Plants

Research

14 pages, 3409 KiB

Open AccessArticle

Iron-Sulfur Cluster Complex Assembly in the Mitochondria of Arabidopsis thaliana

by Alejandro M. Armas, Manuel Balparda, Agustina Terenzi, Maria V. Busi, Maria A. Pagani and Diego F. Gomez-Casati

Plants 2020, 9(9), 1171; https://doi.org/10.3390/plants9091171 - 9 Sep 2020

Cited by 8 | Viewed by 3224

Abstract

In plants, the cysteine desulfurase (AtNFS1) and frataxin (AtFH) are involved in the formation of Fe-S groups in mitochondria, specifically, in Fe and sulfur loading onto scaffold proteins, and the subsequent formation of the mature Fe-S cluster. We found that the small mitochondrial [...] Read more.

In plants, the cysteine desulfurase (AtNFS1) and frataxin (AtFH) are involved in the formation of Fe-S groups in mitochondria, specifically, in Fe and sulfur loading onto scaffold proteins, and the subsequent formation of the mature Fe-S cluster. We found that the small mitochondrial chaperone, AtISD11, and AtFH are positive regulators for AtNFS1 activity in Arabidopsis. Moreover, when the three proteins were incubated together, a stronger attenuation of the Fenton reaction was observed compared to that observed with AtFH alone. Using pull-down assays, we found that these three proteins physically interact, and sequence alignment and docking studies showed that several amino acid residues reported as critical for the interaction of their human homologous are conserved. Our results suggest that AtFH, AtNFS1 and AtISD11 form a multiprotein complex that could be involved in different stages of the iron–sulfur cluster (ISC) pathway in plant mitochondria. Full article

(This article belongs to the Special Issue 2019 Feature Papers by Plants’ Editorial Board Members)

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10 pages, 1374 KiB

Open AccessArticle

Genetic Architecture of Cereal Leaf Beetle Resistance in Wheat

by Tobias Würschum, Willmar L. Leiser, Simon M. Langer, Matthew R. Tucker and Thomas Miedaner

Plants 2020, 9(9), 1117; https://doi.org/10.3390/plants9091117 - 28 Aug 2020

Cited by 3 | Viewed by 2622

Abstract

Wheat production can be severely damaged by endemic and invasive insect pests. Here, we investigated resistance to cereal leaf beetle in a panel of 876 winter wheat cultivars, and dissected the genetic architecture underlying this insect resistance by association mapping. We observed an [...] Read more.

Wheat production can be severely damaged by endemic and invasive insect pests. Here, we investigated resistance to cereal leaf beetle in a panel of 876 winter wheat cultivars, and dissected the genetic architecture underlying this insect resistance by association mapping. We observed an effect of heading date on cereal leaf beetle infestation, with earlier heading cultivars being more heavily infested. Flag leaf glaucousness was also found to be correlated with resistance. In line with the strong effect of heading time, we identified Ppd-D1 as a major quantitative trait locus (QTL), explaining 35% of the genotypic variance of cereal leaf beetle resistance. The other identified putative QTL explained much less of the genotypic variance, suggesting a genetic architecture with many small-effect QTL, which was corroborated by a genomic prediction approach. Collectively, our results add to our understanding of the genetic control underlying insect resistances in small-grain cereals. Full article

(This article belongs to the Special Issue 2019 Feature Papers by Plants’ Editorial Board Members)

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17 pages, 972 KiB

Open AccessArticle

Development of High-Density Genetic Linkage Maps and Identification of Loci for Chestnut Gall Wasp Resistance in Castanea spp.

by Daniela Torello Marinoni, Sogo Nishio, Nadia Valentini, Kenta Shirasawa, Alberto Acquadro, Ezio Portis, Alberto Alma, Aziz Akkak, Vera Pavese, Emile Cavalet-Giorsa and Roberto Botta

Plants 2020, 9(8), 1048; https://doi.org/10.3390/plants9081048 - 18 Aug 2020

Cited by 15 | Viewed by 3667

Abstract

Castanea sativa is an important multipurpose species in Europe for nut and timber production as well as for its role in the landscape and in the forest ecosystem. This species has low tolerance to chestnut gall wasp (Dryocosmus kuriphilus Yasumatsu), which is [...] Read more.

Castanea sativa is an important multipurpose species in Europe for nut and timber production as well as for its role in the landscape and in the forest ecosystem. This species has low tolerance to chestnut gall wasp (Dryocosmus kuriphilus Yasumatsu), which is a pest that was accidentally introduced into Europe in early 2000 and devastated forest and orchard trees. Resistance to the gall wasp was found in the hybrid cultivar ‘Bouche de Bétizac’ (C. sativa × C. crenata) and studied by developing genetic linkage maps using a population derived from a cross between ‘Bouche de Bétizac’ and the susceptible cultivar ‘Madonna’ (C. sativa). The high-density genetic maps were constructed using double-digest restriction site-associated DNA-seq and simple sequence repeat markers. The map of ‘Bouche de Bétizac’ consisted of 1459 loci and spanned 809.6 cM; the map of ‘Madonna’ consisted of 1089 loci and spanned 753.3 cM. In both maps, 12 linkage groups were identified. A single major QTL was recognized on the ‘Bouche de Bétizac’ map, explaining up to 67–69% of the phenotypic variance of the resistance trait (Rdk1). The Rdk1 quantitative trait loci (QTL) region included 11 scaffolds and two candidate genes putatively involved in the resistance response were identified. This study will contribute to C. sativa breeding programs and to the study of Rdk1 genes. Full article

(This article belongs to the Special Issue 2019 Feature Papers by Plants’ Editorial Board Members)

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18 pages, 6785 KiB

Open AccessArticle

Arbuscular Mycorrhizal Symbiosis Enhances Photosynthesis in the Medicinal Herb Salvia fruticosa by Improving Photosystem II Photochemistry

by Michael Moustakas, Gülriz Bayçu, Ilektra Sperdouli, Hilal Eroğlu and Eleftherios P. Eleftheriou

Plants 2020, 9(8), 962; https://doi.org/10.3390/plants9080962 - 30 Jul 2020

Cited by 46 | Viewed by 4767

Abstract

We investigated the influence of Salvia fruticosa colonization by the arbuscular mycorrhizal fungi (AMF) Rhizophagus irregularis on photosynthetic function by using chlorophyll fluorescence imaging analysis to evaluate the light energy use in photosystem II (PSII) of inoculated and non-inoculated plants. We observed that [...] Read more.

We investigated the influence of Salvia fruticosa colonization by the arbuscular mycorrhizal fungi (AMF) Rhizophagus irregularis on photosynthetic function by using chlorophyll fluorescence imaging analysis to evaluate the light energy use in photosystem II (PSII) of inoculated and non-inoculated plants. We observed that inoculated plants used significantly higher absorbed energy in photochemistry (Φ_PSII) than non-inoculated and exhibited significant lower excess excitation energy (EXC). However, the increased Φ_PSII in inoculated plants did not result in a reduced non-regulated energy loss in PSII (Φ_NO), suggesting the same singlet oxygen (¹O₂) formation between inoculated and non-inoculated plants. The increased Φ_PSII in inoculated plants was due to an increased efficiency of open PSII centers to utilize the absorbed light (Fv’/Fm’) due to a decreased non-photochemical quenching (NPQ) since there was no difference in the fraction of open reaction centers (q_p). The decreased NPQ in inoculated plants resulted in an increased electron-transport rate (ETR) compared to non-inoculated. Yet, inoculated plants exhibited a higher efficiency of the water-splitting complex on the donor side of PSII as revealed by the increased Fv/Fo ratio. A spatial heterogeneity between the leaf tip and the leaf base for the parameters Φ_PSII and Φ_NPQ was observed in both inoculated and non-inoculated plants, reflecting different developmental zones. Overall, our findings suggest that the increased ETR of inoculated S. fruticosa contributes to increased photosynthetic performance, providing growth advantages to inoculated plants by increasing their aboveground biomass, mainly by increasing leaf biomass. Full article

(This article belongs to the Special Issue 2019 Feature Papers by Plants’ Editorial Board Members)

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23 pages, 5201 KiB

Open AccessArticle

Exploring Mechanisms of Quantitative Resistance to Leptosphaeria maculans (Blackleg) in the Cotyledons of Canola (Brassica napus) Based on Transcriptomic and Microscopic Analyses

by Michelle Hubbard, Chun Zhai and Gary Peng

Plants 2020, 9(7), 864; https://doi.org/10.3390/plants9070864 - 8 Jul 2020

Cited by 8 | Viewed by 3309

Abstract

Using resistant cultivars is a common approach to managing blackleg of canola/rapeseed caused by Leptosphaeria maculans (Lm). Quantitative resistance (QR), as opposed to major-gene resistance, is of interest because it is generally more durable, due to its multi-genetic basis. However, the [...] Read more.

Using resistant cultivars is a common approach to managing blackleg of canola/rapeseed caused by Leptosphaeria maculans (Lm). Quantitative resistance (QR), as opposed to major-gene resistance, is of interest because it is generally more durable, due to its multi-genetic basis. However, the mechanisms and genes underlying QR are mostly unknown. In this study, potential QR modes of action in “74-44 BL” was explored. This Canadian canola cultivar showed moderate but consistent race-nonspecific resistance at the cotyledon and adult-plant stages. A susceptible cultivar, “Westar”, was used as a control. After inoculation, the lesions developed more slowly on the cotyledons of 74-44 BL than those of Westar. We used RNA sequencing (-RNA-seq) to identify genes and their functions, putatively related to this resistance, and found that genes involved in programmed cell death (PCD), reactive oxygen species (ROS), signal transduction or intracellular endomembrane transport were most differentially expressed. ROS production was assessed in relation to Lm hyphal growth and lesion size; it occurred beyond the tissue colonized by Lm in 74-44 BL and appeared to trigger rapid cell death, limiting cotyledon colonization by Lm. In contrast, Lm grew more rapidly in Westar, often catching up with the ring of ROS and surpassing lesion boundaries. It appears that QR in 74-44 BL cotyledons is associated with limited colonization by Lm possibly mediated via ROS. The RNA-seq data also showed a link between ROS, signal transduction, and endomembrane vesicle trafficking, as well as PCD in the resistance. These results provide a starting point for a better understanding of the mechanisms behind QR against Lm in canola. Full article

(This article belongs to the Special Issue 2019 Feature Papers by Plants’ Editorial Board Members)

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15 pages, 547 KiB

Open AccessArticle

Elemental Composition and Some Nutritional Parameters of Sweet Pepper from Organic and Conventional Agriculture

by Rosa Guilherme, Fernando Reboredo, Mauro Guerra, Sandrine Ressurreição and Nuno Alvarenga

Plants 2020, 9(7), 863; https://doi.org/10.3390/plants9070863 - 8 Jul 2020

Cited by 20 | Viewed by 4476

Abstract

The increasing demand of organic agriculture (OA) is based on the consumer’s belief that organic agricultural products are healthier, tastier and more nutritious. The effect of OA and conventional agriculture (CA) methods on the elemental compositions of green and red sweet peppers were [...] Read more.

