic and respiratory responses in intact seedlings. Decreases in H⁺-ATPase activity (sodium orthovanadate treatment) induced fast decreases in photosynthetic activity and increases in respiration in protoplasts. Thus, our results support the effect of H⁺-ATPase inactivation on VP-induced photosynthetic and respiratory responses. Full article

(This article belongs to the Special Issue Long-Distance Signals and Systemic Adaptation Response on Action of Stressors in Plants)

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52 pages, 502 KiB

Open AccessEditor’s ChoiceReview

Phytotoxic Effects and Mechanism of Action of Essential Oils and Terpenoids

by Mercedes Verdeguer, Adela M. Sánchez-Moreiras and Fabrizio Araniti

Plants 2020, 9(11), 1571; https://doi.org/10.3390/plants9111571 - 13 Nov 2020

Cited by 105 | Viewed by 9197

Abstract

Weeds are one of the major constraints in crop production affecting both yield and quality. The excessive and exclusive use of synthetic herbicides for their management is increasing the development of herbicide-resistant weeds and is provoking risks for the environment and human health. [...] Read more.

Weeds are one of the major constraints in crop production affecting both yield and quality. The excessive and exclusive use of synthetic herbicides for their management is increasing the development of herbicide-resistant weeds and is provoking risks for the environment and human health. Therefore, the development of new herbicides with multitarget-site activity, new modes of action and low impact on the environment and health are badly needed. The study of plant–plant interactions through the release of secondary metabolites could be a starting point for the identification of new molecules with herbicidal activity. Essential oils (EOs) and their components, mainly terpenoids, as pure natural compounds or in mixtures, because of their structural diversity and strong phytotoxic activity, could be good candidates for the development of new bioherbicides or could serve as a basis for the development of new natural-like low impact synthetic herbicides. EOs and terpenoids have been largely studied for their phytotoxicity and several evidences on their modes of action have been highlighted in the last decades through the use of integrated approaches. The review is focused on the knowledge concerning the phytotoxicity of these molecules, their putative target, as well as their potential mode of action. Full article

(This article belongs to the Special Issue Biosynthesis and Functions of Terpenoids in Plants)

15 pages, 3954 KiB

Open AccessEditor’s ChoiceArticle

Arabidopsis Response to Inhibitor of Cytokinin Degradation INCYDE: Modulations of Cytokinin Signaling and Plant Proteome

by Veronika Berková, Michaela Kameniarová, Vladěna Ondrisková, Miroslav Berka, Simona Menšíková, Romana Kopecká, Markéta Luklová, Jan Novák, Lukáš Spíchal, Aaron M. Rashotte, Břetislav Brzobohatý and Martin Černý

Plants 2020, 9(11), 1563; https://doi.org/10.3390/plants9111563 - 13 Nov 2020

Cited by 16 | Viewed by 3761

Abstract

Cytokinins are multifaceted plant hormones that play crucial roles in plant interactions with the environment. Modulations in cytokinin metabolism and signaling have been successfully used for elevating plant tolerance to biotic and abiotic stressors. Here, we analyzed Arabidopsis thaliana response to INhibitor of [...] Read more.

Cytokinins are multifaceted plant hormones that play crucial roles in plant interactions with the environment. Modulations in cytokinin metabolism and signaling have been successfully used for elevating plant tolerance to biotic and abiotic stressors. Here, we analyzed Arabidopsis thaliana response to INhibitor of CYtokinin DEgradation (INCYDE), a potent inhibitor of cytokinin dehydrogenase. We found that at low nanomolar concentration, the effect of INCYCE on seedling growth and development was not significantly different from that of trans-Zeatin treatment. However, an alteration in the spatial distribution of cytokinin signaling was found at low micromolar concentrations, and proteomics analysis revealed a significant impact on the molecular level. An in-depth proteome analysis of an early (24 h) response and a dose-dependent response after 168 h highlighted the effects on primary and secondary metabolism, including alterations in ribosomal subunits, RNA metabolism, modulations of proteins associated with chromatin, and the flavonoid and phenylpropanoid biosynthetic pathway. The observed attenuation in stress-response mechanisms, including abscisic acid signaling and the metabolism of jasmonates, could explain previously reported positive effects of INCYDE under mild stress conditions. Full article

(This article belongs to the Special Issue Regulation of Abiotic and Biotic Stress Responses by Plant Hormones: Recent Advances)

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28 pages, 3882 KiB

Open AccessEditor’s ChoiceArticle

Extreme Drought Affects Visitation and Seed Set in a Plant Species in the Central Chilean Andes Heavily Dependent on Hummingbird Pollination

by Mary T. K. Arroyo, Valeria Robles, Ítalo Tamburrino, Jaime Martínez-Harms, René D. Garreaud, Paola Jara-Arancio, Patricio Pliscoff, Ana Copier, Jonás Arenas, Joaquín Keymer and Kiara Castro

Plants 2020, 9(11), 1553; https://doi.org/10.3390/plants9111553 - 12 Nov 2020

Cited by 15 | Viewed by 4055

Abstract

Rising temperatures and increasing drought in Mediterranean-type climate areas are expected to affect plant–pollinator interactions, especially in plant species with specialised pollination. Central Chile experienced a mega drought between 2010 and 2020 which reached an extreme in the austral summer of 2019–2020. Based [...] Read more.

Rising temperatures and increasing drought in Mediterranean-type climate areas are expected to affect plant–pollinator interactions, especially in plant species with specialised pollination. Central Chile experienced a mega drought between 2010 and 2020 which reached an extreme in the austral summer of 2019–2020. Based on intensive pollinator sampling and floral studies we show that the subalpine form of Mutisia subulata (Asteraceae) is a specialised hummingbird-pollinated species. In a two-year study which included the severest drought year, we quantified visitation frequency, flower-head density, flower-head visitation rates, two measures of floral longevity, nectar characteristics and seed set and monitored climatic variables to detect direct and indirect climate-related effects on pollinator visitation. Flower-head density, nectar standing crop and seed set were significantly reduced in the severest drought year while nectar concentration increased. The best model to explain visitation frequency included flower-head density, relative humidity, temperature, and nectar standing crop with highly significant effects of the first three variables. Results for flower-head density suggest hummingbirds were able to associate visual signals with reduced resource availability and/or were less abundant. The negative effect of lower relative humidity suggests the birds were able to perceive differences in nectar concentration. Reduced seed set per flower-head together with the availability of far fewer ovules in the 2019–2020 austral summer would have resulted in a major reduction in seed set. Longer and more intense droughts in this century could threaten local population persistence in M. subulata. Full article

(This article belongs to the Special Issue Plant-Pollinator Interactions in Mediterranean-Type Ecosystems)

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19 pages, 6506 KiB

Open AccessEditor’s ChoiceArticle

In Silico Identification of MYB and bHLH Families Reveals Candidate Transcription Factors for Secondary Metabolic Pathways in Cannabis sativa L.

by Laura Bassolino, Matteo Buti, Flavia Fulvio, Alessandro Pennesi, Giuseppe Mandolino, Justyna Milc, Enrico Francia and Roberta Paris

Plants 2020, 9(11), 1540; https://doi.org/10.3390/plants9111540 - 11 Nov 2020

Cited by 17 | Viewed by 5185

Abstract

Plant secondary metabolic pathways are finely regulated by the activity of transcription factors, among which members of the bHLH and MYB subfamilies play a main role. Cannabis sativa L. is a unique officinal plant species with over 600 synthesized phytochemicals having diverse scale-up [...] Read more.

Plant secondary metabolic pathways are finely regulated by the activity of transcription factors, among which members of the bHLH and MYB subfamilies play a main role. Cannabis sativa L. is a unique officinal plant species with over 600 synthesized phytochemicals having diverse scale-up industrial and pharmaceutical usage. Despite comprehensive knowledge of cannabinoids’ metabolic pathways, very little is known about their regulation, while the literature on flavonoids’ metabolic pathways is still scarce. In this study, we provide the first genome-wide analysis of bHLH and MYB families in C. sativa reference cultivar CBDRx and identification of candidate coding sequences for these transcription factors. Cannabis sativa bHLHs and MYBs were then classified into functional subfamilies through comparative phylogenetic analysis with A. thaliana transcription factors. Analyses of gene structure and motif distribution confirmed that CsbHLHs and CsMYBs belonging to the same evolutionary clade share common features at both gene and amino acidic level. Candidate regulatory genes for key metabolic pathways leading to flavonoid and cannabinoid synthesis in Cannabis were also retrieved. Furthermore, a candidate gene approach was used to identify structural enzyme-coding genes for flavonoid and cannabinoid synthesis. Taken as a whole, this work represents a valuable resource of candidate genes for further investigation of the C. sativa cannabinoid and flavonoid metabolic pathways for genomic studies and breeding programs. Full article

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

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16 pages, 9577 KiB

Open AccessEditor’s ChoiceArticle

Light Quality Affected the Growth and Root Organic Carbon and Autotoxin Secretions of Hydroponic Lettuce

by Chengbo Zhou, Yubin Zhang, Wenke Liu, Lingyan Zha, Mingjie Shao and Baoshi Li

Plants 2020, 9(11), 1542; https://doi.org/10.3390/plants9111542 - 11 Nov 2020

Cited by 23 | Viewed by 4057

Abstract

Light is a crucial environmental signal and photosynthetic energy for plant growth, development, and primary and secondary metabolism. To explore the effects of light quality on the growth and root exudates of hydroponic lettuce (Lactuca sativa L.), white LED (W, control) and [...] Read more.

Light is a crucial environmental signal and photosynthetic energy for plant growth, development, and primary and secondary metabolism. To explore the effects of light quality on the growth and root exudates of hydroponic lettuce (Lactuca sativa L.), white LED (W, control) and four the mixtures of red (R) and blue (B) LED with different R/B light intensity ratios (R/B = 2, 2R1B; R/B = 3, 3R1B; R/B = 4, 4R1B; and R/B = 8, 8R1B) were designed. The results showed that the biomass of lettuce under 8R1B and W treatments was higher than that under other light quality treatments. The photosynthetic rate (Pn) under red and blue light was significantly higher than that of white light. Total root length, root surface area, and root volume were the highest under 8R1B. 4R1B treatment significant increased root activity by 68.6% compared with W. In addition, total organic carbon (TOC) content, TOC content/shoot dry weight, TOC content/root dry weight, and TOC content/root surface area were the highest under 4R1B. Moreover, 8R1B treatment reduced the concentration of benzoic acid and salicylic acid, and the secretion ability of benzoic acid and salicylic acid by per unit root surface area and accumulation by per unit shoot dry weight. In addition, 2R1B and 3R1B reduced the secretion ability of gallic acid and tannic acid by per unit root surface area and accumulation by per unit shoot dry weight. In conclusion, this study showed that the secretion of autotoxins could be reduced through the mediation of red and blue light composition of LEDs in a plant factory. In terms of autotoxin secretion reduction efficiency and yield performance of lettuce, 8R1B light regime is recommended for practical use. Full article

(This article belongs to the Special Issue Applications and Advances in Artificial Light for Horticulture and Crop Production)

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15 pages, 1756 KiB

Open AccessEditor’s ChoiceReview

Function and Mechanism of WRKY Transcription Factors in Abiotic Stress Responses of Plants

by Weixing Li, Siyu Pang, Zhaogeng Lu and Biao Jin

Plants 2020, 9(11), 1515; https://doi.org/10.3390/plants9111515 - 8 Nov 2020

Cited by 193 | Viewed by 10570

Abstract

The WRKY gene family is a plant-specific transcription factor (TF) group, playing important roles in many different response pathways of diverse abiotic stresses (drought, saline, alkali, temperature, and ultraviolet radiation, and so forth). In recent years, many studies have explored the role and [...] Read more.

The WRKY gene family is a plant-specific transcription factor (TF) group, playing important roles in many different response pathways of diverse abiotic stresses (drought, saline, alkali, temperature, and ultraviolet radiation, and so forth). In recent years, many studies have explored the role and mechanism of WRKY family members from model plants to agricultural crops and other species. Abiotic stress adversely affects the growth and development of plants. Thus, a review of WRKY with stress responses is important to increase our understanding of abiotic stress responses in plants. Here, we summarize the structural characteristics and regulatory mechanism of WRKY transcription factors and their responses to abiotic stress. We also discuss current issues and future perspectives of WRKY transcription factor research. Full article

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

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27 pages, 1645 KiB

Open AccessEditor’s ChoiceArticle

Physiological and Biochemical Changes in Sugar Beet Seedlings to Confer Stress Adaptability under Drought Condition

by Md. Jahirul Islam, Ji Woong Kim, Mst. Kohinoor Begum, Md. Abu Taher Sohel and Young-Seok Lim

Plants 2020, 9(11), 1511; https://doi.org/10.3390/plants9111511 - 7 Nov 2020

Cited by 50 | Viewed by 4776

Abstract

The present study was conducted to examine the adaptability of 11 sugar beet cultivars grown under drought stress in the controlled glasshouse. The treatment was initiated on 30-day-old sugar beet plants where drought stress was made withholding water supply for consecutive 10 days [...] Read more.

