Jasmonic acid and nitric oxide protects naranjilla (Solanum quitoense) against infection by Fusarium oxysporum f. sp. quitoense by eliciting plant defense responses

2019 ◽  
Vol 106 ◽  
pp. 129-136 ◽  
Author(s):  
Ana Cristina Ávila ◽  
José Ochoa ◽  
Karina Proaño ◽  
M. Carmen Martínez
Keyword(s):  
Nitric Oxide ◽  
Jasmonic Acid ◽  
Plant Defense ◽  
Fusarium Oxysporum ◽  
Defense Responses ◽  
Plant Defense Responses

scholarly journals Jasmonic Acid at the Crossroads of Plant Immunity and Pseudomonas syringae Virulence

2020 ◽  
Vol 21 (20) ◽  
pp. 7482
Author(s):  
Aarti Gupta ◽  
Mamta Bhardwaj ◽  
Lam-Son Phan Tran
Keyword(s):  
Jasmonic Acid ◽  
Plant Defense ◽  
Pseudomonas Syringae ◽  
Regulatory Networks ◽  
Genetic Manipulation ◽  
Plant Immunity ◽  
Stomatal Closure ◽  
Defense Responses ◽  
Plant Defense Responses ◽  
Callose Deposition

Sensing of pathogen infection by plants elicits early signals that are transduced to affect defense mechanisms, such as effective blockage of pathogen entry by regulation of stomatal closure, cuticle, or callose deposition, change in water potential, and resource acquisition among many others. Pathogens, on the other hand, interfere with plant physiology and protein functioning to counteract plant defense responses. In plants, hormonal homeostasis and signaling are tightly regulated; thus, the phytohormones are qualified as a major group of signaling molecules controlling the most widely tinkered regulatory networks of defense and counter-defense strategies. Notably, the phytohormone jasmonic acid mediates plant defense responses to a wide array of pathogens. In this review, we present the synopsis on the jasmonic acid metabolism and signaling, and the regulatory roles of this hormone in plant defense against the hemibiotrophic bacterial pathogen Pseudomonas syringae. We also elaborate on how this pathogen releases virulence factors and effectors to gain control over plant jasmonic acid signaling to effectively cause disease. The findings discussed in this review may lead to ideas for the development of crop cultivars with enhanced disease resistance by genetic manipulation.

scholarly journals Validamycin A Induces Broad-Spectrum Resistance Involving Salicylic Acid and Jasmonic Acid/Ethylene Signaling Pathways

2020 ◽  
Vol 33 (12) ◽  
pp. 1424-1437
Author(s):  
Chuanhong Bian ◽  
Yabing Duan ◽  
Jueyu Wang ◽  
Qian Xiu ◽  
Jianxin Wang ◽  
...  
Keyword(s):  
Salicylic Acid ◽  
Jasmonic Acid ◽  
Plant Defense ◽  
Signaling Pathways ◽  
Broad Spectrum ◽  
Defense Responses ◽  
Systemic Resistance ◽  
Signal Pathways ◽  
Plant Defense Responses ◽  
Validamycin A

Validamycin A (VMA) is an aminoglycoside antibiotic used to control rice sheath blight. Although it has been reported that VMA can induce the plant defense responses, the mechanism remains poorly understood. Here, we found that reactive oxygen species (ROS) bursts and callose deposition in Arabidopsis thaliana, rice (Oryza sativa L.), and wheat (Triticum aestivum L.) were induced by VMA and were most intense with 10 μg of VMA per milliliter at 24 h. Moreover, we showed that VMA induced resistance against Pseudomonas syringae, Botrytis cinerea, and Fusarium graminearum in Arabidopsis leaves, indicating that VMA induces broad-spectrum disease resistance in both dicots and monocots. In addition, VMA-mediated resistance against P. syringae was not induced in NahG transgenic plants, was partially decreased in npr1 mutants, and VMA-mediated resistance to B. cinerea was not induced in npr1, jar1, and ein2 mutants. These results strongly indicated that VMA triggers plant defense responses to both biotrophic and necrotrophic pathogens involved in salicylic acid (SA) and jasmonic acid/ethylene (JA/ET) signaling pathways and is dependent on NPR1. In addition, transcriptome analysis further revealed that VMA regulated the expression of genes involved in SA, JA/ET, abscisic acid (ABA), and auxin signal pathways. Taken together, VMA induces systemic resistance involving in SA and JA/ET signaling pathways and also exerts a positive influence on ABA and auxin signaling pathways. Our study highlights the creative application of VMA in triggering plant defense responses against plant pathogens, providing a valuable insight into applying VMA to enhance plant resistance and reduce the use of chemical pesticides. [Formula: see text] Copyright © 2020 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

scholarly journals Lilium regale Wilson WRKY2 Regulates Chitinase Gene Expression During the Response to the Root Rot Pathogen Fusarium oxysporum