The increasing demand of organic agriculture (OA) is based on the consumer’s belief that organic agricultural products are healthier, tastier and more nutritious. The effect of OA and conventional agriculture (CA) methods on the elemental compositions of green and red sweet peppers were studied. The highest concentrations of Ca, Cu, K and P occur in peppers from OA in both states of ripeness, with emphasis on Ca and K contents. Furthermore, the principal component analysis (PCA), points out to a clear separation, regarding concentrations, between peppers from OA and CA. The average fruit weight is higher in OA, 141 g versus 112 g in CA. Regarding productivity, CA reaches a value of 30.1 t/ha, 7% higher than the value observed for OA, i.e., 28 t/ha. Peppers from CA, exhibited greater protein content than those which originated from OA, regardless of the ripening stage, but not more ashes. Regarding nutritional ratios, the ripening stage and the production mode, can be important for an adequate choice regarding a more balanced Ca/P ratio, and the studied variety contained high Ca values ranging between 1009 and 1930 mg.kg⁻¹. The PCA analysis also revealed that Mn and Fe are inversely correlated, confirming the importance of the Mn/Fe ratio evaluation in nutritional studies. Full article

(This article belongs to the Special Issue 2019 Feature Papers by Plants’ Editorial Board Members)

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9 pages, 1804 KiB

Open AccessCommunication

Discovery of Dihydrophaseic Acid Glucosides from the Florets of Carthamus tinctorius

by Su Cheol Baek, Bum Soo Lee, Sang Ah Yi, Jae Sik Yu, Jaecheol Lee, Yoon-Joo Ko, Changhyun Pang and Ki Hyun Kim

Plants 2020, 9(7), 858; https://doi.org/10.3390/plants9070858 - 7 Jul 2020

Cited by 8 | Viewed by 3251

Abstract

Carthamus tinctorius L. (Compositae; safflower or Hong Hua) has been used in Korean traditional medicine for maintaining the homeostasis of body circulation. Phytochemical investigation was performed on the florets of C. tinctorius by liquid chromatography–mass spectrometry (LC/MS), which afforded two dihydrophaseic acid glucosides [...] Read more.

Carthamus tinctorius L. (Compositae; safflower or Hong Hua) has been used in Korean traditional medicine for maintaining the homeostasis of body circulation. Phytochemical investigation was performed on the florets of C. tinctorius by liquid chromatography–mass spectrometry (LC/MS), which afforded two dihydrophaseic acid glucosides (1 and 2). Isolated compounds were structurally confirmed using a combination of spectroscopic methods including 1D and 2D nuclear magnetic resonance and high-resolution electrospray ionization mass spectroscopy. Their absolute configurations were established by quantum chemical electronic circular dichroism calculations and enzymatic hydrolysis. The anti-adipogenesis activity of the isolated compounds was evaluated using 3T3-L1 preadipocytes. Treatment with the dihydrophaseic acid glucoside (1) during adipocyte differentiation prevented the accumulation of lipid droplets and reduced the expression of adipogenic genes, Fabp4 and Adipsin. However, compound 2 did not affect adipogenesis. Our study yielded a dihydrophaseic acid glucoside derived from C. tinctorius, which has potential advantages for treating obesity. Full article

(This article belongs to the Special Issue 2019 Feature Papers by Plants’ Editorial Board Members)

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12 pages, 2821 KiB

Open AccessArticle

Indications for a Central Role of Hexokinase Activity in Natural Variation of Heat Acclimation in Arabidopsis thaliana

by Vasil Atanasov, Lisa Fürtauer and Thomas Nägele

Plants 2020, 9(7), 819; https://doi.org/10.3390/plants9070819 - 29 Jun 2020

Cited by 8 | Viewed by 3167

Abstract

Diurnal and seasonal changes of abiotic environmental factors shape plant performance and distribution. Changes of growth temperature and light intensity may vary significantly on a diurnal, but also on a weekly or seasonal scale. Hence, acclimation to a changing temperature and light regime [...] Read more.

Diurnal and seasonal changes of abiotic environmental factors shape plant performance and distribution. Changes of growth temperature and light intensity may vary significantly on a diurnal, but also on a weekly or seasonal scale. Hence, acclimation to a changing temperature and light regime is essential for plant survival and propagation. In the present study, we analyzed photosynthetic CO₂ assimilation and metabolic regulation of the central carbohydrate metabolism in two natural accessions of Arabidopsis thaliana that originate from north western Russia and south Italy during exposure to heat and a combination of heat and high light. Our findings indicate that it is hardly possible to predict photosynthetic capacities under combined stress from single stress experiments. Further, capacities of hexose phosphorylation were found to be significantly lower in the Italian than in the Russian accession, which could explain an inverted sucrose-to-hexose ratio. Together with the finding of significantly stronger accumulation of anthocyanins under heat/high light, these observations indicate a central role of hexokinase activity in the stabilization of photosynthesis and carbohydrate metabolism during environmental changes. Full article

(This article belongs to the Special Issue 2019 Feature Papers by Plants’ Editorial Board Members)

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11 pages, 964 KiB

Open AccessArticle

Nanofibrillation is an Effective Method to Produce Chitin Derivatives for Induction of Plant Responses in Soybean

by Hironori Kaminaka, Chihiro Miura, Yukiko Isowa, Takaya Tominaga, Mamu Gonnami, Mayumi Egusa and Shinsuke Ifuku

Plants 2020, 9(7), 810; https://doi.org/10.3390/plants9070810 - 28 Jun 2020

Cited by 5 | Viewed by 2868

Abstract

Chitin, an N-acetylglucosamine polymer, is well-known to have unique biological functions, such as growth promotion and disease resistance induction in plants. Chitin has been expectedly used for improving crop yield using its functions; however, chitin derivatives, such as chitin oligosaccharide (CO) and [...] Read more.

Chitin, an N-acetylglucosamine polymer, is well-known to have unique biological functions, such as growth promotion and disease resistance induction in plants. Chitin has been expectedly used for improving crop yield using its functions; however, chitin derivatives, such as chitin oligosaccharide (CO) and chitosan, are widely used instead since chitin is difficult to handle because of its insolubility. Chitin nanofiber (CNF), produced from chitin through nanofibrillation, retains its polymeric structure and can be dispersed uniformly even in water. Here, the effects of CO and CNF on plant responses were directly compared in soybeans (Glycine max) to define the most effective method to produce chitin derivatives for plant response induction. The growth promotion of aerial parts was observed only in CNF-treated plants. The transcriptome analysis showed that the number of differentially expressed genes (DEGs) in CNF-treated soybeans was higher than in CO-treated soybeans. Notably, the expression patterns of DEGs were mostly similar but were strongly induced by CNF treatment as compared with the CO group. These results reveal that CNF can induce stronger plant response to chitin than CO in soybeans, suggesting nanofibrillation, rather than oligomerization, as a more effective method to produce chitin derivatives for plant response induction. Full article

(This article belongs to the Special Issue 2019 Feature Papers by Plants’ Editorial Board Members)

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12 pages, 1784 KiB

Open AccessArticle

Comparative Functional Analysis of Class II Potassium Transporters, SvHKT2;1, SvHKT2;2, and HvHKT2;1, on Ionic Transport and Salt Tolerance in Transgenic Arabidopsis

by Yuichi Tada and Aki Ohnuma

Plants 2020, 9(6), 786; https://doi.org/10.3390/plants9060786 - 23 Jun 2020

Cited by 11 | Viewed by 3541

Abstract

Class II high-affinity potassium transporters (HKT2s) mediate Na⁺–K⁺ cotransport and Na⁺/K⁺ homeostasis under K⁺-starved or saline conditions. Their functions have been studied in yeast and X. laevis oocytes; however, little is known about their respective [...] Read more.

Class II high-affinity potassium transporters (HKT2s) mediate Na⁺–K⁺ cotransport and Na⁺/K⁺ homeostasis under K⁺-starved or saline conditions. Their functions have been studied in yeast and X. laevis oocytes; however, little is known about their respective properties in plant cells. In this study, we characterized the Na⁺ and K⁺ transport properties of SvHKT2;1, SvHKT2;2 and HvHKT2;1 in Arabidopsis under different ionic conditions. The differences were detected in shoot K⁺ accumulation and root K⁺ uptake under salt stress conditions, K⁺ accumulation in roots and phloem sap under K⁺-starved conditions, and shoot and root Na⁺ accumulation under K⁺-starved conditions among the HKT2s transgenic lines and WT plants. These results indicate the diverse ionic transport properties of these HKT2s in plant cells, which could not be detected using yeast or X. laevis oocytes. Furthermore, Arabidopsis expressing HKT2s showed reduced salt tolerance, while over-expression of HvHKT2;1 in barley, which has the ability to sequestrate Na⁺, showed enhanced salt tolerance by accumulating Na⁺ in the shoots. These results suggest that the coordinated enhancement of Na⁺ accumulation and sequestration mechanisms in shoots could be a promising strategy to confer salt tolerance to glycophytes. Full article

(This article belongs to the Special Issue 2019 Feature Papers by Plants’ Editorial Board Members)

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24 pages, 995 KiB

Open AccessFeature PaperArticle

Local Factors Rather than the Landscape Context Explain Species Richness and Functional Trait Diversity and Responses of Plant Assemblages of Mediterranean Cereal Field Margins

by Yesica Pallavicini, Fernando Bastida, Eva Hernández-Plaza, Sandrine Petit, Jordi Izquierdo and Jose L. Gonzalez-Andujar

Plants 2020, 9(6), 778; https://doi.org/10.3390/plants9060778 - 22 Jun 2020

Cited by 5 | Viewed by 2938

Abstract

Arable field margins are valuable habitats providing a wide range of ecosystem services in rural landscapes. Agricultural intensification in recent decades has been a major cause of decline in plant diversity in these habitats. However, the concomitant effects on plant functional diversity are [...] Read more.

Arable field margins are valuable habitats providing a wide range of ecosystem services in rural landscapes. Agricultural intensification in recent decades has been a major cause of decline in plant diversity in these habitats. However, the concomitant effects on plant functional diversity are less documented, particularly in Mediterranean areas. In this paper, we analyzed the effect of margin width and surrounding landscape (cover and diversity of land use and field size), used as proxies for management intensity at local and landscape scales, on plant species richness, functional diversity and functional trait values in margins of winter cereal fields in southern Spain. Five functional traits were selected: life form, growth form, seed mass, seed dispersal mode and pollination type. RLQ and fourth-corner analyses were used to link functional traits and landscape variables. A total of 306 plant species were recorded. Species richness and functional diversity were positively related to margin width but showed no response to landscape variables. Functional trait values were affected neither by the local nor landscape variables. Our results suggest that increasing the margin width of conventionally managed cereal fields would enhance both taxonomic and functional diversity of margin plant assemblages, and thus the services they provide to the agro-ecosystem. Full article

(This article belongs to the Special Issue 2019 Feature Papers by Plants’ Editorial Board Members)

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15 pages, 1041 KiB

Open AccessEditor’s ChoiceArticle

Application of Trichoderma harzianum, 6-Pentyl-α-pyrone and Plant Biopolymer Formulations Modulate Plant Metabolism and Fruit Quality of Plum Tomatoes

by Petronia Carillo, Sheridan L. Woo, Ernesto Comite, Christophe El-Nakhel, Youssef Rouphael, Giovanna Marta Fusco, Assunta Borzacchiello, Stefania Lanzuise and Francesco Vinale

Plants 2020, 9(6), 771; https://doi.org/10.3390/plants9060771 - 19 Jun 2020

Cited by 62 | Viewed by 6515

Abstract

Many Trichoderma are successfully used to improve agriculture productivity due to their capacity for biocontrol and to stimulate plant growth and tolerance to abiotic stress. This research elucidates the effect of applications with Trichoderma harzianum strain T22 (T22), or biopolymer (BP) alone or [...] Read more.