The present study was conducted to examine the adaptability of 11 sugar beet cultivars grown under drought stress in the controlled glasshouse. The treatment was initiated on 30-day-old sugar beet plants where drought stress was made withholding water supply for consecutive 10 days while control was done with providing water as per requirement. It was observed that drought stress expressively reduced plant growth, photosynthetic pigments, and photosynthetic quantum yield in all the cultivars but comparative better results were observed in S1 (MAXIMELLA), S2 (HELENIKA), S6 (RECODDINA), S8 (SV2347), and S11 (BSRI Sugarbeet 2) cultivars. Besides, osmolytes like proline, glycine betaine, total soluble carbohydrate, total soluble sugar, total polyphenol, total flavonoid, and DPPH free radical scavenging activity were remarkably increased under drought condition in MAXIMELLA, HELENIKA, TERRANOVA, GREGOIA, SV2348, and BSRI Sugar beet 2 cultivars. In contrast, activities of enzymes like superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) were significantly decreased in all, while the cultivars SV2347, BSRI Sugar beet 1 and BSRI Sugar beet 2 were found with increased ascorbate peroxidase (APX) activity under drought condition. In parallel, polyphenol oxidase (PPO) was increased in all cultivars except HELENIKA. Overall, the cultivars HELENIKA, RECODDINA, GREGOIA, SV2347, SV2348, BSRI Sugar beet 1, and BSRI Sugar beet 2 were found best fitted to the given drought condition. These findings would help further for the improvement of stress adaptive sugar beet cultivars development in the breeding program for drought-prone regions. Full article

(This article belongs to the Special Issue Effects of Abiotic Stress on Plants 2020–2021)

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9 pages, 988 KiB

Open AccessEditor’s ChoiceReview

Zinc (Zn): The Last Nutrient in the Alphabet and Shedding Light on Zn Efficiency for the Future of Crop Production under Suboptimal Zn

by Gokhan Hacisalihoglu

Plants 2020, 9(11), 1471; https://doi.org/10.3390/plants9111471 - 31 Oct 2020

Cited by 90 | Viewed by 9394

Abstract

At a global scale, about three billion people have inadequate zinc (Zn) and iron (Fe) nutrition and 500,000 children lose their lives due to this. In recent years, the interest in adopting healthy diets drew increased attention to mineral nutrients, including Zn. Zn [...] Read more.

At a global scale, about three billion people have inadequate zinc (Zn) and iron (Fe) nutrition and 500,000 children lose their lives due to this. In recent years, the interest in adopting healthy diets drew increased attention to mineral nutrients, including Zn. Zn is an essential micronutrient for plant growth and development that is involved in several processes, like acting as a cofactor for hundreds of enzymes, chlorophyll biosynthesis, gene expression, signal transduction, and plant defense systems. Many agricultural soils are unable to supply the Zn needs of crop plants, making Zn deficiency a widespread nutritional disorder, particularly in calcareous (pH > 7) soils worldwide. Plant Zn efficiency involves Zn uptake, transport, and utilization; plants with high Zn efficiency display high yield and significant growth under low Zn supply and offer a promising and sustainable solution for the production of many crops, such as rice, beans, wheat, soybeans, and maize. The goal of this review is to report the current knowledge on key Zn efficiency traits including root system uptake, Zn transporters, and shoot Zn utilization. These mechanisms will be valuable for increasing the Zn efficiency of crops and food Zn contents to meet global needs for food production and nutrition in the 21st century. Furthermore, future research will address the target genes underlying Zn efficiency and the optimization of Zn efficiency phenotyping for the development of Zn-efficient crop varieties for more sustainable crop production under suboptimal Zn regimes, as well food security of the future. Full article

(This article belongs to the Special Issue Unraveling the Mechanisms of Zn Efficiency in Crop Plants: From Lab to Field Applications)

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17 pages, 1317 KiB

Open AccessEditor’s ChoiceReview

Recent Advances Regarding the Phytochemical and Therapeutic Uses of Populus nigra L. Buds

by Brigitta Kis, Stefana Avram, Ioana Zinuca Pavel, Adelina Lombrea, Valentina Buda, Cristina Adriana Dehelean, Codruta Soica, Mukerrem Betul Yerer, Florina Bojin, Roxana Folescu and Corina Danciu

Plants 2020, 9(11), 1464; https://doi.org/10.3390/plants9111464 - 29 Oct 2020

Cited by 36 | Viewed by 5126

Abstract

Populus nigra L. (Salicaceae family) is one of the most popular trees that can be found in deciduous forests. Some particularities that characterize the Populus genus refer to the fact that it includes more than 40 species, being widespread especially in Europe and [...] Read more.

Populus nigra L. (Salicaceae family) is one of the most popular trees that can be found in deciduous forests. Some particularities that characterize the Populus genus refer to the fact that it includes more than 40 species, being widespread especially in Europe and Asia. Many residues, parts of this tree can be used as a bioresource for different extracts as active ingredients in pharmaceuticals next to multiple benefits in many areas of medicine. The present review discusses the latest findings regarding the phytochemical composition and the therapeutic properties of Populus nigra L. buds. The vegetal product has been described mainly to contain phenolic compounds (phenols, phenolic acids and phenylpropanoids), terpenoids (mono and sesquiterpenoids), flavones (e.g., apigenol and crysin), flavanones (e.g., pinocembrin and pinostrombin), caffeic/ferulic acids and their derivates, and more than 48 phytocompounds in the essential oils. The resinous exudates present on the buds have been the major plant source used by bees to form propolis. Several studies depicted its antioxidant, anti-inflammatory, antibacterial, antifungal, antidiabetic, antitumor, hepatoprotective, hypouricemic properties and its effects on melanin production. All these lead to the conclusion that black poplar buds are a valuable and important source of bioactive compounds responsible for a wide range of therapeutic uses, being a promising candidate as a complementary and/or alternative source for a large number of health problems. The aim of the review is to gather the existing information and to bring an up to date regarding the phytochemical and therapeutic uses of Populus nigra L. buds. Full article

(This article belongs to the Special Issue Natural Compounds–Successful Solutions for the Medical Challenges of the 21st Century)

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17 pages, 1659 KiB

Open AccessEditor’s ChoiceArticle

GIS-Facilitated Effective Propagation Protocols of the Endangered Local Endemic of Crete Carlina diae (Rech. f.) Meusel and A. Kástner (Asteraceae): Serving Ex Situ Conservation Needs and Its Future Sustainable Utilization as an Ornamental

by Katerina Grigoriadou, Virginia Sarropoulou, Nikos Krigas, Eleni Maloupa and Georgios Tsoktouridis

Plants 2020, 9(11), 1465; https://doi.org/10.3390/plants9111465 - 29 Oct 2020

Cited by 24 | Viewed by 3371

Abstract

Conservation and sustainable exploitation of threatened endemic plants with medicinal and/or horticultural/ornamental value can be achieved through the development of effective propagation protocols. After unveiling the bioclimatic preferences of Carlina diae (Asteraceae) with geographic information systems (GIS), four propagation trials were conducted using [...] Read more.

Conservation and sustainable exploitation of threatened endemic plants with medicinal and/or horticultural/ornamental value can be achieved through the development of effective propagation protocols. After unveiling the bioclimatic preferences of Carlina diae (Asteraceae) with geographic information systems (GIS), four propagation trials were conducted using seeds of this endangered local Cretan endemic for in vivo and in vitro germination, as well as seasonal vegetative propagation trials (softwood cuttings) and micropropagation (nodal explants). Seed germination was accomplished at a level of 77–90% in vivo (30 days) and 96% in vitro (10 days) using an MS medium with 2.9 μM gibberellic acid (GA₃). The optimum treatments for cuttings’ rooting were 1000 and 2000 ppm indole-3-butyric acid (IBA) (11–16 roots, 2–3 cm long, 100% rooting) within 40 days in mist. In vitro shoot propagation exhibited a 2.8 proliferation rate after six successive subcultures on an MS medium with 2.9 μM GA₃. Both ex vitro rooting and acclimatization were successful in 40 days, with 96% microshoot rooting and an equal survival rate. The GIS-facilitated effective species-specific propagation protocols developed in this study can consolidate the perspective of successful re-introduction of ex situ-raised material of C. diae into wild habitats and may serve its sustainable exploitation for high-added value ornamental products. Full article

(This article belongs to the Special Issue Taxonomy and Plant Conservation)

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23 pages, 10992 KiB

Open AccessEditor’s ChoiceArticle

Image-Based Plant Disease Identification by Deep Learning Meta-Architectures

by Muhammad Hammad Saleem, Sapna Khanchi, Johan Potgieter and Khalid Mahmood Arif

Plants 2020, 9(11), 1451; https://doi.org/10.3390/plants9111451 - 27 Oct 2020

Cited by 111 | Viewed by 11097

Abstract

The identification of plant disease is an imperative part of crop monitoring systems. Computer vision and deep learning (DL) techniques have been proven to be state-of-the-art to address various agricultural problems. This research performed the complex tasks of localization and classification of the [...] Read more.

The identification of plant disease is an imperative part of crop monitoring systems. Computer vision and deep learning (DL) techniques have been proven to be state-of-the-art to address various agricultural problems. This research performed the complex tasks of localization and classification of the disease in plant leaves. In this regard, three DL meta-architectures including the Single Shot MultiBox Detector (SSD), Faster Region-based Convolutional Neural Network (RCNN), and Region-based Fully Convolutional Networks (RFCN) were applied by using the TensorFlow object detection framework. All the DL models were trained/tested on a controlled environment dataset to recognize the disease in plant species. Moreover, an improvement in the mean average precision of the best-obtained deep learning architecture was attempted through different state-of-the-art deep learning optimizers. The SSD model trained with an Adam optimizer exhibited the highest mean average precision (mAP) of 73.07%. The successful identification of 26 different types of defected and 12 types of healthy leaves in a single framework proved the novelty of the work. In the future, the proposed detection methodology can also be adopted for other agricultural applications. Moreover, the generated weights can be reused for future real-time detection of plant disease in a controlled/uncontrolled environment. Full article

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29 pages, 1076 KiB

Open AccessEditor’s ChoiceReview

Innovative Extraction Techniques Using Deep Eutectic Solvents and Analytical Methods for the Isolation and Characterization of Natural Bioactive Compounds from Plant Material

by Milena Ivanović, Maša Islamčević Razboršek and Mitja Kolar

Plants 2020, 9(11), 1428; https://doi.org/10.3390/plants9111428 - 24 Oct 2020

Cited by 108 | Viewed by 14317

Abstract

The growing interest of the food, pharmaceutical and cosmetics industries in naturally occurring bioactive compounds or secondary plant metabolites also leads to a growing demand for the development of new and more effective analysis and isolation techniques. The extraction of bioactive compounds from [...] Read more.

The growing interest of the food, pharmaceutical and cosmetics industries in naturally occurring bioactive compounds or secondary plant metabolites also leads to a growing demand for the development of new and more effective analysis and isolation techniques. The extraction of bioactive compounds from plant material has always been a challenge, accompanied by increasingly strict control requirements for the final products and a growing interest in environmental protection. However, great efforts have been made in this direction and today a considerable number of innovative extraction techniques have been developed using green, environmentally friendly solvents. These solvents include the deep eutectic solvents (DES) and their natural equivalents, the natural deep eutectic solvents (NADES). Due to their adjustable physical-chemical properties and their green character, it is expected that DES/NADES could be the most widely used solvents in the future, not only in extraction processes but also in other research areas such as catalysis, electrochemistry or organic synthesis. Consequently, this review provided an up-to-date systematic overview of the use of DES/NADES in combination with innovative extraction techniques for the isolation of bioactive compounds from various plant materials. The topicality of the field was confirmed by a detailed search on the platform WoS (Web of Science), which resulted in more than 100 original research papers on DES/NADES for bioactive compounds in the last three years. Besides the isolation of bioactive compounds from plants, different analytical methods are presented and discussed. Full article

(This article belongs to the Special Issue Plant Analytical Chemistry)

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14 pages, 2636 KiB

Open AccessEditor’s ChoiceArticle

Antioxidant Responses of Phenolic Compounds and Immobilization of Copper in Imperata cylindrica, a Plant with Potential Use for Bioremediation of Cu Contaminated Environments

by Catalina Vidal, Antonieta Ruiz, Javier Ortiz, Giovanni Larama, Rodrigo Perez, Christian Santander, Paulo Ademar Avelar Ferreira and Pablo Cornejo

Plants 2020, 9(10), 1397; https://doi.org/10.3390/plants9101397 - 20 Oct 2020

Cited by 32 | Viewed by 3575

Abstract

This work examined the capability of Imperata cylindrica to respond, tolerate and accumulate Cu when growing at high Cu concentration (300 mg kg⁻¹ of substrate) at different times of exposure (2, 14 and 21 days). The Cu accumulation in plants was examined [...] Read more.

This work examined the capability of Imperata cylindrica to respond, tolerate and accumulate Cu when growing at high Cu concentration (300 mg kg⁻¹ of substrate) at different times of exposure (2, 14 and 21 days). The Cu accumulation in plants was examined by atomic absorption spectroscopy (AAS) and Cu localized by Scanning Electron Microscopy-Energy Dispersive X-Ray spectroscopy. Additionally, the phenolic compound identifications and concentrations were determined using liquid chromatography coupled to mass spectrometry. Our results showed that root biomass decreased significantly at high Cu levels, with a greater decrease at 21 days (39.8% less biomass in comparison to control). The root showed 328 mg Cu kg⁻¹ dry weight at 21 days of exposure to Cu, being the tissue that accumulates most of the Cu. Lipid peroxidation was a clear indicator of Cu stress, principally in shoots. The exposure to Cu significantly increased the synthesis of phenolic compounds in shoots of plants exposed 21 days to Cu, where 5-caffeoylquinic acid reached the highest concentrations. Our results support that I. cylindrica is a Cu accumulator plant in root organs with a medium level of accumulation (between 200–600 mg Cu kg⁻¹ biomass), which can tolerate the exposure to high Cu levels by means of increasing the synthesis of phenolic compound in shoots, suggesting a potential use as phytoremediation tool in Cu polluted environments. Full article

(This article belongs to the Special Issue Heavy Metal Stress in Plants)

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20 pages, 3237 KiB

Open AccessEditor’s ChoiceArticle

Effect of Cadmium-Tolerant Rhizobacteria on Growth Attributes and Chlorophyll Contents of Bitter Gourd under Cadmium Toxicity

by Muhammad Zafar-ul-Hye, Muhammad Naeem, Subhan Danish, Muhammad Jamil Khan, Shah Fahad, Rahul Datta, Martin Brtnicky, Antonin Kintl, Ghulam Sabir Hussain and Mohamed A. El-Esawi

Plants 2020, 9(10), 1386; https://doi.org/10.3390/plants9101386 - 17 Oct 2020

Cited by 67 | Viewed by 4926

Abstract

Cadmium (Cd) is one of the heavy metals that negatively affects the growth of plants. High solubilization in water leads Cd to enter into plants quite easily, thus decreasing seed germination, photosynthesis, and transpiration. It also shows an antagonistic effect with many of [...] Read more.

Cadmium (Cd) is one of the heavy metals that negatively affects the growth of plants. High solubilization in water leads Cd to enter into plants quite easily, thus decreasing seed germination, photosynthesis, and transpiration. It also shows an antagonistic effect with many of the plants’ nutrients like Mn, Ca, K, Mg and Fe. Nowadays, inoculation of plants with ACC deaminase (ACCD) rhizobacteria to mitigate Cd’s adverse effects has drawn the attention of environmental microbiologists. The rhizobacteria secrete organic compounds that can immobilize Cd in soil. Therefore, this study was accomplished to investigate the effect of ACCD plant growth promoting rhizobacteria (PGPR) on the bitter gourd under Cd stress. There were six treatments consisting of two ACCD PGPR (Stenotrophomonas maltophilia and Agrobacterium fabrum) strains and inorganic fertilizers at two levels of Cd, i.e., 2 (Cd2) and 5 mg kg⁻¹ soil (Cd5). The results showed A. fabrum with the recommended NPK fertilizer (RNPKF) significantly increased the vine length (48 and 55%), fresh weight (24 and 22%), and contents of chlorophyll a (79 and 50%), chlorophyll b (30 and 33%) and total chlorophyll (61 and 36%), over control at the two Cd levels i.e., Cd2 and Cd5, respectively. In conclusion, the recommended NPK fertilizer + A. fabrum combination is a very effective treatment with which to immobilize Cd in soil for the improvement of bitter gourd growth. Full article

(This article belongs to the Special Issue Heavy Metal Stress in Plants)

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22 pages, 1068 KiB

Open AccessEditor’s ChoiceReview

High-Throughput Sequencing Application in the Diagnosis and Discovery of Plant-Infecting Viruses in Africa, A Decade Later

by Jacques Davy Ibaba and Augustine Gubba

Plants 2020, 9(10), 1376; https://doi.org/10.3390/plants9101376 - 16 Oct 2020

Cited by 16 | Viewed by 5074

Abstract

High-throughput sequencing (HTS) application in the field of plant virology started in 2009 and has proven very successful for virus discovery and detection of viruses already known. Plant virology is still a developing science in most of Africa; the number of HTS-related studies [...] Read more.

High-throughput sequencing (HTS) application in the field of plant virology started in 2009 and has proven very successful for virus discovery and detection of viruses already known. Plant virology is still a developing science in most of Africa; the number of HTS-related studies published in the scientific literature has been increasing over the years as a result of successful collaborations. Studies using HTS to identify plant-infecting viruses have been conducted in 20 African countries, of which Kenya, South Africa and Tanzania share the most published papers. At least 29 host plants, including various agricultural economically important crops, ornamentals and medicinal plants, have been used in viromics analyses and have resulted in the detection of previously known viruses and novel ones from almost any host. Knowing that the effectiveness of any management program requires knowledge on the types, distribution, incidence, and genetic of the virus-causing disease, integrating HTS and efficient bioinformatics tools in plant virology research projects conducted in Africa is a matter of the utmost importance towards achieving and maintaining sustainable food security. Full article

(This article belongs to the Special Issue Diagnosis and Control of Plant Viral Diseases)

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17 pages, 3697 KiB

Open AccessEditor’s ChoiceArticle

Variability in the Qualitative and Quantitative Composition and Content of Phenolic Compounds in the Fruit of Introduced American Cranberry (Vaccinium macrocarpon Aiton)

by Ieva Gudžinskaitė, Elicija Stackevičienė, Mindaugas Liaudanskas, Kristina Zymonė, Vaidotas Žvikas, Jonas Viškelis, Rima Urbštaitė and Valdimaras Janulis

Plants 2020, 9(10), 1379; https://doi.org/10.3390/plants9101379 - 16 Oct 2020

Cited by 20 | Viewed by 3402

Abstract

The aim of this study was to determine the composition and content of phenolic compounds in ethanol extracts of eight different cultivars of American cranberry (Vaccinium macrocarpon Aiton) fruit using spectrophotometric and UPLC-ESI-MS/MS analysis and to evaluate the antioxidant activity in vitro [...] Read more.

The aim of this study was to determine the composition and content of phenolic compounds in ethanol extracts of eight different cultivars of American cranberry (Vaccinium macrocarpon Aiton) fruit using spectrophotometric and UPLC-ESI-MS/MS analysis and to evaluate the antioxidant activity in vitro of these extracts. The highest total amount of phenolic compounds evaluated via Folin–Ciocalteu spectrophotometry was detected in American cranberry fruit samples of the ‘Bain’ clone, and the highest total amount of flavonoids was found in samples of the ‘Drever’ and ‘Baiwfay’ cultivars. The highest total amount of the individual phenolic compounds (519.53 ± 25.12 mg/g DW) identified and quantitatively evaluated via chromatography was detected in samples of the ‘Searles’ cranberry cultivar. In the studied cranberry samples, the predominant phenolic compounds were hyperoside, quercetin, and procyanidin A2, while the amounts of other compounds were significantly lower. HCA and PCA revealed that ‘Woolman’, ‘Holliston’, ‘Pilgrim, and ‘Searles’ fruit samples had different quantitative content of phenolic compounds from other cranberry cultivars. Meanwhile, fruit of ‘Baiwfay’, ‘Drever’, ‘Bain’, and ‘Bergman’ were similar in their phytochemical profile. Full article

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

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21 pages, 2109 KiB

Open AccessEditor’s ChoiceArticle

Correction of Potassium Fertigation Rate of Apple Tree (Malus domestica Borkh.) in Central Russia during the Growing Season

by Andrei I. Kuzin, Natalia Ya. Kashirskaya, Anna M. Kochkina and Alexey V. Kushner

Plants 2020, 9(10), 1366; https://doi.org/10.3390/plants9101366 - 15 Oct 2020

Cited by 27 | Viewed by 3276

Abstract

The proper use of potassium fertilizer can stimulate a significant yield increase. However, the application of excessively high rates of potassium can reduce the availability of soil calcium for apple trees. The potassium fertigation rate must meet the apple tree’s requirements so that [...] Read more.

The proper use of potassium fertilizer can stimulate a significant yield increase. However, the application of excessively high rates of potassium can reduce the availability of soil calcium for apple trees. The potassium fertigation rate must meet the apple tree’s requirements so that the applied fertilizers can be absorbed by the roots as much as possible. Crop load in apple orchards sometimes varies significantly in different years. The potassium content in apple fruits is relatively high, and the maximum requirement for this nutrient occurs when fruits grow and ripen. Different crop loads at that time mean the various demands of trees and need for changing application rates for this nutrient. The investigation was carried out in the experimental orchard of I.V. Michurin Federal Scientific Centre (Michurinsk, Russia) in 2016 and 2017 (52.885131, 40.465613). We studied seasonal changes of potassium and calcium contents in soil, fruits, and leaves and their relationship with yield during the research. We paid much attention to the potassium rate shift on its content in leaves and fruits and cultivars “Lobo” and “Zhigulevskoye” yield. If the potassium application rate changes according to the actual crop load, it stimulates the yield growth or (if the crop load was relatively low) the reduction of the rate did not lower the productivity. Moreover, we studied the relationship between potassium and calcium nutrition. The decrease in potassium fertigation rate increased the availability of soil calcium. It was the reason for fruit calcium concentration enlargement and mitigation of the K/Ca ratio. We also specified some parameters for soil–leaf diagnosis for potassium nutrition during the growing season. Full article

(This article belongs to the Special Issue Physiological Responses of Tree Fruits to Environmental and Management Factors)

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14 pages, 1792 KiB

Open AccessEditor’s ChoiceArticle

Impact of Bulk ZnO, ZnO Nanoparticles and Dissolved Zn on Early Growth Stages of Barley—A Pot Experiment

by Lucia Nemček, Martin Šebesta, Martin Urík, Marek Bujdoš, Edmund Dobročka and Ivo Vávra

Plants 2020, 9(10), 1365; https://doi.org/10.3390/plants9101365 - 15 Oct 2020

Cited by 20 | Viewed by 3331

Abstract

Zinc is among the most in-demand metals in the world which also means that a considerable amount of this element is released to the environment each year as a result of human activities. A pot experiment was conducted to study the impact of [...] Read more.