Many Trichoderma are successfully used to improve agriculture productivity due to their capacity for biocontrol and to stimulate plant growth and tolerance to abiotic stress. This research elucidates the effect of applications with Trichoderma harzianum strain T22 (T22), or biopolymer (BP) alone or in combination (BP + T22 or BP + 6-pentyl-α-pyrone (6PP); a Trichoderma secondary metabolite) on the crop performance, nutritional and functional quality of greenhouse tomato (Solanum lycopersicum L. cultivar Pixel). T22 elicited significant increases in total yield (+40.1%) compared to untreated tomato. The content of lycopene, an important antioxidant compound in tomatoes, significantly increased upon treatment with T22 (+ 49%), BP + T22 (+ 40%) and BP + 6PP (+ 52%) compared to the control. T22 treatments significantly increased the content of asparagine (+37%), GABA (+87%) and MEA (+102%) over the control; whereas BP alone strongly increased GABA (+105%) and MEA (+85%). The synthesis of these compounds implies that tomato plants are able to reuse the photorespiratory amino acids and ammonium for producing useful metabolites and reduce the pressure of photorespiration on plant metabolism, thus optimizing photosynthesis and growth. Finally, these metabolites exert many beneficial effects for human health, thus enhancing the premium quality of plum tomatoes. Full article

(This article belongs to the Special Issue 2019 Feature Papers by Plants’ Editorial Board Members)

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20 pages, 3609 KiB

Open AccessArticle

Transcriptome and Network Analyses of Heterostyly in Turnera subulata Provide Mechanistic Insights: Are S-Loci a Red-Light for Pistil Elongation?

by Paige M. Henning, Joel S. Shore and Andrew G. McCubbin

Plants 2020, 9(6), 713; https://doi.org/10.3390/plants9060713 - 3 Jun 2020

Cited by 10 | Viewed by 4451

Abstract

Heterostyly employs distinct hermaphroditic floral morphs to enforce outbreeding. Morphs differ structurally in stigma/anther positioning, promoting cross-pollination, and physiologically blocking self-fertilization. Heterostyly is controlled by a self-incompatibility (S)-locus of a small number of linked S-genes specific to short-styled morph genomes. Turnera [...] Read more.

Heterostyly employs distinct hermaphroditic floral morphs to enforce outbreeding. Morphs differ structurally in stigma/anther positioning, promoting cross-pollination, and physiologically blocking self-fertilization. Heterostyly is controlled by a self-incompatibility (S)-locus of a small number of linked S-genes specific to short-styled morph genomes. Turnera possesses three S-genes, namely TsBAHD (controlling pistil characters), TsYUC6, and TsSPH1 (controlling stamen characters). Here, we compare pistil and stamen transcriptomes of floral morphs of T. subulata to investigate hypothesized S-gene function(s) and whether hormonal differences might contribute to physiological incompatibility. We then use network analyses to identify genetic networks underpinning heterostyly. We found a depletion of brassinosteroid-regulated genes in short styled (S)-morph pistils, consistent with hypothesized brassinosteroid-inactivating activity of TsBAHD. In S-morph anthers, auxin-regulated genes were enriched, consistent with hypothesized auxin biosynthesis activity of TsYUC6. Evidence was found for auxin elevation and brassinosteroid reduction in both pistils and stamens of S- relative to long styled (L)-morph flowers, consistent with reciprocal hormonal differences contributing to physiological incompatibility. Additional hormone pathways were also affected, however, suggesting S-gene activities intersect with a signaling hub. Interestingly, distinct S-genes controlling pistil length, from three species with independently evolved heterostyly, potentially intersect with phytochrome interacting factor (PIF) network hubs which mediate red/far-red light signaling. We propose that modification of the activities of PIF hubs by the S-locus could be a common theme in the evolution of heterostyly. Full article

(This article belongs to the Special Issue 2019 Feature Papers by Plants’ Editorial Board Members)

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18 pages, 5464 KiB

Open AccessArticle

Cloning and Expression of a Perilla frutescens Cytochrome P450 Enzyme Catalyzing the Hydroxylation of Phenylpropenes

by Mariko Baba, Ken-ichi Yamada and Michiho Ito

Plants 2020, 9(5), 577; https://doi.org/10.3390/plants9050577 - 1 May 2020

Cited by 5 | Viewed by 3778

Abstract

Phenylpropanoid volatile components in plants are useful and valuable not only as flavorings, but also as medicines and food supplements. The pharmacological actions and toxicities of these compounds have been well studied but their synthetic pathways are generally unclear. In this study, we [...] Read more.

Phenylpropanoid volatile components in plants are useful and valuable not only as flavorings, but also as medicines and food supplements. The pharmacological actions and toxicities of these compounds have been well studied but their synthetic pathways are generally unclear. In this study, we mined expressed sequence tag libraries of pure strains of perilla maintained for over 30 years for their oil type and conducted gas chromatography-mass spectrometry analyses of the perilla oils to confirm the presence of monohydrates speculated to be intermediates of the phenylpropene synthetics pathways. These putative monohydrate intermediates and their regioisomers were synthesized to identify the reaction products of assays of heterologously expressed enzymes. An enzyme involved in the synthesis of a phenylpropanoid volatile component was identified in perilla. Expression of this enzyme in Saccharomyces cerevisiae showed that it is a member of the cytochrome P450 family and catalyzes the introduction of a hydroxy group onto myristicin to form an intermediate of dillapiole. The enzyme had high sequence similarity to a CYP71D family enzyme, high regiospecificity, and low substrate specificity. This study may aid the elucidation of generally unexploited biosynthetic pathways of phenylpropanoid volatile components. Full article

(This article belongs to the Special Issue 2019 Feature Papers by Plants’ Editorial Board Members)

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20 pages, 1788 KiB

Open AccessEditor’s ChoiceArticle

Mosquito Larvicidal Activity, Antimicrobial Activity, and Chemical Compositions of Essential Oils from Four Species of Myrtaceae from Central Vietnam

by Nguyen Thi Giang An, Le Thi Huong, Prabodh Satyal, Thieu Anh Tai, Do Ngoc Dai, Nguyen Huy Hung, Nguyen Thi Bich Ngoc and William N. Setzer

Plants 2020, 9(4), 544; https://doi.org/10.3390/plants9040544 - 22 Apr 2020

Cited by 49 | Viewed by 7647

Abstract

Mosquitoes are important vectors of several diseases, and control of these insects is imperative for human health. Insecticides have proven useful in controlling mosquito populations, but insecticide resistance and environmental concerns are increasing. Additionally, emerging and re-emerging microbial infections are problematic. Essential oils [...] Read more.

Mosquitoes are important vectors of several diseases, and control of these insects is imperative for human health. Insecticides have proven useful in controlling mosquito populations, but insecticide resistance and environmental concerns are increasing. Additionally, emerging and re-emerging microbial infections are problematic. Essential oils have been shown to be promising mosquito larvicidal agents as well as antimicrobial agents. In this work, the essential oils from four species of Myrtaceae (Baeckea frutescens, Callistemon citrinus, Melaleuca leucadendra, and Syzygium nervosum) growing wild in central Vietnam have been obtained by hydrodistillation and analyzed by gas chromatographic techniques. The essential oils have been screened for mosquito larvicidal activity against Aedes aegypti, Aedes albopictus, and Culex quinquefasciatus, and for antimicrobial activity against Enterococcus faecalis, Staphylococcus aureus, and Candida albicans. Callistemon citrinus fruit essential oil, rich in α-pinene (35.1%), 1,8-cineole (32.4%), limonene (8.2%), and α-terpineol (5.8%) showed good larvicidal activity with 24-h LC₅₀ = 17.3 μg/mL against both Ae. aegypti and Cx. quinquefasciatus, and good antibacterial activity against E. faecalis (minimum inhibitory concentration (MIC) = 16 μg/mL) The 48-h larvicidal activities of M. leucadendra leaf essential oil, rich in α-eudesmol (17.6%), guaiol (10.9%), linalool (5.1%), (E)-caryophyllene (7.0%), and bulnesol (3.6%) were particularly notable, with LC₅₀ of 1.4 and 1.8 μg/mL on Ae. aegypti and Cx. quinquefasciatus. Similarly, M. leucadendra bark essential oil, with α-eudesmol (24.1%) and guaiol (11.3%), showed good antibacterial activity against. E. faecalis. Both B. frutescens and C. citrinus leaf essential oils demonstrated anti-Candida activities with MIC values of 16 μg/mL. The results of this investigation suggest that essential oils derived from the Myrtaceae may serve as “green” alternatives for the control of mosquitoes and/or complementary antimicrobial agents. Full article

(This article belongs to the Special Issue 2019 Feature Papers by Plants’ Editorial Board Members)

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10 pages, 970 KiB

Open AccessArticle

Modeling the Population Dynamics and Management of Italian Ryegrass under Two Climatic Scenarios in Brazil

by Fortunato D. B. Pagnoncelli, Jr., Michelangelo M. Trezzi and Jose L. Gonzalez-Andujar

Plants 2020, 9(3), 325; https://doi.org/10.3390/plants9030325 - 4 Mar 2020

Cited by 4 | Viewed by 3046

Abstract

Italian ryegrass (Lolium multiflorum L.) is an annual grass widely distributed in cultivated crops around the world. This weed causes significant yield reduction in many crops and has developed herbicide resistance. The aim of this study was to develop a cohort-based [...] Read more.

Italian ryegrass (Lolium multiflorum L.) is an annual grass widely distributed in cultivated crops around the world. This weed causes significant yield reduction in many crops and has developed herbicide resistance. The aim of this study was to develop a cohort-based stochastic population dynamics model that integrates both emergence (thermal time) and dynamic population models as a tool to simulate the population dynamics of susceptible and resistant populations of L. multiflorum under the effects of climate change. The current climate scenario and the increase in the average air temperature by 2.5 °C were considered. Chemical and cultural management strategies commonly used in the South Region of Brazil during the winter and summer seasons were incorporated into the model. In the absence of control and under the current climate conditions, the seed bank population grew until reaching an equilibrium density of 19,121 ± 371 seeds m⁻² for the susceptible and 20463 ± 363 seeds m⁻² for the resistant populations. Considering the second climate scenario, the seed bank reaches an equilibrium density of 24,182 ± 253 seeds m⁻² (+26% in relation to the current scenario) for the susceptible population and 24,299 ± 254 seeds m⁻² (+18% in relation to the current scenario) for the resistant one. The results showed that the effect of the rise in temperature implies an increase in population in all the management strategies in relation to the current climate scenario. In both climate scenarios, the strategies based on herbicides application controlling cohorts 1 and 2 were the most efficient, and cropping systems including winter oat-soybeans rotation had a smaller impact on the L. multiflorum seed bank than crop rotations including winter wheat or summer corn. Crop rotations including wheat and corn for L. multiflorum management as an adaptive strategy under the future climate change are suggested. Full article

(This article belongs to the Special Issue 2019 Feature Papers by Plants’ Editorial Board Members)

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15 pages, 2540 KiB

Open AccessArticle

Leaf-Wounding Long-Distance Signaling Targets AtCuAOβ Leading to Root Phenotypic Plasticity

by Ilaria Fraudentali, Renato A. Rodrigues-Pousada, Paraskevi Tavladoraki, Riccardo Angelini and Alessandra Cona

Plants 2020, 9(2), 249; https://doi.org/10.3390/plants9020249 - 15 Feb 2020

Cited by 13 | Viewed by 3229

Abstract

The Arabidopsis gene AtCuAOβ (At4g14940) encodes an apoplastic copper amine oxidase (CuAO) highly expressed in guard cells of leaves and flowers and in root vascular tissues, especially in protoxylem and metaxylem precursors, where its expression is strongly induced by the wound signal methyl [...] Read more.

The Arabidopsis gene AtCuAOβ (At4g14940) encodes an apoplastic copper amine oxidase (CuAO) highly expressed in guard cells of leaves and flowers and in root vascular tissues, especially in protoxylem and metaxylem precursors, where its expression is strongly induced by the wound signal methyl jasmonate (MeJA). The hydrogen peroxide (H₂O₂) derived by the AtCuAOβ-driven oxidation of the substrate putrescine (Put), mediates the MeJA–induced early root protoxylem differentiation. Considering that early root protoxylem maturation was also induced by both exogenous Put and leaf wounding through a signaling pathway involving H₂O₂, in the present study we investigated the role of AtCuAOβ in the leaf wounding-induced early protoxylem differentiation in combination with Put treatment. Quantitative and tissue specific analysis of AtCuAOβ gene expression by RT-qPCR and promoter::green fluorescent protein-β-glucuronidase fusion analysis revealed that wounding of the cotiledonary leaf induced AtCuAOβ gene expression which was particularly evident in root vascular tissues. AtCuAOβ loss-of-function mutants were unresponsive to the injury, not showing altered phenotype upon wounding in comparison to wild type seedlings. Exogenous Put and wounding did not show synergy in inducing early root protoxylem maturation, suggesting their involvement in a shared signaling pathway. Full article

(This article belongs to the Special Issue 2019 Feature Papers by Plants’ Editorial Board Members)

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19 pages, 1611 KiB

Open AccessArticle

β-Aminobutyric Acid Pretreatment Confers Salt Stress Tolerance in Brassica napus L. by Modulating Reactive Oxygen Species Metabolism and Methylglyoxal Detoxification

by Jubayer Al Mahmud, Mirza Hasanuzzaman, M. Iqbal R. Khan, Kamrun Nahar and Masayuki Fujita

Plants 2020, 9(2), 241; https://doi.org/10.3390/plants9020241 - 13 Feb 2020

Cited by 25 | Viewed by 4101

Abstract

Salinity is a serious environmental hazard which limits world agricultural production by adversely affecting plant physiology and biochemistry. Hence, increased tolerance against salt stress is very important. In this study, we explored the function of β-aminobutyric acid (BABA) in enhancing salt stress tolerance [...] Read more.