Zinc is among the most in-demand metals in the world which also means that a considerable amount of this element is released to the environment each year as a result of human activities. A pot experiment was conducted to study the impact of low- and high-dose zinc amendments on plant growth and biomass yield, with Calcic Chernozem as a growing medium and barley (Hordeum vulgare L.) as a model plant. The distribution of zinc in various plant parts was also investigated. Zn (II) was added in powder as bulk ZnO and in solution as ZnO nanoparticles and ZnSO₄ in two dosages (3 and 30 mmol kg⁻¹ soil) prior to planting. The plants were harvested after 10 days of growth. The three sets of data were taken under identical experimental conditions. The application of zinc in aqueous solution and in particulate form (having particle sizes in the range of <100 nm to >500 nm) at concentration of 3 and 30 mmol Zn kg⁻¹ to the soil resulted in decreased growth (root length, shoot length) and biomass yield; the only exception was the addition of 30 mmol Zn kg⁻¹ in the form of bulk ZnO, which had a positive effect on the root growth. The dry weight reduction (sprout biomass) was lowest in plants grown in soil treated with dissolved zinc. There were no statistically significant changes in the content of chlorophyll a, chlorophyll b, and total chlorophyll, although flame atomic absorption spectrometry (FAAS) analysis indicated that plants bioaccumulated the zinc applied. This implies that the transport of zinc into the above-ground plant parts is controlled by the presence of effective mechanical and physiological barriers in roots. Crop performance under zinc stress in relation to biomass production and the growth of roots and shoots is also partly a reflection of the effects of soil properties. Our findings emphasize the importance of considering plant-soil interactions in research of potential toxicity and bioavailability of zinc in the environment. Full article

(This article belongs to the Special Issue Fundamental and Applied Research for the Effective Deployment of Phytoremediation)

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14 pages, 2730 KiB

Open AccessEditor’s ChoiceArticle

Spatial and Temporal Dynamics of Electrical and Photosynthetic Activity and the Content of Phytohormones Induced by Local Stimulation of Pea Plants

by Maria Ladeynova, Maxim Mudrilov, Ekaterina Berezina, Dmitry Kior, Marina Grinberg, Anna Brilkina, Vladimir Sukhov and Vladimir Vodeneev

Plants 2020, 9(10), 1364; https://doi.org/10.3390/plants9101364 - 15 Oct 2020

Cited by 14 | Viewed by 3145

Abstract

A local leaf burning causes variation potential (VP) propagation, a decrease in photosynthesis activity, and changes in the content of phytohormones in unstimulated leaves in pea plants. The VP-induced photosynthesis response develops in two phases: fast inactivation and long-term inactivation. Along with a [...] Read more.

A local leaf burning causes variation potential (VP) propagation, a decrease in photosynthesis activity, and changes in the content of phytohormones in unstimulated leaves in pea plants. The VP-induced photosynthesis response develops in two phases: fast inactivation and long-term inactivation. Along with a decrease in photosynthetic activity, there is a transpiration suppression in unstimulated pea leaves, which corresponds to the long-term phase of photosynthesis response. Phytohormone level analysis showed an increase in the concentration of jasmonic acid (JA) preceding a transpiration suppression and a long-term phase of the photosynthesis response. Analysis of the spatial and temporal dynamics of electrical signals, phytohormone levels, photosynthesis, and transpiration activity showed the most pronounced changes in the more distant leaf from the area of local stimulation. The established features are related to the architecture of the vascular bundles in the pea stem. Full article

(This article belongs to the Special Issue Long-Distance Signals and Systemic Adaptation Response on Action of Stressors in Plants)

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18 pages, 2880 KiB

Open AccessEditor’s ChoiceArticle

Metabolic Responses to Waterlogging Differ between Roots and Shoots and Reflect Phloem Transport Alteration in Medicago truncatula

by Jérémy Lothier, Houssein Diab, Caroline Cukier, Anis M. Limami and Guillaume Tcherkez

Plants 2020, 9(10), 1373; https://doi.org/10.3390/plants9101373 - 15 Oct 2020

Cited by 37 | Viewed by 3048

Abstract

Root oxygen deficiency that is induced by flooding (waterlogging) is a common situation in many agricultural areas, causing considerable loss in yield and productivity. Physiological and metabolic acclimation to hypoxia has mostly been studied on roots or whole seedlings under full submergence. The [...] Read more.

Root oxygen deficiency that is induced by flooding (waterlogging) is a common situation in many agricultural areas, causing considerable loss in yield and productivity. Physiological and metabolic acclimation to hypoxia has mostly been studied on roots or whole seedlings under full submergence. The metabolic difference between shoots and roots during waterlogging, and how roots and shoots communicate in such a situation is much less known. In particular, the metabolic acclimation in shoots and how this, in turn, impacts on roots metabolism is not well documented. Here, we monitored changes in the metabolome of roots and shoots of barrel clover (Medicago truncatula), growth, and gas-exchange, and analyzed phloem sap exudate composition. Roots exhibited a typical response to hypoxia, such as γ-aminobutyrate and alanine accumulation, as well as a strong decline in raffinose, sucrose, hexoses, and pentoses. Leaves exhibited a strong increase in starch, sugars, sugar derivatives, and phenolics (tyrosine, tryptophan, phenylalanine, benzoate, ferulate), suggesting an inhibition of sugar export and their alternative utilization by aromatic compounds production via pentose phosphates and phosphoenolpyruvate. Accordingly, there was an enrichment in sugars and a decline in organic acids in phloem sap exudates under waterlogging. Mass-balance calculations further suggest an increased imbalance between loading by shoots and unloading by roots under waterlogging. Taken as a whole, our results are consistent with the inhibition of sugar import by waterlogged roots, leading to an increase in phloem sugar pool, which, in turn, exert negative feedback on sugar metabolism and utilization in shoots. Full article

(This article belongs to the Special Issue Plant Responses to Hypoxia)

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19 pages, 614 KiB

Open AccessEditor’s ChoiceReview

Improving Horticultural Crops via CRISPR/Cas9: Current Successes and Prospects

by Bed Prakash Bhatta and Subas Malla

Plants 2020, 9(10), 1360; https://doi.org/10.3390/plants9101360 - 14 Oct 2020

Cited by 23 | Viewed by 8892

Abstract

Horticultural crops include a diverse array of crops comprising fruits, vegetables, nuts, flowers, aromatic and medicinal plants. They provide nutritional, medicinal, and aesthetic benefits to mankind. However, these crops undergo many biotic (e.g., diseases, pests) and abiotic stresses (e.g., drought, salinity). Conventional breeding [...] Read more.

Horticultural crops include a diverse array of crops comprising fruits, vegetables, nuts, flowers, aromatic and medicinal plants. They provide nutritional, medicinal, and aesthetic benefits to mankind. However, these crops undergo many biotic (e.g., diseases, pests) and abiotic stresses (e.g., drought, salinity). Conventional breeding strategies to improve traits in crops involve the use of a series of backcrossing and selection for introgression of a beneficial trait into elite germplasm, which is time and resource consuming. Recent new plant breeding tools such as clustered regularly interspaced short palindromic repeats (CRISPR) /CRISPR-associated protein-9 (Cas9) technique have the potential to be rapid, cost-effective, and precise tools for crop improvement. In this review article, we explore the CRISPR/Cas9 technology, its history, classification, general applications, specific uses in horticultural crops, challenges, existing resources, associated regulatory aspects, and the way forward. Full article

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19 pages, 3157 KiB

Open AccessEditor’s ChoiceArticle

Phytotoxicity, Morphological, and Metabolic Effects of the Sesquiterpenoid Nerolidol on Arabidopsis thaliana Seedling Roots

by Marco Landi, Biswapriya Biswavas Misra, Antonella Muto, Leonardo Bruno and Fabrizio Araniti

Plants 2020, 9(10), 1347; https://doi.org/10.3390/plants9101347 - 12 Oct 2020

Cited by 15 | Viewed by 3839

Abstract

Natural herbicides that are based on allelopathy of compounds, can offer effective alternatives to chemical herbicides towards sustainable agricultural practices. Nerolidol, a sesquiterpenoid alcohol synthesized by many plant families, was shown to be the most effective allelopathic compound in a preliminary screening performed [...] Read more.

Natural herbicides that are based on allelopathy of compounds, can offer effective alternatives to chemical herbicides towards sustainable agricultural practices. Nerolidol, a sesquiterpenoid alcohol synthesized by many plant families, was shown to be the most effective allelopathic compound in a preliminary screening performed with several other sesquiterpenoids. In the present study, Arabidopsis thaliana seedlings were treated for 14 d with various cis-nerolidol concentrations (0, 50, 100, 200, 400, and 800 µM) to investigate its effects on root growth and morphology. To probe the underlying changes in root metabolome, we conducted untargeted gas chromatography mass spectrometry (GC-MS) based metabolomics to find out the specificity or multi-target action of this sesquiterpenoid alcohol. Oxidative stress (measured as levels of H₂O₂ and malondialdehyde (MDA) by-product) and antioxidant enzyme activities, i.e., superoxide dismutase (SOD) and catalase (CAT) were also evaluated in the roots. Nerolidol showed an IC₅₀ (120 µM), which can be considered low for natural products. Nerolidol caused alterations in root morphology, brought changes in auxin balance, induced changes in sugar, amino acid, and carboxylic acid profiles, and increased the levels of H₂O₂ and MDA in root tissues in a dose-dependent manner. Several metabolomic-scale changes induced by nerolidol support the multi-target action of nerolidol, which is a positive feature for a botanical herbicide. Though it warrants further mechanistic investigation, nerolidol is a promising compound for developing a new natural herbicide. Full article

(This article belongs to the Special Issue Secondary Metabolites and Eco-friendly Techniques for Agricultural Weed/Pest Management)

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34 pages, 687 KiB

Open AccessEditor’s ChoiceReview

Zebrafish as a Successful Animal Model for Screening Toxicity of Medicinal Plants

by Amir Modarresi Chahardehi, Hasni Arsad and Vuanghao Lim

Plants 2020, 9(10), 1345; https://doi.org/10.3390/plants9101345 - 12 Oct 2020

Cited by 101 | Viewed by 12866

Abstract

The zebrafish (Danio rerio) is used as an embryonic and larval model to perform in vitro experiments and developmental toxicity studies. Zebrafish may be used to determine the toxicity of samples in early screening assays, often in a high-throughput manner. The [...] Read more.

The zebrafish (Danio rerio) is used as an embryonic and larval model to perform in vitro experiments and developmental toxicity studies. Zebrafish may be used to determine the toxicity of samples in early screening assays, often in a high-throughput manner. The zebrafish embryotoxicity model is at the leading edge of toxicology research due to the short time required for analyses, transparency of embryos, short life cycle, high fertility, and genetic data similarity. Zebrafish toxicity studies range from assessing the toxicity of bioactive compounds or crude extracts from plants to determining the optimal process. Most of the studied extracts were polar, such as ethanol, methanol, and aqueous solutions, which were used to detect the toxicity and bioactivity. This review examines the latest research using zebrafish as a study model and highlights its power as a tool for detecting toxicity of medicinal plants and its effectiveness at enhancing the understanding of new drug generation. The goal of this review was to develop a link to ethnopharmacological zebrafish studies that can be used by other researchers to conduct future research. Full article

(This article belongs to the Special Issue Structural and Functional Analysis of Extracts in Plants)

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9 pages, 2092 KiB

Open AccessEditor’s ChoiceCommunication

OsmiR535, a Potential Genetic Editing Target for Drought and Salinity Stress Tolerance in Oryza sativa

by Erkui Yue, Huan Cao and Bohan Liu

Plants 2020, 9(10), 1337; https://doi.org/10.3390/plants9101337 - 10 Oct 2020

Cited by 94 | Viewed by 4759

Abstract

OsmiR535 belongs to the miR156/miR529/miR535 superfamily, a highly conserved miRNA family in plants. OsmiR535 is involved in regulating the cold-stress response, modulating plant development, and determining panicle architecture and grain length. However, the role that OsmiR535 plays in plant responses to drought and [...] Read more.

OsmiR535 belongs to the miR156/miR529/miR535 superfamily, a highly conserved miRNA family in plants. OsmiR535 is involved in regulating the cold-stress response, modulating plant development, and determining panicle architecture and grain length. However, the role that OsmiR535 plays in plant responses to drought and salinity are elusive. In the current study, molecular and genetic engineering techniques were used to elucidate the possible role of OsmiR535 in response to NaCl, PEG(Poly ethylene glycol), ABA(Abscisic acid), and dehydration stresses. Our results showed that OsmiR535 is induced under stressed conditions as compared to control. With transgenic and CRISPR/Cas9 knockout system techniques, our results verified that either inhibition or knockout of OsmiR535 in rice could enhance the tolerance of plants to NaCl, ABA, dehydration and PEG stresses. In addition, the overexpression of OsmiR535 significantly reduced the survival rate of rice seedlings during PEG and dehydration post-stress recovery. Our results demonstrated that OsmiR535 negatively regulates the stress response in rice. Moreover, our practical application of CRISPR/Cas9 mediated genome editing created a homozygous 5 bp deletion in the coding sequence of OsmiR535, demonstrating that OsmiR535 could be a useful genetic editing target for drought and salinity tolerance and a new marker for molecular breeding of Oryza sativa. Full article

(This article belongs to the Special Issue Abiotic Stress Tolerance in Crop and Medical Plants)

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29 pages, 1361 KiB

Open AccessEditor’s ChoiceReview

Understanding Host–Pathogen Interactions in Brassica napus in the Omics Era

by Ting Xiang Neik, Junrey Amas, Martin Barbetti, David Edwards and Jacqueline Batley

Plants 2020, 9(10), 1336; https://doi.org/10.3390/plants9101336 - 10 Oct 2020

Cited by 30 | Viewed by 10744

Abstract

Brassica napus (canola/oilseed rape/rapeseed) is an economically important crop, mostly found in temperate and sub-tropical regions, that is cultivated widely for its edible oil. Major diseases of Brassica crops such as Blackleg, Clubroot, Sclerotinia Stem Rot, Downy Mildew, Alternaria Leaf Spot and White [...] Read more.

Brassica napus (canola/oilseed rape/rapeseed) is an economically important crop, mostly found in temperate and sub-tropical regions, that is cultivated widely for its edible oil. Major diseases of Brassica crops such as Blackleg, Clubroot, Sclerotinia Stem Rot, Downy Mildew, Alternaria Leaf Spot and White Rust have caused significant yield and economic losses in rapeseed-producing countries worldwide, exacerbated by global climate change, and, if not remedied effectively, will threaten global food security. To gain further insights into the host–pathogen interactions in relation to Brassica diseases, it is critical that we review current knowledge in this area and discuss how omics technologies can offer promising results and help to push boundaries in our understanding of the resistance mechanisms. Omics technologies, such as genomics, proteomics, transcriptomics and metabolomics approaches, allow us to understand the host and pathogen, as well as the interaction between the two species at a deeper level. With these integrated data in multi-omics and systems biology, we are able to breed high-quality disease-resistant Brassica crops in a more holistic, targeted and accurate way. Full article

(This article belongs to the Special Issue Omics in Plant-Pathogen Interaction)

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16 pages, 3892 KiB

Open AccessEditor’s ChoiceArticle

Artocarpus lakoocha Roxb. and Artocarpus heterophyllus Lam. Flowers: New Sources of Bioactive Compounds

by Arun Kumar Gupta, Muzamil Ahmad Rather, Avinash Kumar Jha, Abhinay Shashank, Somya Singhal, Maanas Sharma, Urbi Pathak, Dipti Sharma and Andrea Mastinu

Plants 2020, 9(10), 1329; https://doi.org/10.3390/plants9101329 - 9 Oct 2020

Cited by 65 | Viewed by 8203

Abstract

Artocarpus heterophyllus Lam. (AH) and Artocarpus lakoocha Roxb. (AL) are two endemic plants that grow on the Asian continent. To date, their applications have been aimed at using their fruit as a food source or for some of their [...] Read more.

Artocarpus heterophyllus Lam. (AH) and Artocarpus lakoocha Roxb. (AL) are two endemic plants that grow on the Asian continent. To date, their applications have been aimed at using their fruit as a food source or for some of their therapeutic virtues. In this study, attention was given to the flowers of AH and AL. Initially, the cytotoxicity of the phytoextracts was assessed, and the content of minerals, phenols, and flavonoids was determined. Furthermore, some antioxidant components were identified by HPLC. Furthermore, the ability of AH and AL extracts to modulate the gene expression of some targets involved in the antioxidant response was studied. The results obtained highlighted the nutritional and antioxidant value of the AH and AL flower extracts. This study will contribute to enhancing the use of AH and AL flowers as potential supplements in human nutrition. Full article

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16 pages, 16822 KiB

Open AccessEditor’s ChoiceArticle

Plant Disease Classification: A Comparative Evaluation of Convolutional Neural Networks and Deep Learning Optimizers

by Muhammad Hammad Saleem, Johan Potgieter and Khalid Mahmood Arif

Plants 2020, 9(10), 1319; https://doi.org/10.3390/plants9101319 - 6 Oct 2020

Cited by 148 | Viewed by 15423

Abstract

Recently, plant disease classification has been done by various state-of-the-art deep learning (DL) architectures on the publicly available/author generated datasets. This research proposed the deep learning-based comparative evaluation for the classification of plant disease in two steps. Firstly, the best convolutional neural network [...] Read more.

Recently, plant disease classification has been done by various state-of-the-art deep learning (DL) architectures on the publicly available/author generated datasets. This research proposed the deep learning-based comparative evaluation for the classification of plant disease in two steps. Firstly, the best convolutional neural network (CNN) was obtained by conducting a comparative analysis among well-known CNN architectures along with modified and cascaded/hybrid versions of some of the DL models proposed in the recent researches. Secondly, the performance of the best-obtained model was attempted to improve by training through various deep learning optimizers. The comparison between various CNNs was based on performance metrics such as validation accuracy/loss, F1-score, and the required number of epochs. All the selected DL architectures were trained in the PlantVillage dataset which contains 26 different diseases belonging to 14 respective plant species. Keras with TensorFlow backend was used to train deep learning architectures. It is concluded that the Xception architecture trained with the Adam optimizer attained the highest validation accuracy and F1-score of 99.81% and 0.9978 respectively which is comparatively better than the previous approaches and it proves the novelty of the work. Therefore, the method proposed in this research can be applied to other agricultural applications for transparent detection and classification purposes. Full article

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19 pages, 1174 KiB

Open AccessEditor’s ChoiceArticle

Transcriptome Analyses and Antioxidant Activity Profiling Reveal the Role of a Lignin-Derived Biostimulant Seed Treatment in Enhancing Heat Stress Tolerance in Soybean

by Cristina Campobenedetto, Giuseppe Mannino, Chiara Agliassa, Alberto Acquadro, Valeria Contartese, Christian Garabello and Cinzia Margherita Bertea

Plants 2020, 9(10), 1308; https://doi.org/10.3390/plants9101308 - 2 Oct 2020

Cited by 45 | Viewed by 5733

Abstract

Soybean (Glycine max Merr.) is a worldwide important legume crop, whose growth and yield are negatively affected by heat stress at germination time. Here, we tested the role of a biostimulant based on lignin derivatives, plant-derived amino acids, and molybdenum in enhancing [...] Read more.

Soybean (Glycine max Merr.) is a worldwide important legume crop, whose growth and yield are negatively affected by heat stress at germination time. Here, we tested the role of a biostimulant based on lignin derivatives, plant-derived amino acids, and molybdenum in enhancing soybean heat stress tolerance when applied on seeds. After treatment with the biostimulant at 35 °C, the seed biometric parameters were positively influenced after 24 h, meanwhile, germination percentage was increased after 72 h (+10%). RNA-Seq analyses revealed a modulation of 879 genes (51 upregulated and 828 downregulated) in biostimulant-treated seeds as compared with the control, at 24 h after incubation at 35 °C. Surprisingly, more than 33% of upregulated genes encoded for ribosomal RNA (rRNA) methyltransferases and proteins involved in the ribosome assembly, acting in a specific protein network. Conversely, the downregulated genes were involved in stress response, hormone signaling, and primary metabolism. Finally, from a biochemical point of view, the dramatic H₂O₂ reduction 40%) correlated to a strong increase in non-protein thiols (+150%), suggested a lower oxidative stress level in biostimulant-treated seeds, at 24 h after incubation at 35 °C. Our results provide insights on the biostimulant mechanism of action and on its application for seed treatments to improve heat stress tolerance during germination. Full article

(This article belongs to the Special Issue Biostimulants in Plants Science)

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18 pages, 16506 KiB

Open AccessFeature PaperEditor’s ChoiceReview

Crop Mass and N Status as Prerequisite Covariables for Unraveling Nitrogen Use Efficiency across Genotype-by-Environment-by-Management Scenarios: A Review

by Gilles Lemaire and Ignacio Ciampitti

Plants 2020, 9(10), 1309; https://doi.org/10.3390/plants9101309 - 2 Oct 2020

Cited by 65 | Viewed by 4731

Abstract

Due to the asymptotic nature of the crop yield response curve to fertilizer N supply, the nitrogen use efficiency (NUE, yield per unit of fertilizer applied) of crops declines as the crop N nutrition becomes less limiting. Therefore, it is difficult to directly [...] Read more.

Due to the asymptotic nature of the crop yield response curve to fertilizer N supply, the nitrogen use efficiency (NUE, yield per unit of fertilizer applied) of crops declines as the crop N nutrition becomes less limiting. Therefore, it is difficult to directly compare the NUE of crops according to genotype-by-environment-by-management interactions in the absence of any indication of crop N status. The determination of the nitrogen nutrition index (NNI) allows the estimation of crop N status independently of the N fertilizer application rate. Moreover, the theory of N dilution in crops indicates clearly that crop N uptake is coregulated by (i) soil N availability and (ii) plant growth rate capacity. Thus, according to genotype-by-environment-by-management interactions leading to variation in potential plant growth capacity, N demand for a given soil N supply condition would be different; consequently, the NUE of the crop would be dissimilar. We demonstrate that NUE depends on the crop potential growth rate and N status defined by the crop NNI. Thus, providing proper context to NUE changes needs to be achieved by considering comparisons with similar crop mass and NNI to avoid any misinterpretation. The latter needs to be considered not only when analyzing genotype-by-environment-by-management interactions for NUE but for other resource use efficiency inputs such as water use efficiency (colimitation N–water) under field conditions. Full article

(This article belongs to the Special Issue Improving Nitrogen-Use Efficiency at the Cropping System Scale: Agronomic and Genetic Aspects)

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14 pages, 294 KiB

Open AccessEditor’s ChoiceReview

The Potential of Payment for Ecosystem Services for Crop Wild Relative Conservation

by Nicholas Tyack, Hannes Dempewolf and Colin K. Khoury

Plants 2020, 9(10), 1305; https://doi.org/10.3390/plants9101305 - 2 Oct 2020

Cited by 24 | Viewed by 3889

Abstract

Crop wild relatives (CWR) have proven to be very valuable in agricultural breeding programs but remain a relatively under-utilized and under-protected resource. CWR have provided resistance to pests and diseases, abiotic stress tolerance, quality improvements and yield increases with the annual contribution of [...] Read more.

Crop wild relatives (CWR) have proven to be very valuable in agricultural breeding programs but remain a relatively under-utilized and under-protected resource. CWR have provided resistance to pests and diseases, abiotic stress tolerance, quality improvements and yield increases with the annual contribution of these traits to agriculture estimated at USD 115 billion globally and are considered to possess many valuable traits that have not yet been explored. The use of the genetic diversity found in CWR for breeding provides much-needed resilience to modern agricultural systems and has great potential to help sustainably increase agricultural production to feed a growing world population in the face of climate change and other stresses. A number of CWR taxa are at risk, however, necessitating coordinated local, national, regional and global efforts to preserve the genetic diversity of these plants through complementary in situ and ex situ conservation efforts. We discuss the absence of adequate institutional frameworks to incentivize CWR conservation services and propose payment for ecosystem services (PES) as an under-explored mechanism for financing these efforts. Such mechanisms could serve as a potentially powerful tool for enhancing the long-term protection of CWR. Full article

(This article belongs to the Special Issue Plant Biodiversity and Genetic Resources)

31 pages, 1815 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Germplasm Acquisition and Distribution by CGIAR Genebanks

by Michael Halewood, Nelissa Jamora, Isabel Lopez Noriega, Noelle L. Anglin, Peter Wenzl, Thomas Payne, Marie-Noelle Ndjiondjop, Luigi Guarino, P. Lava Kumar, Mariana Yazbek, Alice Muchugi, Vania Azevedo, Marimagne Tchamba, Chris S. Jones, Ramaiah Venuprasad, Nicolas Roux, Edwin Rojas and Charlotte Lusty

Plants 2020, 9(10), 1296; https://doi.org/10.3390/plants9101296 - 1 Oct 2020

Cited by 32 | Viewed by 7885

Abstract

The international collections of plant genetic resources for food and agriculture (PGRFA) hosted by 11 CGIAR Centers are important components of the United Nations Food and Agriculture Organization’s global system of conservation and use of PGRFA. They also play an important supportive role [...] Read more.