Salinity is a serious environmental hazard which limits world agricultural production by adversely affecting plant physiology and biochemistry. Hence, increased tolerance against salt stress is very important. In this study, we explored the function of β-aminobutyric acid (BABA) in enhancing salt stress tolerance in rapeseed (Brassica napus L.). After pretreatment with BABA, seedlings were exposed to NaCl (100 and 150 mM) for 2 days. Salt stress increased Na content and decreased K content in shoot and root. It disrupted the antioxidant defense system by producing reactive oxygen species (ROS; H₂O₂ and O₂^•−), methylglyoxal (MG) content and causing oxidative stress. It also reduced the growth and photosynthetic pigments of seedlings but increased proline (Pro) content. However, BABA pretreatment in salt-stressed seedlings increased ascorbate (AsA) and glutathione (GSH) contents; GSH/GSSG ratio; and the activities of ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), glutathione reductase (GR), glutathione peroxidase (GPX), superoxide dismutase (SOD), catalase (CAT), glyoxalase I (Gly I), and glyoxalase II (Gly II) as well as the growth and photosynthetic pigments of plants. In addition, compared to salt stress alone, BABA increased Pro content, reduced the H₂O₂, MDA and MG contents, and decreased Na content in root and increased K content in shoot and root of rapeseed seedlings. Our findings suggest that BABA plays a double role in rapeseed seedlings by reducing Na uptake and enhancing stress tolerance through upregulating the antioxidant defense and glyoxalase systems. Full article

(This article belongs to the Special Issue 2019 Feature Papers by Plants’ Editorial Board Members)

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11 pages, 1450 KiB

Open AccessCommunication

A Leaf Selfie: Using a Smartphone to Quantify Leaf Vulnerability to Hydraulic Dysfunction

by Francesco Petruzzellis, Martina Tomasella, Andrea Miotto, Sara Natale, Patrizia Trifilò and Andrea Nardini

Plants 2020, 9(2), 234; https://doi.org/10.3390/plants9020234 - 11 Feb 2020

Cited by 8 | Viewed by 3947

Abstract

Accurate predictions of species distribution under current and future climate conditions require modeling efforts based on clear mechanistic relationships between climate variables and plant physiological functions. Vulnerability of leaves to xylem embolism is a key mechanistic trait that might be included in these [...] Read more.

Accurate predictions of species distribution under current and future climate conditions require modeling efforts based on clear mechanistic relationships between climate variables and plant physiological functions. Vulnerability of leaves to xylem embolism is a key mechanistic trait that might be included in these modeling efforts. Here, we propose a simple set-up to measure leaf vulnerability to embolism on the basis of the optical method using a smartphone, a light source, and a notebook. Our data show that this proposed set-up can adequately quantify the vulnerability to xylem embolism of leaf major veins in Populus nigra and Ostrya carpinifolia, producing values consistent with those obtained in temperate tree species with other methods, allowing virtually any laboratory to quantify species-specific drought tolerance on the basis of a sound mechanistic trait. Full article

(This article belongs to the Special Issue 2019 Feature Papers by Plants’ Editorial Board Members)

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11 pages, 2507 KiB

Open AccessArticle

ACTIN7 Is Required for Perinuclear Clustering of Chloroplasts during Arabidopsis Protoplast Culture

by Michael B. Sheahan, David A. Collings, Ray J. Rose and David W. McCurdy

Plants 2020, 9(2), 225; https://doi.org/10.3390/plants9020225 - 10 Feb 2020

Cited by 9 | Viewed by 3494

Abstract

In Arabidopsis, the actin gene family comprises eight expressed and two non-expressed ACTIN (ACT) genes. Of the eight expressed isoforms, ACT2, ACT7, and ACT8 are differentially expressed in vegetative tissues and may perform specific roles in development. Using tobacco mesophyll [...] Read more.

In Arabidopsis, the actin gene family comprises eight expressed and two non-expressed ACTIN (ACT) genes. Of the eight expressed isoforms, ACT2, ACT7, and ACT8 are differentially expressed in vegetative tissues and may perform specific roles in development. Using tobacco mesophyll protoplasts, we previously demonstrated that actin-dependent clustering of chloroplasts around the nucleus prior to cell division ensures unbiased chloroplast inheritance. Here, we report that actin-dependent chloroplast clustering in Arabidopsis mesophyll protoplasts is defective in act7 mutants, but not act2-1 or act8-2. ACT7 expression was upregulated during protoplast culture whereas ACT2 and ACT8 expression did not substantially change. In act2-1, ACT7 expression increased in response to loss of ACT2, whereas in act7-1, neither ACT2 nor ACT8 expression changed appreciably in response to the absence of ACT7. Semi-quantitative immunoblotting revealed increased actin concentrations during culture, although total actin in act7-1 was only two-thirds that of wild-type or act2-1 after 96 h culture. Over-expression of ACT2 and ACT8 under control of ACT7 regulatory sequences restored normal levels of chloroplast clustering. These results are consistent with a requirement for ACT7 in actin-dependent chloroplast clustering due to reduced levels of actin protein and gene induction in act7 mutants, rather than strong functional specialization of the ACT7 isoform. Full article

(This article belongs to the Special Issue 2019 Feature Papers by Plants’ Editorial Board Members)

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14 pages, 2764 KiB

Open AccessFeature PaperArticle

Variability in the Capacity to Produce Damage-Induced Aldehyde Green Leaf Volatiles among Different Plant Species Provides Novel Insights into Biosynthetic Diversity

by Jurgen Engelberth and Marie Engelberth

Plants 2020, 9(2), 213; https://doi.org/10.3390/plants9020213 - 6 Feb 2020

Cited by 24 | Viewed by 4017

Abstract

Green leaf volatiles (GLVs) are commonly released by plants upon damage, thereby providing volatile signals for other plants to prepare against the major causes of damage, herbivory, pathogen infection, and cold stress. However, while the biosynthesis of these compounds is generally well understood, [...] Read more.

Green leaf volatiles (GLVs) are commonly released by plants upon damage, thereby providing volatile signals for other plants to prepare against the major causes of damage, herbivory, pathogen infection, and cold stress. However, while the biosynthesis of these compounds is generally well understood, little is known about the qualities and quantities that are released by different plant species, nor is it known if release patterns can be associated with different clades of plants. Here, we provide a first study describing the damage-induced release of major GLVs by more than 50 plant species. We found major differences in the quantity and quality of those compounds between different plant species ranging from undetectable levels to almost 100 µg per gram fresh weight. We also found major shifts in the composition that correlate directly to the quantity of emitted GLV. However, we did not find any major patterns that would associate specific GLV release with distinct clades of plants. Full article

(This article belongs to the Special Issue 2019 Feature Papers by Plants’ Editorial Board Members)

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12 pages, 2404 KiB

Open AccessArticle

Agrobacterium-Mediated Genetic Transformation of the Medicinal Plant Veratrum dahuricum

by Rui Ma, Zhijing Yu, Qinan Cai, Haiyun Li, Yingshan Dong, Kirsi-Marja Oksman-Caldentey and Heiko Rischer

Plants 2020, 9(2), 191; https://doi.org/10.3390/plants9020191 - 4 Feb 2020

Cited by 26 | Viewed by 7347

Abstract

Veratrum dahuricum L. (Liliaceae), a monocotyledonous species distributed throughout the Changbai mountains of Northeast China, is pharmaceutically important, due to the capacity to produce the anticancer drug cyclopamine. An efficient transformation system of Veratrum dahuricum mediated with Agrobacterium tumefaciens is presented. Murashige and [...] Read more.

Veratrum dahuricum L. (Liliaceae), a monocotyledonous species distributed throughout the Changbai mountains of Northeast China, is pharmaceutically important, due to the capacity to produce the anticancer drug cyclopamine. An efficient transformation system of Veratrum dahuricum mediated with Agrobacterium tumefaciens is presented. Murashige and Skoog (MS) medium containing 8 mg/L picloram was used to induce embryogenic calli from immature embryos with 56% efficiency. A. tumefaciens LBA4404 carrying the bar gene driven by the cauliflower mosaic virus 35S promoter was employed for embryogenic callus inoculation. A. tumefaciens cell density OD660 = 0.8 for inoculation, half an hour infection period, and three days of co-culture duration were found to be optimal for callus transformation. Phosphinothricin (PPT, 16 mg/L) was used as the selectable agent, and a transformation efficiency of 15% (transgenic plants/100 infected calli) was obtained. The transgenic nature of the regenerated plants was confirmed by PCR and Southern blot analysis, and expression of the bar gene was detected by RT-PCR and Quick PAT/bar strips. The steroid alkaloids cyclopamine, jervine, and veratramine were detected in transgenic plants, in non-transformed and control plants collected from natural sites. The transformation system constitutes a prerequisite for the production of the pharmaceutically important anticancer drug cyclopamine by metabolic engineering of Veratrum. Full article

(This article belongs to the Special Issue 2019 Feature Papers by Plants’ Editorial Board Members)

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11 pages, 265 KiB

Open AccessArticle

Living Mulch and Organic Fertilization to Improve Weed Management, Yield and Quality of Broccoli Raab in Organic Farming

by Mariano Fracchiolla, Massimiliano Renna, Massimiliano D’Imperio, Cesare Lasorella, Pietro Santamaria and Eugenio Cazzato

Plants 2020, 9(2), 177; https://doi.org/10.3390/plants9020177 - 1 Feb 2020

Cited by 29 | Viewed by 5444

Abstract

Living mulch gives many benefits to agro-ecosystems such as erosion control, nitrogen fixation and nutrient recycling, increasing of organic matter, weed and pest control, and increasing of soil organism. The experiment, carried out in Puglia, Southern Italy on transplanted broccoli raab (cv. Grossa [...] Read more.

Living mulch gives many benefits to agro-ecosystems such as erosion control, nitrogen fixation and nutrient recycling, increasing of organic matter, weed and pest control, and increasing of soil organism. The experiment, carried out in Puglia, Southern Italy on transplanted broccoli raab (cv. Grossa fasanese), evaluated four soil management systems (SMSs): Trifolium subterraneum and T. repens used as living mulch, undisturbed weedy, and conventional tillage. For each SMS, four rates of nitrogen and phosphorous (NP0, NP1, NP2, and NP3) were supplied, using an organic fertilizer. The following data were collected: weed infestation, leaf chlorophyll in the plants (as SPAD units), weight, diameter, and colour of the inflorescences, anion and Mg, Fe, Na, K, Ca content. Fertilization showed prominent effects on most of parameters evaluated. The Sufficient Index of broccoli raab plants was higher in fertilized plots. With the increasing of fertilization rates, weight of primary inflorescences and the marketable yield linearly increased, confirming the great influence of nitrogen fertilization on the yield of Brassicaceae vegetables and highlighting the importance of combining living mulch and fertilization. By increasing fertilization rates, some elements, such as Mg and Fe, increased, whereas a decrease of Na, K, and Ca was observed. The nitrate content in the inflorescences was different only between the fertilized and unfertilized plots, although it was very low. In NP2 and NP3 a greener colour was found. Living mulch did not clearly affect quality and yield of broccoli raab but was effective in weed control. Results show the positive effects of living mulch and organic fertilization in the sustainable production of broccoli raab. Full article

(This article belongs to the Special Issue 2019 Feature Papers by Plants’ Editorial Board Members)

19 pages, 5257 KiB

Open AccessArticle

Using Rapid Chlorophyll Fluorescence Transients to Classify Vitis Genotypes

by Jorge Marques da Silva, Andreia Figueiredo, Jorge Cunha, José Eduardo Eiras-Dias, Sara Silva, Leonardo Vanneschi and Pedro Mariano

Plants 2020, 9(2), 174; https://doi.org/10.3390/plants9020174 - 1 Feb 2020

Cited by 9 | Viewed by 3807

Abstract

When a dark-adapted leaf is illuminated with saturating light, a fast polyphasic rise of fluorescence emission (Kautsky effect) is observed. The shape of the curve is dependent on the molecular organization of the photochemical apparatus, which in turn is a function of the [...] Read more.