The international collections of plant genetic resources for food and agriculture (PGRFA) hosted by 11 CGIAR Centers are important components of the United Nations Food and Agriculture Organization’s global system of conservation and use of PGRFA. They also play an important supportive role in realizing Target 2.5 of the Sustainable Development Goals. This paper analyzes CGIAR genebanks’ trends in acquiring and distributing PGRFA over the last 35 years, with a particular focus on the last decade. The paper highlights a number of factors influencing the Centers’ acquisition of new PGRFA to include in the international collections, including increased capacity to analyze gaps in those collections and precisely target new collecting missions, availability of financial resources, and the state of international and national access and benefit-sharing laws and phytosanitary regulations. Factors contributing to Centers’ distributions of PGRFA included the extent of accession-level information, users’ capacity to identify the materials they want, and policies. The genebanks’ rates of both acquisition and distribution increased over the last decade. The paper ends on a cautionary note concerning the potential of unresolved tensions regarding access and benefit sharing and digital genomic sequence information to undermine international cooperation to conserve and use PGRFA. Full article

(This article belongs to the Special Issue Plant Biodiversity and Genetic Resources)

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25 pages, 2771 KiB

Open AccessEditor’s ChoiceReview

Review of the State of the Art of Deep Learning for Plant Diseases: A Broad Analysis and Discussion

by Reem Ibrahim Hasan, Suhaila Mohd Yusuf and Laith Alzubaidi

Plants 2020, 9(10), 1302; https://doi.org/10.3390/plants9101302 - 1 Oct 2020

Cited by 136 | Viewed by 12689

Abstract

Deep learning (DL) represents the golden era in the machine learning (ML) domain, and it has gradually become the leading approach in many fields. It is currently playing a vital role in the early detection and classification of plant diseases. The use of [...] Read more.

Deep learning (DL) represents the golden era in the machine learning (ML) domain, and it has gradually become the leading approach in many fields. It is currently playing a vital role in the early detection and classification of plant diseases. The use of ML techniques in this field is viewed as having brought considerable improvement in cultivation productivity sectors, particularly with the recent emergence of DL, which seems to have increased accuracy levels. Recently, many DL architectures have been implemented accompanying visualisation techniques that are essential for determining symptoms and classifying plant diseases. This review investigates and analyses the most recent methods, developed over three years leading up to 2020, for training, augmentation, feature fusion and extraction, recognising and counting crops, and detecting plant diseases, including how these methods can be harnessed to feed deep classifiers and their effects on classifier accuracy. Full article

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36 pages, 11967 KiB

Open AccessEditor’s ChoiceReview

Born to Eat Wild: An Integrated Conservation Approach to Secure Wild Food Plants for Food Security and Nutrition

by Teresa Borelli, Danny Hunter, Bronwen Powell, Tiziana Ulian, Efisio Mattana, Céline Termote, Lukas Pawera, Daniela Beltrame, Daniela Penafiel, Ayfer Tan, Mary Taylor and Johannes Engels

Plants 2020, 9(10), 1299; https://doi.org/10.3390/plants9101299 - 1 Oct 2020

Cited by 73 | Viewed by 10835

Abstract

Overlooked in national reports and in conservation programs, wild food plants (WFPs) have been a vital component of food and nutrition security for centuries. Recently, several countries have reported on the widespread and regular consumption of WFPs, particularly by rural and indigenous communities [...] Read more.

Overlooked in national reports and in conservation programs, wild food plants (WFPs) have been a vital component of food and nutrition security for centuries. Recently, several countries have reported on the widespread and regular consumption of WFPs, particularly by rural and indigenous communities but also in urban contexts. They are reported as critical for livelihood resilience and for providing essential micronutrients to people enduring food shortages or other emergency situations. However, threats derived from changes in land use and climate, overexploitation and urbanization are reducing the availability of these biological resources in the wild and contributing to the loss of traditional knowledge associated with their use. Meanwhile, few policy measures are in place explicitly targeting their conservation and sustainable use. This can be partially attributed to a lack of scientific evidence and awareness among policymakers and relevant stakeholders of the untapped potential of WFPs, accompanied by market and non-market barriers limiting their use. This paper reviews recent efforts being undertaken in several countries to build evidence of the importance of WFPs, while providing examples of cross-sectoral cooperation and multi-stakeholder approaches that are contributing to advance their conservation and sustainable use. An integrated conservation approach is proposed contributing to secure their availability for future generations. Full article

(This article belongs to the Special Issue Plant Biodiversity and Genetic Resources)

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24 pages, 2477 KiB

Open AccessEditor’s ChoiceArticle

Potential Effects of Essential Oils Extracted from Mediterranean Aromatic Plants on Target Weeds and Soil Microorganisms

by Amira Jouini, Mercedes Verdeguer, Samuele Pinton, Fabrizio Araniti, Eristanna Palazzolo, Luigi Badalucco and Vito Armando Laudicina

Plants 2020, 9(10), 1289; https://doi.org/10.3390/plants9101289 - 29 Sep 2020

Cited by 28 | Viewed by 4234

Abstract

Essential oils (EOs), extracted from aromatic plants, have been proposed as candidates to develop natural herbicides. This study aimed to evaluate the herbicidal potential of Thymbra capitata (L.) Cav., Mentha × piperita L. and Santolina chamaecyparissus L. essential oils (EOs) on Avena fatua [...] Read more.

Essential oils (EOs), extracted from aromatic plants, have been proposed as candidates to develop natural herbicides. This study aimed to evaluate the herbicidal potential of Thymbra capitata (L.) Cav., Mentha × piperita L. and Santolina chamaecyparissus L. essential oils (EOs) on Avena fatua L., Echinochloa crus-galli (L.) P. Beauv, Portulaca oleracea L. and Amaranthus retroflexus L. and their effects on soil microorganisms. A pot experiment was set up and three EOs at three doses were applied by irrigation. Efficacy and effects of EOs on weed growth were determined. Soil microbial biomass carbon and nitrogen, microbial respiration, and the main microbial groups were determined at days 7, 28 and 56. EOs demonstrated herbicidal activity, increasing their toxicity with the dose. T. capitata was the most effective against all weeds at the maximum dose. P. oleracea was the most resistant weed. Soil microorganisms, after a transient upheaval period induced by the addition of EOs, recovered their initial function and biomass. T. capitata EO at the highest dose did not allow soil microorganisms to recover their initial functionality. EOs exhibited great potential as natural herbicides but the optimum dose of application must be identified to control weeds and not negatively affect soil microorganisms. Full article

(This article belongs to the Special Issue Secondary Metabolites and Eco-friendly Techniques for Agricultural Weed/Pest Management)

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21 pages, 2543 KiB

Open AccessEditor’s ChoiceArticle

Challenges for Ex Situ Conservation of Wild Bananas: Seeds Collected in Papua New Guinea Have Variable Levels of Desiccation Tolerance

by Simon Kallow, Kevin Longin, Natalia Fanega Sleziak, Steven B. Janssens, Filip Vandelook, John Dickie, Rony Swennen, Janet Paofa, Sebastien Carpentier and Bart Panis

Plants 2020, 9(9), 1243; https://doi.org/10.3390/plants9091243 - 21 Sep 2020

Cited by 18 | Viewed by 6465

Abstract

Ex situ seed conservation of banana crop wild relatives (Musa spp. L.), is constrained by critical knowledge gaps in their storage and germination behaviour. Additionally, challenges in collecting seeds from wild populations impact the quality of seed collections. It is, therefore, crucial [...] Read more.

Ex situ seed conservation of banana crop wild relatives (Musa spp. L.), is constrained by critical knowledge gaps in their storage and germination behaviour. Additionally, challenges in collecting seeds from wild populations impact the quality of seed collections. It is, therefore, crucial to evaluate the viability of seeds from such collecting missions in order to improve the value of future seed collections. We evaluate the seed viability of 37 accessions of seven Musa species, collected from wild populations in Papua New Guinea, during two collecting missions. Seeds from one mission had already been stored in conventional storage (dried for four months at 15% relative humidity, 20 °C and stored for two months at 15% relative humdity, −20 °C), so a post-storage test was carried out. Seeds from the second mission were assessed freshly extracted and following desiccation. We used embryo rescue techniques to overcome the barrier of germinating in vivo Musa seeds. Seeds from the first mission had low viability (19 ± 27% mean and standard deviation) after storage for two months at 15% relative humidity and −20 °C. Musa balbisiana Colla seeds had significantly higher post-storage germination than other species (p < 0.01). Desiccation reduced germination of the seeds from the second collecting mission, from 84 ± 22% (at 16.7 ± 2.4% moisture content) to 36 ± 30% (at 2.4 ± 0.8% moisture content). There was considerable variation between and (to a lesser extent) within accessions, a proportion of individual seeds of all but one species (Musa ingens N.W.Simmonds) survived desiccation and sub-zero temperature storage. We identified that seeds from the basal end of the infructescence were less likely to be viable after storage (p < 0.001); and made morphological observations that identify seeds and infructescences with higher viability in relation to their developmental maturity. We highlight the need for research into seed eco-physiology of crop wild relatives in order to improve future collecting missions. Full article

(This article belongs to the Special Issue Plant Biodiversity and Genetic Resources)

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41 pages, 14693 KiB

Open AccessEditor’s ChoiceReview

Plants-Derived Biomolecules as Potent Antiviral Phytomedicines: New Insights on Ethnobotanical Evidences against Coronaviruses

by Arif Jamal Siddiqui, Corina Danciu, Syed Amir Ashraf, Afrasim Moin, Ritu Singh, Mousa Alreshidi, Mitesh Patel, Sadaf Jahan, Sanjeev Kumar, Mulfi I. M. Alkhinjar, Riadh Badraoui, Mejdi Snoussi and Mohd Adnan

Plants 2020, 9(9), 1244; https://doi.org/10.3390/plants9091244 - 21 Sep 2020

Cited by 49 | Viewed by 13167

Abstract

SARS-CoV-2 infection (COVID-19) is in focus over all known human diseases, because it is destroying the world economy and social life, with increased mortality rate each day. To date, there is no specific medicine or vaccine available against this pandemic disease. However, the [...] Read more.

SARS-CoV-2 infection (COVID-19) is in focus over all known human diseases, because it is destroying the world economy and social life, with increased mortality rate each day. To date, there is no specific medicine or vaccine available against this pandemic disease. However, the presence of medicinal plants and their bioactive molecules with antiviral properties might also be a successful strategy in order to develop therapeutic agents against SARS-CoV-2 infection. Thus, this review will summarize the available literature and other information/data sources related to antiviral medicinal plants, with possible ethnobotanical evidence in correlation with coronaviruses. The identification of novel antiviral compounds is of critical significance, and medicinal plant based natural compounds are a good source for such discoveries. In depth search and analysis revealed several medicinal plants with excellent efficacy against SARS-CoV-1 and MERS-CoV, which are well-known to act on ACE-2 receptor, 3CLpro and other viral protein targets. In this review, we have consolidated the data of several medicinal plants and their natural bioactive metabolites, which have promising antiviral activities against coronaviruses with detailed modes of action/mechanism. It is concluded that this review will be useful for researchers worldwide and highly recommended for the development of naturally safe and effective therapeutic drugs/agents against SARS-CoV-2 infection, which might be used in therapeutic protocols alone or in combination with chemically synthetized drugs. Full article

(This article belongs to the Special Issue Natural Compounds–Successful Solutions for the Medical Challenges of the 21st Century)

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14 pages, 868 KiB

Open AccessEditor’s ChoiceReview

Accelerating Tomato Breeding by Exploiting Genomic Selection Approaches

by Elisa Cappetta, Giuseppe Andolfo, Antonio Di Matteo, Amalia Barone, Luigi Frusciante and Maria Raffaella Ercolano

Plants 2020, 9(9), 1236; https://doi.org/10.3390/plants9091236 - 18 Sep 2020

Cited by 28 | Viewed by 9209

Abstract

Genomic selection (GS) is a predictive approach that was built up to increase the rate of genetic gain per unit of time and reduce the generation interval by utilizing genome-wide markers in breeding programs. It has emerged as a valuable method for improving [...] Read more.

Genomic selection (GS) is a predictive approach that was built up to increase the rate of genetic gain per unit of time and reduce the generation interval by utilizing genome-wide markers in breeding programs. It has emerged as a valuable method for improving complex traits that are controlled by many genes with small effects. GS enables the prediction of the breeding value of candidate genotypes for selection. In this work, we address important issues related to GS and its implementation in the plant context with special emphasis on tomato breeding. Genomic constraints and critical parameters affecting the accuracy of prediction such as the number of markers, statistical model, phenotyping and complexity of trait, training population size and composition should be carefully evaluated. The comparison of GS approaches for facilitating the selection of tomato superior genotypes during breeding programs is also discussed. GS applied to tomato breeding has already been shown to be feasible. We illustrated how GS can improve the rate of gain in elite line selection, and descendent and backcross schemes. The GS schemes have begun to be delineated and computer science can provide support for future selection strategies. A new promising breeding framework is beginning to emerge for optimizing tomato improvement procedures. Full article

(This article belongs to the Special Issue Molecular Breeding in Horticultural Plants)

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26 pages, 3359 KiB

Open AccessEditor’s ChoiceReview

Management of Infection by Parasitic Weeds: A Review

by Mónica Fernández-Aparicio, Philippe Delavault and Michael P. Timko

Plants 2020, 9(9), 1184; https://doi.org/10.3390/plants9091184 - 11 Sep 2020

Cited by 55 | Viewed by 8725

Abstract

Parasitic plants rely on neighboring host plants to complete their life cycle, forming vascular connections through which they withdraw needed nutritive resources. In natural ecosystems, parasitic plants form one component of the plant community and parasitism contributes to overall community balance. In contrast, [...] Read more.

Parasitic plants rely on neighboring host plants to complete their life cycle, forming vascular connections through which they withdraw needed nutritive resources. In natural ecosystems, parasitic plants form one component of the plant community and parasitism contributes to overall community balance. In contrast, when parasitic plants become established in low biodiversified agroecosystems, their persistence causes tremendous yield losses rendering agricultural lands uncultivable. The control of parasitic weeds is challenging because there are few sources of crop resistance and it is difficult to apply controlling methods selective enough to kill the weeds without damaging the crop to which they are physically and biochemically attached. The management of parasitic weeds is also hindered by their high fecundity, dispersal efficiency, persistent seedbank, and rapid responses to changes in agricultural practices, which allow them to adapt to new hosts and manifest increased aggressiveness against new resistant cultivars. New understanding of the physiological and molecular mechanisms behind the processes of germination and haustorium development, and behind the crop resistant response, in addition to the discovery of new targets for herbicides and bioherbicides will guide researchers on the design of modern agricultural strategies for more effective, durable, and health compatible parasitic weed control. Full article

(This article belongs to the Special Issue Parasitic Plants Management)

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21 pages, 1321 KiB

Open AccessEditor’s ChoiceArticle

Role of Organic Anions and Phosphatase Enzymes in Phosphorus Acquisition in the Rhizospheres of Legumes and Grasses Grown in a Low Phosphorus Pasture Soil

by Driss Touhami, Richard W. McDowell and Leo M. Condron

Plants 2020, 9(9), 1185; https://doi.org/10.3390/plants9091185 - 11 Sep 2020

Cited by 32 | Viewed by 5064

Abstract

Rhizosphere processes play a critical role in phosphorus (P) acquisition by plants and microbes, especially under P-limited conditions. Here, we investigated the impacts of nutrient addition and plant species on plant growth, rhizosphere processes, and soil P dynamics. In a glasshouse experiment, blue [...] Read more.

Rhizosphere processes play a critical role in phosphorus (P) acquisition by plants and microbes, especially under P-limited conditions. Here, we investigated the impacts of nutrient addition and plant species on plant growth, rhizosphere processes, and soil P dynamics. In a glasshouse experiment, blue lupin (Lupinus angustifolius), white clover (Trifolium repens L.), perennial ryegrass (Lolium perenne L.), and wheat (Triticum aestivum L.) were grown in a low-P pasture soil for 8 weeks with and without the single and combined addition of P (33 mg kg⁻¹) and nitrogen (200 mg kg⁻¹). Phosphorus addition increased plant biomass and total P content across plant species, as well as microbial biomass P in white clover and ryegrass. Alkaline phosphatase activity was higher for blue lupin. Legumes showed higher concentrations of organic anions compared to grasses. After P addition, the concentrations of organic anions increased by 11-,10-, 5-, and 2-fold in the rhizospheres of blue lupin, white clover, wheat, and ryegrass, respectively. Despite the differences in their chemical availability (as assessed by P fractionation), moderately labile inorganic P and stable organic P were the most depleted fractions by the four plant species. Inorganic P fractions were depleted similarly between the four plant species, while blue lupin exhibited a strong depletion of stable organic P. Our findings suggest that organic anions were not related to the acquisition of inorganic P for legumes and grasses. At the same time, alkaline phosphatase activity was associated with the mobilization of stable organic P for blue lupin. Full article

(This article belongs to the Special Issue Soil Fertility and Nutrient Cycling II)

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31 pages, 14054 KiB

Open AccessEditor’s ChoiceArticle

Three New Alien Taxa for Europe and a Chorological Update on the Alien Vascular Flora of Calabria (Southern Italy)

by Valentina Lucia Astrid Laface, Carmelo Maria Musarella, Ana Cano Ortiz, Ricardo Quinto Canas, Serafino Cannavò and Giovanni Spampinato

Plants 2020, 9(9), 1181; https://doi.org/10.3390/plants9091181 - 11 Sep 2020

Cited by 28 | Viewed by 4956

Abstract

Knowledge on alien species is needed nowadays to protect natural habitats and prevent ecological damage. The presence of new alien plant species in Italy is increasing every day. Calabria, its southernmost region, is not yet well known with regard to this aspect. Thanks [...] Read more.

Knowledge on alien species is needed nowadays to protect natural habitats and prevent ecological damage. The presence of new alien plant species in Italy is increasing every day. Calabria, its southernmost region, is not yet well known with regard to this aspect. Thanks to fieldwork, sampling, and observing many exotic plants in Calabria, here, we report new data on 34 alien taxa. In particular, we found three new taxa for Europe (Cascabela thevetia, Ipomoea setosa subsp. pavonii, and Tecoma stans), three new for Italy (Brugmansia aurea, Narcissus ‘Cotinga’, and Narcissus ‘Erlicheer’), one new one for the Italian Peninsula (Luffa aegyptiaca), and 21 new taxa for Calabria (Allium cepa, Asparagus setaceus, Bassia scoparia, Beta vulgaris subsp. vulgaris, Bidens formosa, Casuarina equisetifolia, Cedrus atlantica, Chlorophytum comosum, Cucurbita maxima subsp. maxima, Dolichandra unguis-cati, Fagopyrum esculentum, Freesia alba, Juglans regia, Kalanchoë delagoënsis, Passiflora caerulea, Portulaca grandiflora, Prunus armeniaca, Prunus dulcis, Solanum tuberosum, Tradescantia sillamontana, and Washingtonia filifera). Furthermore, we provide the first geolocalized record of Araujia sericifera, the confirmation of Oxalis stricta, and propose a change of status for four taxa (Cenchrus setaceus, Salpichroa origanifolia, Sesbania punicea, and Nothoscordum gracile) for Calabria. The updated knowledge on the presence of new alien species in Calabria, in Italy and in Europe could allow for the prevention of other new entries and to eliminate this potential ecological threat to natural habitats. Full article

(This article belongs to the Special Issue Threatened Vegetation and Environmental Management)

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19 pages, 2234 KiB

Open AccessEditor’s ChoiceReview

Transient Gene Expression is an Effective Experimental Tool for the Research into the Fine Mechanisms of Plant Gene Function: Advantages, Limitations, and Solutions

by Alexander A. Tyurin, Alexandra V. Suhorukova, Ksenia V. Kabardaeva and Irina V. Goldenkova-Pavlova

Plants 2020, 9(9), 1187; https://doi.org/10.3390/plants9091187 - 11 Sep 2020

Cited by 37 | Viewed by 7622

Abstract

A large data array on plant gene expression accumulated thanks to comparative omic studies directs the efforts of researchers to the specific or fine effects of the target gene functions and, as a consequence, elaboration of relatively simple and concurrently effective approaches allowing [...] Read more.

A large data array on plant gene expression accumulated thanks to comparative omic studies directs the efforts of researchers to the specific or fine effects of the target gene functions and, as a consequence, elaboration of relatively simple and concurrently effective approaches allowing for the insight into the physiological role of gene products. Numerous studies have convincingly demonstrated the efficacy of transient expression strategy for characterization of the plant gene functions. The review goals are (i) to consider the advantages and limitations of different plant systems and methods of transient expression used to find out the role of gene products; (ii) to summarize the current data on the use of the transient expression approaches for the insight into fine mechanisms underlying the gene function; and (iii) to outline the accomplishments in efficient transient expression of plant genes. In general, the review discusses the main and critical steps in each of the methods of transient gene expression in plants; areas of their application; main results obtained using plant objects; their contribution to our knowledge about the fine mechanisms of the plant gene functions underlying plant growth and development; and clarification of the mechanisms regulating complex metabolic pathways. Full article

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17 pages, 3218 KiB

Open AccessEditor’s ChoiceArticle

Enhanced Agronomic Efficiency Using a New Controlled-Released, Polymeric-Coated Nitrogen Fertilizer in Rice

by Ricardo Gil-Ortiz, Miguel Ángel Naranjo, Antonio Ruiz-Navarro, Sergio Atares, Carlos García, Lincoln Zotarelli, Alberto San Bautista and Oscar Vicente

Plants 2020, 9(9), 1183; https://doi.org/10.3390/plants9091183 - 11 Sep 2020

Cited by 38 | Viewed by 4840

Abstract

Fertilizer-use efficiency is one of the most critical concerns in rice cultivation to reduce N losses, increase yields, and improve crop management. The effects of a new polymeric-coated controlled-release fertilizer (CRF) were compared to those of other slow-release and traditional fertilizers in a [...] Read more.

Fertilizer-use efficiency is one of the most critical concerns in rice cultivation to reduce N losses, increase yields, and improve crop management. The effects of a new polymeric-coated controlled-release fertilizer (CRF) were compared to those of other slow-release and traditional fertilizers in a microscale experiment, which was carried out in cuvettes under partly controlled ambient conditions, and a large-scale field experiment. To evaluate the fertilizer’s efficiency, nitrogen and water-use efficiency were calculated using the measurement of different photosynthetic and crop yield parameters. Improved responses regarding some of the analyzed physiological and growth parameters were observed for those plants fertilized with the new CRF. In the microscale experiment, significantly increased yields (ca. 35%) were produced in the plants treated with CRF as compared to traditional fertilizer. These results were in accordance with ca. 24% significant increased levels of N in leaves of CRF-treated plants, besides increased P, Fe, Mn, and cytokinin contents. At the field scale, similar yields were obtained with the slow-release or traditional fertilizers and CRF at a 20% reduced N dose. The new controlled-release fertilizer is a urea-based fertilizer coated with lignosulfonates, which is cheaply produced from the waste of pulp and wood industries, containing humic acids as biostimulants. In conclusion, CRF is recommended to facilitate rice crop management and to reduce contamination, as it can be formulated with lower N doses and because it is ecological manufacturing. Full article

(This article belongs to the Special Issue Genetic Resources, Nitrogen Nutrition, and Stress Tolerance in Cereals)

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30 pages, 8578 KiB

Open AccessEditor’s ChoiceArticle

Plant Soft Rot Development and Regulation from the Viewpoint of Transcriptomic Profiling

by Ivan Tsers, Vladimir Gorshkov, Natalia Gogoleva, Olga Parfirova, Olga Petrova and Yuri Gogolev

Plants 2020, 9(9), 1176; https://doi.org/10.3390/plants9091176 - 10 Sep 2020

Cited by 20 | Viewed by 4019

Abstract

Soft rot caused by Pectobacterium species is a devastating plant disease poorly characterized in terms of host plant responses. In this study, changes in the transcriptome of tobacco plants after infection with Pectobacterium atrosepticum (Pba) were analyzed using RNA-Seq. To draw [...] Read more.

Soft rot caused by Pectobacterium species is a devastating plant disease poorly characterized in terms of host plant responses. In this study, changes in the transcriptome of tobacco plants after infection with Pectobacterium atrosepticum (Pba) were analyzed using RNA-Seq. To draw a comprehensive and nontrivially itemized picture of physiological events in Pba-infected plants and to reveal novel potential molecular “players” in plant–Pba interactions, an original functional gene classification was performed. The classifications present in various databases were merged, enriched by “missed” genes, and divided into subcategories. Particular changes in plant cell wall-related processes, perturbations in hormonal and other regulatory systems, and alterations in primary, secondary, and redox metabolism were elucidated in terms of gene expression. Special attention was paid to the prediction of transcription factors (TFs) involved in the disease’s development. Herewith, gene expression was analyzed within the predicted TF regulons assembled at the whole-genome level based on the presence of particular cis-regulatory elements (CREs) in gene promoters. Several TFs, whose regulons were enriched by differentially expressed genes, were considered to be potential master regulators of Pba-induced plant responses. Differential regulation of genes belonging to a particular multigene family and encoding cognate proteins was explained by the presence/absence of the particular CRE in gene promoters. Full article

(This article belongs to the Special Issue Omics in Plant-Pathogen Interaction)

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23 pages, 5043 KiB

Open AccessEditor’s ChoiceArticle

Variations of Essential Oil Constituents in Oregano (Origanum vulgare subsp. viridulum (= O. heracleoticum) over Cultivation Cycles

by Edoardo Napoli, Antonio Giovino, Alessandra Carrubba, Vandana How Yuen Siong, Carmelo Rinoldo, Onofrio Nina and Giuseppe Ruberto

Plants 2020, 9(9), 1174; https://doi.org/10.3390/plants9091174 - 10 Sep 2020

Cited by 26 | Viewed by 3967

Abstract

Oregano is—probably—the most appreciated and widespread aromatic plant in Sicily. With the aim of evaluating the modifications of oregano’s essential oil composition over time, between 2013 and 2015 six weekly samplings of three different oregano plantations were carried out, from the beginning of [...] Read more.