When a dark-adapted leaf is illuminated with saturating light, a fast polyphasic rise of fluorescence emission (Kautsky effect) is observed. The shape of the curve is dependent on the molecular organization of the photochemical apparatus, which in turn is a function of the interaction between genotype and environment. In this paper, we evaluate the potential of rapid fluorescence transients, aided by machine learning techniques, to classify plant genotypes. We present results of the application of several machine learning algorithms (k-nearest neighbors, decision trees, artificial neural networks, genetic programming) to rapid induction curves recorded in different species and cultivars of vine grown in the same environmental conditions. The phylogenetic relations between the selected Vitis species and Vitis vinifera cultivars were established with molecular markers. Both neural networks (71.8%) and genetic programming (75.3%) presented much higher global classification success rates than k-nearest neighbors (58.5%) or decision trees (51.6%), genetic programming performing slightly better than neural networks. However, compared with a random classifier (success rate = 14%), even the less successful algorithms were good at the task of classifying. The use of rapid fluorescence transients, handled by genetic programming, for rapid preliminary classification of Vitis genotypes is foreseen as feasible. Full article

(This article belongs to the Special Issue 2019 Feature Papers by Plants’ Editorial Board Members)

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14 pages, 1990 KiB

Open AccessEditor’s ChoiceArticle

Application of Deep Eutectic Solvents for the Extraction of Rutin and Rosmarinic Acid from Satureja montana L. and Evaluation of the Extracts Antiradical Activity

by Martina Jakovljević, Jelena Vladić, Senka Vidović, Kristian Pastor, Stela Jokić, Maja Molnar and Igor Jerković

Plants 2020, 9(2), 153; https://doi.org/10.3390/plants9020153 - 26 Jan 2020

Cited by 28 | Viewed by 5131

Abstract

Satureja montana L. was used in the current research as the plant exhibits numerous health-promoting benefits due to its specific chemical composition. The extraction method based on deep eutectic solvents (DESs) was used for the extraction of rutin and rosmarinic acid from this [...] Read more.

Satureja montana L. was used in the current research as the plant exhibits numerous health-promoting benefits due to its specific chemical composition. The extraction method based on deep eutectic solvents (DESs) was used for the extraction of rutin and rosmarinic acid from this plant. Five different choline chloride-based DESs with different volumes of water (10%, 30%, and 50% (v/v)) were used for the extraction at different temperatures (30, 50, and 70 °C) to investigate the influence on rosmarinic acid and rutin content obtained by high-performance liquid chromatography with diode-array detector (HPLC-DAD) in the obtained extracts. A principal component analysis was employed to explore and visualize the influence of applied parameters on the efficiency of the extraction procedure of rutin and rosmarinic acid. Among the tested DESs, choline chloride:lactic acid (mole ratio 1:2) and choline chloride:levulinic acid (mole ratio 1:2) were the most suitable for the extraction of rutin, while for rosmarinic acid choline chloride:urea (mole ratio 1:2) was the most effective solvent. The extract showing the best antiradical activity was obtained with choline chloride:urea (mole ratio 1:1) at 30 °C and 50% H₂O (v/v). Full article

(This article belongs to the Special Issue 2019 Feature Papers by Plants’ Editorial Board Members)

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14 pages, 959 KiB

Open AccessArticle

Antioxidant and Enzyme Inhibitory Properties of the Polyphenolic-Rich Extract from an Ancient Apple Variety of Central Italy (Mela Rosa dei Monti Sibillini)

by Joice Guileine Nkuimi Wandjou, Serena Mevi, Gianni Sagratini, Sauro Vittori, Stefano Dall’Acqua, Giovanni Caprioli, Giulio Lupidi, Giacomo Mombelli, Sabrina Arpini, Pietro Allegrini, Francisco Les, Víctor López and Filippo Maggi

Plants 2020, 9(1), 9; https://doi.org/10.3390/plants9010009 - 19 Dec 2019

Cited by 14 | Viewed by 3725

Abstract

This study was undertaken to evaluate the nutraceutical potential of the Mela Rosa dei Monti Sibillini (MR), an ancient apple variety of the Sibillini Mountains, central Italy. The chemical profile of the apple’s polyphenolic-rich extract (MRE) obtained from first- and second-choice samples using [...] Read more.

This study was undertaken to evaluate the nutraceutical potential of the Mela Rosa dei Monti Sibillini (MR), an ancient apple variety of the Sibillini Mountains, central Italy. The chemical profile of the apple’s polyphenolic-rich extract (MRE) obtained from first- and second-choice samples using the Amberlite^® XAD7HP resin was analyzed by High Performance Liquid Chromatography with Diode-Array and Mass spectrometry (HPLC-DAD-MS) and 21 phytochemicals were quali–quantitatively determined. For comparative purposes, the polyphenol-rich extract of Annurca (ANE), a southern Italian variety, was analyzed. The antioxidant capacity of MREs was evaluated by Folin–Ciocalteu, 1, 1-diphenyl-2-picrylhydrazyl (DPPH), and 2, 2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) assays. The inhibitory capacity of MREs for the enzymes α-glucosidase, lipase, monoamine oxidase A, tyrosinase, and acetylcholinesterase was also determined. The MREs showed higher polyphenolic and triterpene profiles than the ANE. Their radical scavenging activity was higher than that of ANE and comparable to the reference trolox. The MRE from the second-choice apples displayed higher contents of the 21 phytochemicals investigated. Either MRE from second-choice or first-choice samples showed enzymatic inhibition with IC₅₀ values higher than those of reference inhibitors but worthy of nutraceutical consideration. Taken together, these results show the potential of MRE as a source of bioactive compounds to be used for pharmaceutical, nutraceutical, and cosmeceutical applications has been confirmed. Full article

(This article belongs to the Special Issue 2019 Feature Papers by Plants’ Editorial Board Members)

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20 pages, 5791 KiB

Open AccessArticle

Disentangling the Contributions of Plant Taxonomic and Functional Diversities in Shaping Aboveground Biomass of a Restored Forest Landscape in Southern China

by Md. Abu Hanif, Qingshui Yu, Xingquan Rao and Weijun Shen

Plants 2019, 8(12), 612; https://doi.org/10.3390/plants8120612 - 16 Dec 2019

Cited by 11 | Viewed by 3658

Abstract

Restoration is essential for supporting key ecosystem functions such as aboveground biomass production. However, the relative importance of functional versus taxonomic diversity in predicting aboveground biomass during restoration is poorly studied. Here, we used a trait-based approach to test for the importance of [...] Read more.

Restoration is essential for supporting key ecosystem functions such as aboveground biomass production. However, the relative importance of functional versus taxonomic diversity in predicting aboveground biomass during restoration is poorly studied. Here, we used a trait-based approach to test for the importance of multiple plant diversity attributes in regulating aboveground biomass in a 30-years-old restored subtropical forest in southern China. We show that both taxonomic and functional diversities are significant and positive regulators of aboveground biomass; however, functional diversity (FD) was more important than taxonomic diversity (species richness) in controlling aboveground biomass. FD had the strongest direct effect on aboveground biomass compared with species richness, soil nutrients, and community weighted mean (CWM) traits. Our results further indicate that leaf and root morphological traits and traits related to the nutrient content in plant tissues represent the existence of a leaf and root economic spectrum, and the acquisitive resource use strategy influenced aboveground biomass. Our results suggest that both taxonomic and FD play a role in shaping aboveground biomass, but FD is more important in supporting aboveground biomass in this type of environments. These results imply that enhancing FD is important to restoring and managing degraded forest landscapes. Full article

(This article belongs to the Special Issue 2019 Feature Papers by Plants’ Editorial Board Members)

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18 pages, 1609 KiB

Open AccessArticle

Secoiridoids Metabolism Response to Wounding in Common Centaury (Centaurium erythraea Rafn) Leaves

by Jelena Božunović, Marijana Skorić, Dragana Matekalo, Suzana Živković, Milan Dragićević, Neda Aničić, Biljana Filipović, Tijana Banjanac, Branislav Šiler and Danijela Mišić

Plants 2019, 8(12), 589; https://doi.org/10.3390/plants8120589 - 11 Dec 2019

Cited by 8 | Viewed by 4037

Abstract

Centaurium erythraea Rafn produces and accumulates various biologically active specialized metabolites, including secoiridoid glucosides (SGs), which help plants to cope with unfavorable environmental conditions. Specialized metabolism is commonly modulated in a way to increase the level of protective metabolites, such as SGs. Here, [...] Read more.

Centaurium erythraea Rafn produces and accumulates various biologically active specialized metabolites, including secoiridoid glucosides (SGs), which help plants to cope with unfavorable environmental conditions. Specialized metabolism is commonly modulated in a way to increase the level of protective metabolites, such as SGs. Here, we report the molecular background of the wounding-induced changes in SGs metabolism for the first time. The mechanical wounding of leaves leads to a coordinated up-regulation of SGs biosynthetic genes and corresponding JA-related transcription factors (TFs) after 24 h, which results in the increase of metabolic flux through the biosynthetic pathway and, finally, leads to the elevated accumulation of SGs 96 h upon injury. The most pronounced increase in relative expression was detected for secologanin synthase (CeSLS), highlighting this enzyme as an important point for the regulation of biosynthetic flux through the SG pathway. A similar expression pattern was observed for CeBIS1, imposing itself as the TF that is prominently involved in wound-induced regulation of SGs biosynthesis genes. The high degree of positive correlations between and among the biosynthetic genes and targeted TFs expressions indicate the transcriptional regulation of SGs biosynthesis in response to wounding with a significant role of CeBIS1, which is a known component of the jasmonic acid (JA) signaling pathway. Full article

(This article belongs to the Special Issue 2019 Feature Papers by Plants’ Editorial Board Members)

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19 pages, 885 KiB

Open AccessArticle

Trehalose Protects Maize Plants from Salt Stress and Phosphorus Deficiency

by Md. Motiar Rohman, Md. Robyul Islam, Mahmuda Binte Monsur, Mohammad Amiruzzaman, Masayuki Fujita and Mirza Hasanuzzaman

Plants 2019, 8(12), 568; https://doi.org/10.3390/plants8120568 - 4 Dec 2019

Cited by 64 | Viewed by 6006

Abstract

This study is undertaken to elucidate the role of trehalose (Tre) in mitigating oxidative stress under salinity and low P in maize. Eight-day-old maize seedlings of two maize varieties, BARI Hybrid Maize-7 and BARI Hybrid Maize-9, were subjected to salinity (150 mM NaCl), [...] Read more.

This study is undertaken to elucidate the role of trehalose (Tre) in mitigating oxidative stress under salinity and low P in maize. Eight-day-old maize seedlings of two maize varieties, BARI Hybrid Maize-7 and BARI Hybrid Maize-9, were subjected to salinity (150 mM NaCl), low P (5 µM KH₂PO₄) and their combined stress with or without 10 mM Tre for 15 d. Salinity and combined stress significantly inhibited the shoot length, root length, and root volume, whereas low P increased the root length and volume in both genotypes. Exogenous Tre in the stress treatments increased all of the growth parameters as well as decreased the salinity, low P, and combined stress-mediated Na⁺/K⁺, reactive oxygen species (ROS), malondialdehyde (MDA), lipoxygenase (LOX) activity, and methylglyoxal (MG) in both genotypes. Individually, salinity and low P increased superoxide dismutase (SOD) activity in both genotypes, but combined stress decreased the activity. Peroxidase (POD) activity increased in all stress treatments. Interestingly, Tre application enhanced the SOD activity in all the stress treatments but inhibited the POD activity. Both catalase (CAT) and glutathione peroxidase (GPX) activity were increased by saline and low P stress while the activities inhibited in combined stress. Similar results were found for ascorbate peroxidase (APX), glutathione peroxidase (GR), and dehydroascorbate reductase (DHAR) activities in both genotypes. However, monodehydroascorbate reductase (MDHAR) activity was inhibited in all the stresses. Interestingly, Tre enhanced CAT, APX, GPX, GR, MDHAR, and DHAR activities suggesting the amelioration of ROS scavenging in maize under all the stresses. Conversely, increased glyoxalase activities in saline and low P stress in BHM-9 suggested better MG detoxification system because of the down-regulation of glyoxalase-I (Gly-I) activity in BHM-7 in those stresses. Tre also increased the glyoxalase activities in both genotypes under all the stresses. Tre improved the growth in maize seedlings by decreasing Na⁺/K⁺, ROS, MDA, and MG through regulating antioxidant and glyoxalase systems. Full article

(This article belongs to the Special Issue 2019 Feature Papers by Plants’ Editorial Board Members)

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16 pages, 1661 KiB

Open AccessArticle

Effect of Elevated CO₂ Concentration on the Disease Severity of Compatible and Incompatible Interactions of Brassica napus–Leptosphaeria maculans Pathosystem

by Zhongwei Zou, Fei Liu, Changqin Chen and W. G. Dilantha Fernando

Plants 2019, 8(11), 484; https://doi.org/10.3390/plants8110484 - 8 Nov 2019

Cited by 3 | Viewed by 2709

Abstract

Global warming by increased atmospheric CO₂ concentration has been widely accepted. Yet, there has not been any consistent conclusion on the doubled CO₂ concentration that in the future will affect plant disease incidence and severity. Blackleg disease, mainly caused by Leptosphaeria [...] Read more.

Global warming by increased atmospheric CO₂ concentration has been widely accepted. Yet, there has not been any consistent conclusion on the doubled CO₂ concentration that in the future will affect plant disease incidence and severity. Blackleg disease, mainly caused by Leptosphaeria maculans, is a major disease on canola production globally. Brassica napus and L. maculans have a gene-for-gene interaction, which causes an incompatible reaction between canola plants carrying resistance genes and L. maculans isolates carrying corresponding avirulence genes. In this study, B. napus varieties and lines inoculated with different Leptosphaeria isolates were subjected to simulated growth conditions, namely, growth chambers with normal environments and with controlled CO₂ concentrations of 400, 600, and 800 ppm. The results indicated that the elevated CO₂ concentrations have no noticeable effect on the inferred phenotypes of the canola–blackleg interactions. However, the disease severity decreased in most of the B. napus–L. maculans interactions at extremely high CO₂ concentration (800 ppm). The varied pathogenicity changes of the B. napus–L. maculans pathosystem under elevated CO₂ concentrations at 400 or 600 ppm may be due to the genetic background or physiological differences in plants and pathogenicity differences in L. maculans isolates having different Avr gene profiles. The mechanisms by which elevated CO₂ concentrations affect the B. napus–L. maculans pathosystem will help us understand how climate change will impact crops and diseases. Full article

(This article belongs to the Special Issue 2019 Feature Papers by Plants’ Editorial Board Members)

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17 pages, 1918 KiB

Open AccessArticle

Exogenous Tebuconazole and Trifloxystrobin Regulates Reactive Oxygen Species Metabolism Toward Mitigating Salt-Induced Damages in Cucumber Seedling

by Sayed Mohammad Mohsin, Mirza Hasanuzzaman, M. H. M. Borhannuddin Bhuyan, Khursheda Parvin and Masayuki Fujita

Plants 2019, 8(10), 428; https://doi.org/10.3390/plants8100428 - 18 Oct 2019

Cited by 31 | Viewed by 4850

Abstract

The present study investigated the role of tebuconazole (TEB) and trifloxystrobin (TRI) on cucumber plants (Cucumis sativus L. cv. Tokiwa) under salt stress (60 mM NaCl). The cucumber plants were grown semi-hydroponically in a glasshouse. Plants were exposed to two different doses [...] Read more.

The present study investigated the role of tebuconazole (TEB) and trifloxystrobin (TRI) on cucumber plants (Cucumis sativus L. cv. Tokiwa) under salt stress (60 mM NaCl). The cucumber plants were grown semi-hydroponically in a glasshouse. Plants were exposed to two different doses of fungicides (1.375 µM TEB + 0.5 µM TRI and 2.75 µM TEB + 1.0 µM TRI) solely and in combination with NaCl (60 mM) for six days. The application of salt phenotypically deteriorated the cucumber plant growth that caused yellowing of the whole plant and significantly destructed the contents of chlorophyll and carotenoids. The oxidative damage was created under salinity by increasing the contents of malondialdehyde (MDA), hydrogen peroxide (H₂O₂), and electrolytic leakage (EL) resulting in the disruption of the antioxidant defense system. Furthermore, in the leaves, stems, and roots of cucumber plants increased Na⁺ content was observed under salt stress, whereas the K⁺/Na⁺ ratio and contents of K⁺, Ca²⁺, and Mg²⁺ decreased. In contrast, the exogenous application of TEB and TRI reduced the contents of MDA, H₂O₂, and EL by improving the activities of enzymatic and non-enzymatic antioxidants. In addition, ion homeostasis was regulated by reducing Na⁺ uptake and enhanced K⁺ accumulation and the K⁺/Na⁺ ratio after application of TEB and TRI. Therefore, this study indicates that the exogenous application of TEB and TRI enhanced salt tolerance in cucumber plants by regulating reactive oxygen species production and antioxidant defense systems. Full article

(This article belongs to the Special Issue 2019 Feature Papers by Plants’ Editorial Board Members)

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15 pages, 2639 KiB

Open AccessArticle

Climatic Niche Shift during Azolla filiculoides Invasion and Its Potential Distribution under Future Scenarios

by Argantonio Rodríguez-Merino, Rocío Fernández-Zamudio, Pablo García-Murillo and Jesús Muñoz

Plants 2019, 8(10), 424; https://doi.org/10.3390/plants8100424 - 18 Oct 2019

Cited by 11 | Viewed by 3873

Abstract

In order to prevent future biological invasions, it is crucial to know non-native species distributions. We evaluated the potential global distribution of Azolla filiculoides, a free-floating macrophyte native to the Americas by using species distribution models and niche equivalency tests to analyze [...] Read more.

In order to prevent future biological invasions, it is crucial to know non-native species distributions. We evaluated the potential global distribution of Azolla filiculoides, a free-floating macrophyte native to the Americas by using species distribution models and niche equivalency tests to analyze the degree of niche overlap between the native and invaded ranges of the species. The models were projected under two future emission scenarios, three global circulation models and two time periods. Our results indicate a possible niche shift between the distribution ranges of the species, indicating that A. filiculoides can adapt to novel environmental conditions derived from climatic differences during the invasion process. Our models also show that the future potential distribution of A. filiculoides will decrease globally, although the species could colonize new vulnerable regions where it is currently absent. We highlight that species occurrence records in the invaded area are necessary to generate accurate models, which will, in turn, improve our ability to predict potential invasion risk areas. Full article

(This article belongs to the Special Issue 2019 Feature Papers by Plants’ Editorial Board Members)

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20 pages, 1385 KiB

Open AccessArticle

Morphological and Chemical Profile of Three Tomato (Solanum lycopersicum L.) Landraces of A Semi-Arid Mediterranean Environment

by Massimiliano Renna, Massimiliano D’Imperio, Maria Gonnella, Miriana Durante, Angelo Parente, Giovanni Mita, Pietro Santamaria and Francesco Serio

Plants 2019, 8(8), 273; https://doi.org/10.3390/plants8080273 - 8 Aug 2019

Cited by 14 | Viewed by 4986

Abstract

Puglia (Southern Italy), particularly rich in tomato agro-biodiversity, can be considered a typical region of the semi-arid Mediterranean environments. In this study, three local varieties of tomato (Manduria, Giallo di Crispiano and Regina) were characterized by using morphological descriptors according to international standards. [...] Read more.

Puglia (Southern Italy), particularly rich in tomato agro-biodiversity, can be considered a typical region of the semi-arid Mediterranean environments. In this study, three local varieties of tomato (Manduria, Giallo di Crispiano and Regina) were characterized by using morphological descriptors according to international standards. Chemical (isoprenoids, ascorbic acid, total phenols, sugars and mineral content) and agronomic assessment were carried out to highlight the specific traits of these local varieties well adapted to a semi-arid environment. Data of morphological traits according to the “International Union for the Protection of New Varieties of Plants” (UPOV) guideline evidenced a clear distinctness among all three landraces, especially as regards fruits. Results also highlighted that a great part of variation in chemical traits was almost exclusively due to genotypes, while in a few cases observed differences resulted from the interaction between genotype and harvest time. The results of the present study may represent the first step toward the recognition of “conservation variety” status for Regina, Giallo di Crispiano and Manduria tomato landraces. At the same time, both quality traits and agronomic performance of these tomato genotypes suggest the possibility of their cultivation in other semi-arid environments also considering their quality traits, in view of a sustainable production. Full article

(This article belongs to the Special Issue 2019 Feature Papers by Plants’ Editorial Board Members)

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10 pages, 282 KiB

Open AccessArticle

Temporal, Plant Part, and Interpopulation Variability of Secondary Metabolites and Antioxidant Activity of Inula helenium L.

by Nenad Zlatić, Dragana Jakovljević and Milan Stanković

Plants 2019, 8(6), 179; https://doi.org/10.3390/plants8060179 - 17 Jun 2019

Cited by 30 | Viewed by 4098

Abstract

Variations in abiotic environmental factors have significant effects on quantity and quality of secondary metabolites, which is particularly important for plant species that possess biologically active compounds. The purpose of this study is determination of the total phenolic content, flavonoid concentration, and antioxidant [...] Read more.

Variations in abiotic environmental factors have significant effects on quantity and quality of secondary metabolites, which is particularly important for plant species that possess biologically active compounds. The purpose of this study is determination of the total phenolic content, flavonoid concentration, and antioxidant activity of the different parts of Inula helenium L. (Asteraceae) sampled from different populations and in different time periods. The amounts obtained for the total phenolics varied from 16.73 to 89.85 mg of gallic acid (GA)/g. The concentration of flavonoids ranged from 9.32 to 376.22 mg of rutin (Ru)/g. The IC₅₀ values of antioxidant activity determined using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical method varied from 161.60 to 1563.02 μg/ml. The inflorescence and roots possessed high concentration of phenolic compounds and significant antioxidant activity, while leaves contained the highest concentration of flavonoids. Additionally, the quantity of the phenolics, as well as antioxidant activity, significantly varied among the different populations due to different impacts of environmental factors. This research showed that I. helenium represents an abundant source of bioactive substances, and that the quantity of these compounds greatly differs among the different populations as well as in the same populations regarding the different time periods as well as plant parts. Full article

(This article belongs to the Special Issue 2019 Feature Papers by Plants’ Editorial Board Members)

14 pages, 3228 KiB

Open AccessArticle

Factors Affecting the Regeneration, via Organogenesis, and the Selection of Transgenic Calli in the Peach Rootstock Hansen 536 (Prunus persica × Prunus amygdalus) to Express an RNAi Construct against PPV Virus

by Silvia Sabbadini, Angela Ricci, Cecilia Limera, Dania Baldoni, Luca Capriotti and Bruno Mezzetti

Plants 2019, 8(6), 178; https://doi.org/10.3390/plants8060178 - 17 Jun 2019

Cited by 11 | Viewed by 5518

Abstract

Prunus spp. is one of the most recalcitrant fruit tree species in terms of in vitro regeneration and transformation, mostly when mature tissues are used as explants. The present study describes the in vitro regeneration via indirect organogenesis, and Agrobacterium tumefaciens-mediated transformation [...] Read more.