Oregano is—probably—the most appreciated and widespread aromatic plant in Sicily. With the aim of evaluating the modifications of oregano’s essential oil composition over time, between 2013 and 2015 six weekly samplings of three different oregano plantations were carried out, from the beginning of flowering (early May) until the traditional harvest moment (end of June). Samples were hydrodistilled and the obtained essential oils (EOs) were evaluated by means of a combination of GC–FID and GC–MS. The Origanum plants under study were demonstrated to belong to the high-yielding, thymol-type biotypes, with thymol, γ-terpinene and p-cymene as three main components, among the total of about 50 of the evaluated EOs. In each location, EO yields were found to increase throughout survey dates. Significant variations were found in many EO components, both across years and throughout harvest dates within locations. The choice of the harvest moment was confirmed to be crucial in assessing quality aspects of oregano. Full article

(This article belongs to the Special Issue Plant Volatiles: A Goldmine Not Fully Explored)

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14 pages, 1171 KiB

Open AccessEditor’s ChoiceArticle

Longer Photoperiods with the Same Daily Light Integral Increase Daily Electron Transport through Photosystem II in Lettuce

by Claudia Elkins and Marc W. van Iersel

Plants 2020, 9(9), 1172; https://doi.org/10.3390/plants9091172 - 10 Sep 2020

Cited by 34 | Viewed by 5240

Abstract

Controlled environment crop production recommendations often use the daily light integral (DLI) to quantify the light requirements of specific crops. Sole-source electric lighting, used in plant factories, and supplemental electric lighting, used in greenhouses, may be required to attain a specific DLI. Electric [...] Read more.

Controlled environment crop production recommendations often use the daily light integral (DLI) to quantify the light requirements of specific crops. Sole-source electric lighting, used in plant factories, and supplemental electric lighting, used in greenhouses, may be required to attain a specific DLI. Electric lighting is wasteful if not provided in a way that promotes efficient photochemistry. The quantum yield of photosystem II (Φ_PSII), the fraction of absorbed light used for photochemistry, decreases with increasing photosynthetic photon flux density (PPFD). Thus, we hypothesized that the daily photochemical integral (DPI), the total electron transport through photosystem II (PSII) integrated over 24 h, would increase if the same DLI was provided at a lower PPFD over a longer photoperiod. To test this, Φ_PSII and the electron transport rate (ETR) of lettuce (Lactuca sativa ‘Green Towers’) were measured in a growth chamber at DLIs of 15 and 20 mol m⁻² d⁻¹ over photoperiods ranging from 7 to 22 h. This resulted in PPFDs of 189 to 794 μmol m⁻² s⁻¹. The Φ_PSII decreased from 0.67 to 0.28 and ETR increased from 55 to 99 μmol m⁻² s⁻¹ as PPFD increased from 189 to 794 μmol m⁻² s⁻¹. The DPI increased linearly as the photoperiod increased, but the magnitude of this response depended on DLI. With a 7-h photoperiod, the DPI was ≈2.7 mol m⁻² d⁻¹, regardless of DLI. However, with a 22-h photoperiod, the DPI was 4.54 mol m⁻² d⁻¹ with a DLI of 15 mol m⁻² d⁻¹ and 5.78 mol m⁻² d⁻¹ with a DLI of 20 mol m⁻² d⁻¹. Our hypothesis that DPI can be increased by providing the same DLI over longer photoperiods was confirmed. Full article

(This article belongs to the Special Issue Applications and Advances in Artificial Light for Horticulture and Crop Production)

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14 pages, 17337 KiB

Open AccessEditor’s ChoiceArticle

Gene Expression Profiles and Flavonoid Accumulation during Salt Stress in Ginkgo biloba Seedlings

by Ningtao Xu, Sian Liu, Zhaogeng Lu, Siyu Pang, Lu Wang, Li Wang and Weixing Li

Plants 2020, 9(9), 1162; https://doi.org/10.3390/plants9091162 - 8 Sep 2020

Cited by 66 | Viewed by 4297

Abstract

Ginkgo biloba is an economically valuable tree, as a variety of flavonoid compounds are produced by the leaves of its seedlings. Although soil salinity is a serious threat to agricultural productivity worldwide, the effect of salt stress on G. biloba seedlings remains unclear. [...] Read more.

Ginkgo biloba is an economically valuable tree, as a variety of flavonoid compounds are produced by the leaves of its seedlings. Although soil salinity is a serious threat to agricultural productivity worldwide, the effect of salt stress on G. biloba seedlings remains unclear. In this study, we found that under high NaCl concentrations (200 and 300 mmol/L), seedling growth was inhibited and the water content, chlorophyll, and peroxidase (POD) enzyme activity were significantly decreased in the leaves, whereas the soluble protein and proline levels increased significantly. However, at low NaCl concentrations (50 and 100 mmol/L), the seedlings grew normally because of the regulation of catalase (CAT) and POD enzyme activities. To elucidate the molecular mechanisms behind G. biloba salt tolerance, we examined the transcriptome of G. biloba seedlings treated with 100 mmol/L NaCl. Twelve differentially expressed genes (DEGs) were found to be involved in ion osmotic potential signal transduction and amplification, including two ABA signaling genes, five CDPK/CIPK genes, and five mitogen-activated protein kinase (MAPK) signaling genes. We also found that NAC transcription factors may be involved in the salt stress response; these included positive regulators (Gb_12203, Gb_27819, Gb_37720, and Gb_41540) and negative regulators (Gb_32549, Gb_35048, and Gb_37444). Importantly, treatment with 100 mmol/L NaCl can significantly improve flavonoid and flavonol glycoside biosynthesis. Simultaneously, the expression of flavonoid biosynthesis-related genes, including PAL (Gb_10949, Gb_21115) and FLS (Gb_00285, Gb_14024, and Gb_14029), was significantly upregulated. Based on these results, we reveal that G. biloba seedlings can tolerate low-level soil salinity stress through the regulation of different kinds of genes and transcriptome factors, especially flavonoid biosynthesis, which is improved to respond to environmental stress. Full article

(This article belongs to the Special Issue The Impacts of Abiotic Stresses on Plant Development)

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17 pages, 7395 KiB

Open AccessEditor’s ChoiceArticle

Leaf Soluble Sugars and Free Amino Acids as Important Components of Abscisic Acid—Mediated Drought Response in Tomato

by Bojana Živanović, Sonja Milić Komić, Tomislav Tosti, Marija Vidović, Ljiljana Prokić and Sonja Veljović Jovanović

Plants 2020, 9(9), 1147; https://doi.org/10.3390/plants9091147 - 4 Sep 2020

Cited by 46 | Viewed by 5910

Abstract

Water deficit has a global impact on plant growth and crop yield. Climate changes are going to increase the intensity, duration and frequency of severe droughts, particularly in southern and south-eastern Europe, elevating the water scarcity issues. We aimed to assess the contribution [...] Read more.

Water deficit has a global impact on plant growth and crop yield. Climate changes are going to increase the intensity, duration and frequency of severe droughts, particularly in southern and south-eastern Europe, elevating the water scarcity issues. We aimed to assess the contribution of endogenous abscisic acid (ABA) in the protective mechanisms against water deficit, including stomatal conductance, relative water potential and the accumulation of osmoprotectants, as well as on growth parameters. To achieve that, we used a suitable model system, ABA-deficient tomato mutant, flacca and its parental line. Flacca mutant exhibited constitutively higher levels of soluble sugars (e.g., galactose, arabinose, sorbitol) and free amino acids (AAs) compared with the wild type (WT). Water deficit provoked the strong accumulation of proline in both genotypes, and total soluble sugars only in flacca. Upon re-watering, these osmolytes returned to the initial levels in both genotypes. Our results indicate that flacca compensated higher stomatal conductance with a higher constitutive level of free sugars and AAs. Additionally, we suggest that the accumulation of AAs, particularly proline and its precursors and specific branched-chain AAs in both, glucose and sucrose in flacca, and sorbitol in WT, could contribute to maintaining growth rate during water deficit and recovery in both tomato genotypes. Full article

(This article belongs to the Section Plant Response to Abiotic Stress and Climate Change)

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14 pages, 988 KiB

Open AccessFeature PaperEditor’s ChoiceReview

Hydrogenases and the Role of Molecular Hydrogen in Plants

by Grace Russell, Faisal Zulfiqar and John T. Hancock

Plants 2020, 9(9), 1136; https://doi.org/10.3390/plants9091136 - 2 Sep 2020

Cited by 23 | Viewed by 5560

Abstract

Molecular hydrogen (H₂) has been suggested to be a beneficial treatment for a range of species, from humans to plants. Hydrogenases catalyze the reversible oxidation of H₂, and are found in many organisms, including plants. One of the cellular [...] Read more.

Molecular hydrogen (H₂) has been suggested to be a beneficial treatment for a range of species, from humans to plants. Hydrogenases catalyze the reversible oxidation of H₂, and are found in many organisms, including plants. One of the cellular effects of H₂ is the selective removal of reactive oxygen species (ROS) and reactive nitrogen species (RNS), specifically hydroxyl radicals and peroxynitrite. Therefore, the function of hydrogenases and the action of H₂ needs to be reviewed in the context of the signalling roles of a range of redox active compounds. Enzymes can be controlled by the covalent modification of thiol groups, and although motifs targeted by nitric oxide (NO) can be predicted in hydrogenases sequences it is likely that the metal prosthetic groups are the target of inhibition. Here, a selection of hydrogenases, and the possibility of their control by molecules involved in redox signalling are investigated using a bioinformatics approach. Methods of treating plants with H₂ along with the role of H₂ in plants is also briefly reviewed. It is clear that studies report significant effects of H₂ on plants, improving growth and stress responses, and therefore future work needs to focus on the molecular mechanisms involved. Full article

(This article belongs to the Collection Feature Papers in Plant Physiology and Metabolism)

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9 pages, 792 KiB

Open AccessEditor’s ChoiceReview

Roles of Aquaporins in Plant-Pathogen Interaction

by Guangjin Li, Tong Chen, Zhanquan Zhang, Boqiang Li and Shiping Tian

Plants 2020, 9(9), 1134; https://doi.org/10.3390/plants9091134 - 1 Sep 2020

Cited by 28 | Viewed by 7277

Abstract

Aquaporins (AQPs) are a class of small, membrane channel proteins present in a wide range of organisms. In addition to water, AQPs can facilitate the efficient and selective flux of various small solutes involved in numerous essential processes across membranes. A growing body [...] Read more.

Aquaporins (AQPs) are a class of small, membrane channel proteins present in a wide range of organisms. In addition to water, AQPs can facilitate the efficient and selective flux of various small solutes involved in numerous essential processes across membranes. A growing body of evidence now shows that AQPs are important regulators of plant-pathogen interaction, which ultimately lead to either plant immunity or pathogen pathogenicity. In plants, AQPs can mediate H₂O₂ transport across plasma membranes (PMs) and contribute to the activation of plant defenses by inducing pathogen-associated molecular pattern (PAMP)-triggered immunity and systemic acquired resistance (SAR), followed by downstream defense reactions. This involves the activation of conserved mitogen-activated protein kinase (MAPK) signaling cascades, the production of callose, the activation of NPR1 and PR genes, as well as the opening and closing of stomata. On the other hand, pathogens utilize aquaporins to mediate reactive oxygen species (ROS) signaling and regulate their normal growth, development, secondary or specialized metabolite production and pathogenicity. This review focuses on the roles of AQPs in plant immunity, pathogenicity, and communications during plant-pathogen interaction. Full article

(This article belongs to the Special Issue Plant Aquaporins)

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