Prunus spp. is one of the most recalcitrant fruit tree species in terms of in vitro regeneration and transformation, mostly when mature tissues are used as explants. The present study describes the in vitro regeneration via indirect organogenesis, and Agrobacterium tumefaciens-mediated transformation of the peach rootstock Hansen 536 (Prunus persica × Prunus amygdalus) through the use of meristematic bulks (MBs) as starting explants. Efficient adventitious shoot regeneration was obtained when Hansen 536 MBs were cultured on an optimized medium consisting of modified McCown Woody Plant medium (WPM) enriched with 4.4 μM 6-Benzyladenine (BA), 0.1 μM 1-Naphthaleneacetic acid (NAA) and 6.0 g L⁻¹ plant agar S1000 (B&V). MB slices were used later as starting explants for Agrobacterium-mediated transformation to introduce an RNAi construct “ihp35S-PPV194” against PPV virus. Transgenic events were identified by both green fluorescent protein (GFP) screening and kanamycin selection at different concentrations (0, 17 or 42 μM). GFP-fluorescent proliferating callus lines were selected and confirmed to stably express the ihp35S-PPV194::eGFP gene construct by molecular analysis. Although shoot regeneration from these transgenic calli has not been obtained yet, this represents one of the few examples of successful attempts in peach genetic transformation from somatic tissues, and also serves as a useful in vitro system for future gene functional analysis in peach. Full article

(This article belongs to the Special Issue 2019 Feature Papers by Plants’ Editorial Board Members)

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26 pages, 3924 KiB

Open AccessArticle

Transcriptomic Analysis Identifies New Non-Target Site Glyphosate-Resistance Genes in Conyza bonariensis

by Cristiano Piasecki, Yongil Yang, Daiane P. Benemann, Frederico S. Kremer, Vanessa Galli, Reginald J. Millwood, Joanei Cechin, Dirceu Agostinetto, Luciano C. Maia, Leandro Vargas and C. Neal Stewart, Jr.

Plants 2019, 8(6), 157; https://doi.org/10.3390/plants8060157 - 7 Jun 2019

Cited by 28 | Viewed by 5109

Abstract

Conyza bonariensis (hairy fleabane) is one of the most problematic and widespread glyphosate-resistant weeds in the world. This highly competitive weed species significantly interferes with crop growth and substantially decreases crop yield. Despite its agricultural importance, the molecular mechanisms of glyphosate resistance are [...] Read more.

Conyza bonariensis (hairy fleabane) is one of the most problematic and widespread glyphosate-resistant weeds in the world. This highly competitive weed species significantly interferes with crop growth and substantially decreases crop yield. Despite its agricultural importance, the molecular mechanisms of glyphosate resistance are still unknown. The present RNA-Seq study was performed with the goal of identifying differentially expressed candidate transcripts (genes) related to metabolism-based non-target site glyphosate resistance in C. bonariensis. The whole-transcriptome was de novo assembled from glyphosate-resistant and -sensitive biotypes of C. bonariensis from Southern Brazil. The RNA was extracted from untreated and glyphosate-treated plants at several timepoints up to 288 h after treatment in both biotypes. The transcriptome assembly produced 90,124 contigs with an average length of 777 bp and N50 of 1118 bp. In response to glyphosate treatment, differential gene expression analysis was performed on glyphosate-resistant and -sensitive biotypes. A total of 9622 genes were differentially expressed as a response to glyphosate treatment in both biotypes, 4297 (44.6%) being up- and 5325 (55.4%) down-regulated. The resistant biotype presented 1770 up- and 2333 down-regulated genes while the sensitive biotype had 2335 and 2800 up- and down-regulated genes, respectively. Among them, 974 up- and 1290 down-regulated genes were co-expressed in both biotypes. In the present work, we identified 41 new candidate target genes from five families related to herbicide transport and metabolism: 19 ABC transporters, 10 CYP450s, one glutathione S-transferase (GST), five glycosyltransferases (GT), and six genes related to antioxidant enzyme catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD). The candidate genes may participate in metabolic-based glyphosate resistance via oxidation, conjugation, transport, and degradation, plus antioxidation. One or more of these genes might ‘rescue’ resistant plants from irreversible damage after glyphosate treatment. The 41 target genes we report in the present study may inform further functional genomics studies, including gene editing approaches to elucidate glyphosate-resistance mechanisms in C. bonariensis. Full article

(This article belongs to the Special Issue 2019 Feature Papers by Plants’ Editorial Board Members)

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Review

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15 pages, 1308 KiB

Open AccessReview

Current State and Perspectives in Population Genomics of the Common Bean

by Gaia Cortinovis, Giulia Frascarelli, Valerio Di Vittori and Roberto Papa

Plants 2020, 9(3), 330; https://doi.org/10.3390/plants9030330 - 5 Mar 2020

Cited by 17 | Viewed by 4915

Abstract

Population genomics integrates advances in sequencing technologies, bioinformatics tools, statistical methods and software into research on evolutionary and population genetics. Its application has provided novel approaches that have significantly advanced our understanding of new and long-standing questions in evolutionary processes. This has allowed [...] Read more.

Population genomics integrates advances in sequencing technologies, bioinformatics tools, statistical methods and software into research on evolutionary and population genetics. Its application has provided novel approaches that have significantly advanced our understanding of new and long-standing questions in evolutionary processes. This has allowed the disentangling of locus-specific effects from genome-wide effects and has shed light on the genomic basis of fitness, local adaptation and phenotypes. “-Omics” tools have provided a comprehensive genome-wide view of the action of evolution. The specific features of the Phaseolus genus have made it a unique example for the study of crop evolution. The well-documented history of multiple domestications in Phaseolus vulgaris L. (common bean) and its further adaptation to different environments have provided the opportunity to investigate evolutionary issues, such as convergent evolution in the same species across different domestication events. Moreover, the availability of the P. vulgaris reference genome now allows adaptive variations to be easily mapped across the entire genome. Here, we provide an overview of the most significant outcomes obtained in common bean through the use of different computational tools for analysis of population genomics data. Full article

(This article belongs to the Special Issue 2019 Feature Papers by Plants’ Editorial Board Members)

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23 pages, 1691 KiB

Open AccessEditor’s ChoiceReview

Citrus Flavones: An Update on Sources, Biological Functions, and Health Promoting Properties

by Davide Barreca, Giuseppina Mandalari, Antonella Calderaro, Antonella Smeriglio, Domenico Trombetta, Maria Rosa Felice and Giuseppe Gattuso

Plants 2020, 9(3), 288; https://doi.org/10.3390/plants9030288 - 26 Feb 2020

Cited by 96 | Viewed by 7691

Abstract

Citrus spp. are among the most widespread plants cultivated worldwide and every year millions of tons of fruit, juices, or processed compounds are produced and consumed, representing one of the main sources of nutrients in human diet. Among these, the flavonoids play a [...] Read more.

Citrus spp. are among the most widespread plants cultivated worldwide and every year millions of tons of fruit, juices, or processed compounds are produced and consumed, representing one of the main sources of nutrients in human diet. Among these, the flavonoids play a key role in providing a wide range of health beneficial effects. Apigenin, diosmetin, luteolin, acacetin, chrysoeriol, and their respective glycosides, that occur in concentrations up to 60 mg/L, are the most common flavones found in Citrus fruits and juices. The unique characteristics of their basic skeleton and the nature and position of the substituents have attracted and stimulated vigorous investigations as a consequence of an enormous biological potential, that manifests itself as (among other properties) antioxidant, anti-inflammatory, antiviral, antimicrobial, and anticancer activities. This review analyzes the biochemical, pharmacological, and biological properties of Citrus flavones, emphasizing their occurrence in Citrus spp. fruits and juices, on their bioavailability, and their ability to modulate signal cascades and key metabolic enzymes both in vitro and in vivo. Electronic databases including PubMed, Scopus, Web of Science, and SciFinder were used to investigate recent published articles on Citrus spp. in terms of components and bioactivity potentials. Full article

(This article belongs to the Special Issue 2019 Feature Papers by Plants’ Editorial Board Members)

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18 pages, 1262 KiB

Open AccessEditor’s ChoiceReview

Soybean Resistance to Soybean Mosaic Virus

by Kristin Widyasari, Mazen Alazem and Kook-Hyung Kim

Plants 2020, 9(2), 219; https://doi.org/10.3390/plants9020219 - 8 Feb 2020

Cited by 45 | Viewed by 11033

Abstract

Soybean mosaic virus (SMV) occurs in all soybean-growing areas in the world and causes huge losses in soybean yields and seed quality. During early viral infection, molecular interactions between SMV effector proteins and the soybean resistance (R) protein, if present, determine the development [...] Read more.

Soybean mosaic virus (SMV) occurs in all soybean-growing areas in the world and causes huge losses in soybean yields and seed quality. During early viral infection, molecular interactions between SMV effector proteins and the soybean resistance (R) protein, if present, determine the development of resistance/disease in soybean plants. Depending on the interacting strain and cultivar, R-protein in resistant soybean perceives a specific SMV effector, which triggers either the extreme silent resistance or the typical resistance manifested by hypersensitive responses and induction of salicylic acid and reactive oxygen species. In this review, we consider the major advances that have been made in understanding the soybean–SMV arms race. We also focus on dissecting mechanisms SMV employs to establish infection and how soybean perceives and then responds to SMV attack. In addition, progress on soybean R-genes studies, as well as those addressing independent resistance genes, are also addressed. Full article

(This article belongs to the Special Issue 2019 Feature Papers by Plants’ Editorial Board Members)

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12 pages, 285 KiB

Open AccessReview

The Role of Plasmodesmata-Associated Receptor in Plant Development and Environmental Response

by Minh Huy Vu, Arya Bagus Boedi Iswanto, Jinsu Lee and Jae-Yean Kim

Plants 2020, 9(2), 216; https://doi.org/10.3390/plants9020216 - 7 Feb 2020

Cited by 15 | Viewed by 4367

Abstract

Over the last decade, plasmodesmata (PD) symplasmic nano-channels were reported to be involved in various cell biology activities to prop up within plant growth and development as well as environmental stresses. Indeed, this is highly influenced by their native structure, which is lined [...] Read more.

Over the last decade, plasmodesmata (PD) symplasmic nano-channels were reported to be involved in various cell biology activities to prop up within plant growth and development as well as environmental stresses. Indeed, this is highly influenced by their native structure, which is lined with the plasma membrane (PM), conferring a suitable biological landscape for numerous plant receptors that correspond to signaling pathways. However, there are more than six hundred members of Arabidopsis thaliana membrane-localized receptors and over one thousand receptors in rice have been identified, many of which are likely to respond to the external stimuli. This review focuses on the class of plasmodesmal-receptor like proteins (PD-RLPs)/plasmodesmal-receptor-like kinases (PD-RLKs) found in planta. We summarize and discuss the current knowledge regarding RLPs/RLKs that reside at PD–PM channels in response to plant growth, development, and stress adaptation. Full article

(This article belongs to the Special Issue 2019 Feature Papers by Plants’ Editorial Board Members)

15 pages, 457 KiB

Open AccessEditor’s ChoiceReview

Farming without Glyphosate?

by Hugh J. Beckie, Ken C. Flower and Michael B. Ashworth

Plants 2020, 9(1), 96; https://doi.org/10.3390/plants9010096 - 11 Jan 2020

Cited by 88 | Viewed by 14082

Abstract

Recent statements from scientific organisations and court decisions have resulted in widespread public interest and concern over the safety of glyphosate, the most popular and effective herbicide used worldwide. Consequently, glyphosate-based products are under intense scrutiny from governments at all levels. Some jurisdictions [...] Read more.

Recent statements from scientific organisations and court decisions have resulted in widespread public interest and concern over the safety of glyphosate, the most popular and effective herbicide used worldwide. Consequently, glyphosate-based products are under intense scrutiny from governments at all levels. Some jurisdictions have already banned or restricted its use, which will adversely impact international trade in bulk grain commmodities if glyphosate residues are detected. The possibility of farming without glyphosate is becoming an important issue facing the agri-food research and development sector. Contingency plans need to be formulated if that scenario becomes a reality. In this review, we briefly summarize international events that have led to this possible situation, describe current glyphosate usage in major agronomic field crops worldwide, outline possible alternatives to glyphosate in two agroregions and perform bioeconomic model scenarios of southern Australian broadacre cropping systems without the herbicide. Model predictions suggest that we can farm profitably without glyphosate by consistently utilizing key non-herbicidal weed management practices combined with robust pre-emergence soil residual herbicide treatments. However, maintaining low weed seed banks will be challenging. If the social license to use glyphosate is revoked, what other pesticides will soon follow? Full article

(This article belongs to the Special Issue 2019 Feature Papers by Plants’ Editorial Board Members)

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20 pages, 1613 KiB

Open AccessEditor’s ChoiceReview

Integration of Abscisic Acid Signaling with Other Signaling Pathways in Plant Stress Responses and Development

by Manu Kumar, Mahipal Singh Kesawat, Asjad Ali, Sang-Choon Lee, Sarvajeet Singh Gill and Hyun Uk Kim

Plants 2019, 8(12), 592; https://doi.org/10.3390/plants8120592 - 11 Dec 2019

Cited by 94 | Viewed by 11394

Abstract

Plants are immobile and, to overcome harsh environmental conditions such as drought, salt, and cold, they have evolved complex signaling pathways. Abscisic acid (ABA), an isoprenoid phytohormone, is a critical signaling mediator that regulates diverse biological processes in various organisms. Significant progress has [...] Read more.

Plants are immobile and, to overcome harsh environmental conditions such as drought, salt, and cold, they have evolved complex signaling pathways. Abscisic acid (ABA), an isoprenoid phytohormone, is a critical signaling mediator that regulates diverse biological processes in various organisms. Significant progress has been made in the determination and characterization of key ABA-mediated molecular factors involved in different stress responses, including stomatal closure and developmental processes, such as seed germination and bud dormancy. Since ABA signaling is a complex signaling network that integrates with other signaling pathways, the dissection of its intricate regulatory network is necessary to understand the function of essential regulatory genes involved in ABA signaling. In the present review, we focus on two aspects of ABA signaling. First, we examine the perception of the stress signal (abiotic and biotic) and the response network of ABA signaling components that transduce the signal to the downstream pathway to respond to stress tolerance, regulation of stomata, and ABA signaling component ubiquitination. Second, ABA signaling in plant development processes, such as lateral root growth regulation, seed germination, and flowering time regulation is investigated. Examining such diverse signal integration dynamics could enhance our understanding of the underlying genetic, biochemical, and molecular mechanisms of ABA signaling networks in plants. Full article

(This article belongs to the Special Issue 2019 Feature Papers by Plants’ Editorial Board Members)

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18 pages, 665 KiB

Open AccessReview

Valuable Fatty Acids in Bryophytes—Production, Biosynthesis, Analysis and Applications

by Yi Lu, Finnur Freyr Eiriksson, Margrét Thorsteinsdóttir and Henrik Toft Simonsen

Plants 2019, 8(11), 524; https://doi.org/10.3390/plants8110524 - 19 Nov 2019

Cited by 30 | Viewed by 6917

Abstract

Bryophytes (mosses, liverworts and hornworts) often produce high amounts of very long-chain polyunsaturated fatty acids (vl-PUFAs) including arachidonic acid (AA, 20:4 Δ5,8,11,14) and eicosapentaenoic acid (EPA, 20:5 Δ5,8,11,14,17). The presence of vl-PUFAs is common for marine organisms such as algae, but rarely found [...] Read more.

Bryophytes (mosses, liverworts and hornworts) often produce high amounts of very long-chain polyunsaturated fatty acids (vl-PUFAs) including arachidonic acid (AA, 20:4 Δ5,8,11,14) and eicosapentaenoic acid (EPA, 20:5 Δ5,8,11,14,17). The presence of vl-PUFAs is common for marine organisms such as algae, but rarely found in higher plants. This could indicate that bryophytes did not lose their marine origin completely when they landed into the non-aqueous environment. Vl-PUFA, especially the omega-3 fatty acid EPA, is essential in human diet for its benefits on healthy brain development and inflammation modulation. Recent studies are committed to finding new sources of vl-PUFAs instead of fish and algae oil. In this review, we summarize the fatty acid compositions and contents in the previous studies, as well as the approaches for qualification and quantification. We also conclude different approaches to enhance AA and EPA productions including biotic and abiotic stresses. Full article

(This article belongs to the Special Issue 2019 Feature Papers by Plants’ Editorial Board Members)

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10 pages, 5421 KiB

Open AccessTechnical Note

Rpv Mediated Defense Responses in Grapevine Offspring Resistant to Plasmopara viticola

by Tyrone Possamai, Daniele Migliaro, Massimo Gardiman, Riccardo Velasco and Barbara De Nardi

Plants 2020, 9(6), 781; https://doi.org/10.3390/plants9060781 - 22 Jun 2020

Cited by 28 | Viewed by 3851

Abstract

Downy mildew, caused by the biotrophic oomycete Plasmopara viticola, is one of the most serious grapevine diseases. The development of new varieties, showing partial resistance to downy mildew, through traditional breeding provides a sustainable and effective solution for disease management. Marker-assisted-selection (MAS) [...] Read more.

Downy mildew, caused by the biotrophic oomycete Plasmopara viticola, is one of the most serious grapevine diseases. The development of new varieties, showing partial resistance to downy mildew, through traditional breeding provides a sustainable and effective solution for disease management. Marker-assisted-selection (MAS) provide fast and cost-effective genotyping methods, but phenotyping remains necessary to characterize the host–pathogen interaction and assess the effective resistance level of new varieties as well as to validate MAS selection. In this study, the Rpv mediated defense responses were investigated in 31 genotypes, encompassing susceptible and resistant varieties and 26 seedlings, following inoculation of leaf discs with P. viticola. The offspring differed in Rpv loci inherited (none, one or two): Rpv3-3 and Rpv10 from Solaris and Rpv3-1 and Rpv12 from Kozma 20-3. To improve the assessment of different resistance responses, pathogen reaction (sporulation) and host reaction (necrosis) were scored separately as independent features. They were differently expressed depending on Rpv locus: offspring carrying Rpv3-1 and Rpv12 loci showed the strongest resistance response (scarce sporulation and necrosis), those carrying Rpv3-3 locus showed the highest levels of necrosis while Rpv10 carrying genotypes showed intermediate levels of both sporulation and necrosis. Full article

(This article belongs to the Special Issue 2019 Feature Papers by Plants’ Editorial Board Members)

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6 pages, 1225 KiB

Open AccessTechnical Note

Easy-to-Use InDel Markers for Genetic Mapping between Col-0 and Ler-0 Accessions of Arabidopsis thaliana

by Takahiro Tanaka, Yuichi Nishii, Hirotoshi Matsuo and Taku Takahashi

Plants 2020, 9(6), 779; https://doi.org/10.3390/plants9060779 - 22 Jun 2020

Cited by 3 | Viewed by 4350

Abstract

Map-based gene cloning has played a key role in many genetic studies using the model plant, Arabidopsis thaliana. In the post- next generation sequencing era, identification of point mutations and their corresponding genes is increasingly becoming a powerful and important approach to [...] Read more.

Map-based gene cloning has played a key role in many genetic studies using the model plant, Arabidopsis thaliana. In the post- next generation sequencing era, identification of point mutations and their corresponding genes is increasingly becoming a powerful and important approach to define plant gene function. To perform initial mapping experiments efficiently on Arabidopsis mutants, enrichment of easy-to-use and reliable polymorphic DNA markers would be desirable. We present here a list of InDel polymorphic markers between Col-0 and Ler-0 accessions that can be detected in standard agarose gel electrophoresis. Full article

(This article belongs to the Special Issue 2019 Feature Papers by Plants’ Editorial Board Members)

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11 pages, 2172 KiB

Open AccessBrief Report

Genotypic Variation in Resistance Gene-Mediated Calcium Signaling and Hormonal Signaling Involved in Effector-Triggered Immunity or Disease Susceptibility in the Xanthomonas campestris pv. Campestris–Brassica napus Pathosystem

by Md. Al Mamun, Md. Tabibul Islam, Bok-Rye Lee, Van Hien La, Dong-Won Bae and Tae-Hwan Kim

Plants 2020, 9(3), 303; https://doi.org/10.3390/plants9030303 - 1 Mar 2020

Cited by 16 | Viewed by 3919

Abstract

To characterize cultivar variation in resistance gene (R-gene)-mediated calcium signaling and hormonal regulation in effector-triggered immunity (ETI) and disease susceptibility, Xanthomonas campestris pv. campestris (Xcc) was inoculated in two Brassica napus cultivars (cvs. Capitol and Mosa). At 14 days post inoculation [...] Read more.

To characterize cultivar variation in resistance gene (R-gene)-mediated calcium signaling and hormonal regulation in effector-triggered immunity (ETI) and disease susceptibility, Xanthomonas campestris pv. campestris (Xcc) was inoculated in two Brassica napus cultivars (cvs. Capitol and Mosa). At 14 days post inoculation (DPI) with Xcc, there was a necrotic lesion in cv. Mosa along with the significant accumulation of H₂O₂ and malondialdehyde (MDA), whereas no visual symptom was observed in cv. Capitol. The cultivar variations in the R-gene expressions were found in response to Xcc. ZAR1 is a coiled-coil-nucleotide binding site-leucine-rich repeat (CC-NB-LRR)-type R-gene that is significantly induced in cv. Capitol, whereas toll/interleukin-1 receptor-nucleotide binding site-leucine-rich repeat (TIR-NB-LRR)-type R-gene, TAO1, is significantly upregulated in cv. Mosa Xcc-inoculated plants. The defense-related gene’s non-race-specific disease resistance 1 (NDR1) and mitogen-activated protein kinase 6 (MAPK6) were enhanced, whereas calcium-dependent protein kinase (CDPK5) and calcium-sensing protein 60g (CBP60g) were depressed in cv. Capitol Xcc inoculated plants, and opposite results were found in cv. Mosa. The calcium-sensing receptor (CAS), calmodulin (CaM), expression was induced in both the cultivars. However, the CAS induction rate was much higher in cv. Mosa than in cv. Capitol in response to Xcc. The phytohormone salicylic acid (SA) and jasmonic acid (JA) levels were significantly higher in cv. Capitol along with the enhanced SA receptors (NPR3 and NPR4) and JA synthesis and signaling-related gene expression (LOX2, PDF1.2), whereas the JA level was significantly lower in cv. Mosa Xcc inoculated plants. The SA synthesis and signaling-related genes (ICS1, NPR1) and SA were present at higher levels in cv. Mosa; additionally, the SA level present was much higher in the susceptible cultivar (cv. Mosa) than in the resistant cultivar (cv. Capitol) in response to Xcc. These results indicate that ZAR1 mediated the coordinated action of SA and JA synthesis and signaling to confirm ETI, whereas TAO1 enhanced the synthesis of SA through CAS and CBP60g to antagonize JA synthesis and signaling to cause disease susceptibility in the Brassica napus–Xcc pathosystem. Full article

(This article belongs to the Special Issue 2019 Feature Papers by Plants’ Editorial Board Members)

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2019 Feature Papers by Plants’ Editorial Board Members

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