2021 ◽  
Vol 12 ◽  
Author(s):  
Shan Li ◽  
Jun Hai ◽  
Zie Wang ◽  
Jie Deng ◽  
Tingting Liang ◽  
...  
Keyword(s):  
Plant Defense ◽  
Fusarium Oxysporum ◽  
Transgenic Tobacco ◽  
Root Rot ◽  
Defense Responses ◽  
Plant Defense Responses ◽  
Mobility Shift ◽  
Lilium Regale ◽  
Mobility Shift Assay ◽  
Antioxidant Stress

Root rot, mainly caused by Fusarium oxysporum, is the most destructive disease affecting lily (Lilium spp.) production. The WRKY transcription factors (TFs) have important roles during plant immune responses. To clarify the effects of WRKY TFs on plant defense responses to pathogens, a WRKY gene (LrWRKY2) was isolated from Lilium regale Wilson, which is a wild lily species highly resistant to F. oxysporum. The expression of LrWRKY2, which encodes a nuclear protein, is induced by various hormones (methyl jasmonate, ethephon, salicylic acid, and hydrogen peroxide) and by F. oxysporum infection. In this study, LrWRKY2-overexpressing transgenic tobacco plants were more resistant to F. oxysporum than the wild-type plants. Moreover, the expression levels of jasmonic acid biosynthetic pathway-related genes (NtAOC, NtAOS, NtKAT, NtPACX, NtJMT, NtOPR, and NtLOX), pathogenesis-related genes (NtCHI, NtGlu2, and NtPR-1), and antioxidant stress-related superoxide dismutase genes (NtSOD, NtCu-ZnSOD, and MnSOD) were significantly up-regulated in LrWRKY2 transgenic tobacco lines. Additionally, the transient expression of a hairpin RNA targeting LrWRKY2 increased the susceptibility of L. regale scales to F. oxysporum. Furthermore, an F. oxysporum resistance gene (LrCHI2) encoding a chitinase was isolated from L. regale. An electrophoretic mobility shift assay demonstrated that LrWRKY2 can bind to the LrCHI2 promoter containing the W-box element. Yeast one-hybrid assay results suggested that LrWRKY2 can activate LrCHI2 transcription. An examination of transgenic tobacco transformed with LrWRKY2 and the LrCHI2 promoter revealed that LrWRKY2 activates the LrCHI2 promoter. Therefore, in L. regale, LrWRKY2 is an important positive regulator that contributes to plant defense responses to F. oxysporum by modulating LrCHI2 expression.

scholarly journals An efficient direct screening system for microorganisms that activate plant immune responses based on plant–microbe interactions using cultured plant cells

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mari Kurokawa ◽  
Masataka Nakano ◽  
Nobutaka Kitahata ◽  
Kazuyuki Kuchitsu ◽  
Toshiki Furuya
Keyword(s):  
Immune Responses ◽  
Plant Defense ◽  
Pseudomonas Syringae ◽  
Large Scale ◽  
Plant Cells ◽  
Defense Responses ◽  
Root Tip ◽  
General Strategy ◽  
Plant Defense Responses ◽  
Microbe Interactions

AbstractMicroorganisms that activate plant immune responses have attracted considerable attention as potential biocontrol agents in agriculture because they could reduce agrochemical use. However, conventional methods to screen for such microorganisms using whole plants and pathogens are generally laborious and time consuming. Here, we describe a general strategy using cultured plant cells to identify microorganisms that activate plant defense responses based on plant–microbe interactions. Microbial cells were incubated with tobacco BY-2 cells, followed by treatment with cryptogein, a proteinaceous elicitor of tobacco immune responses secreted by an oomycete. Cryptogein-induced production of reactive oxygen species (ROS) in BY-2 cells served as a marker to evaluate the potential of microorganisms to activate plant defense responses. Twenty-nine bacterial strains isolated from the interior of Brassica rapa var. perviridis plants were screened, and 8 strains that enhanced cryptogein-induced ROS production in BY-2 cells were selected. Following application of these strains to the root tip of Arabidopsis seedlings, two strains, Delftia sp. BR1R-2 and Arthrobacter sp. BR2S-6, were found to induce whole-plant resistance to bacterial pathogens (Pseudomonas syringae pv. tomato DC3000 and Pectobacterium carotovora subsp. carotovora NBRC 14082). Pathogen-induced expression of plant defense-related genes (PR-1, PR-5, and PDF1.2) was enhanced by the pretreatment with strain BR1R-2. This cell–cell interaction-based platform is readily applicable to large-scale screening for microorganisms that enhance plant defense responses under various environmental conditions.

scholarly journals Method for the Production and Purification of Plant Immuno-Active Xylanase from Trichoderma

2021 ◽  
Vol 22 (8) ◽  
pp. 4214
Author(s):  
Gautam Anand ◽  
Meirav Leibman-Markus ◽  
Dorin Elkabetz ◽  
Maya Bar
Keyword(s):  
Immune System ◽  
Plant Defense ◽  
Plant Immunity ◽  
Xylanase Activity ◽  
Hydrolytic Enzymes ◽  
Adaptive Immune System ◽  
Defense Responses ◽  
Plant Defense Responses ◽  
Xylanase Production ◽  
Ideal System

Plants lack a circulating adaptive immune system to protect themselves against pathogens. Therefore, they have evolved an innate immune system based upon complicated and efficient defense mechanisms, either constitutive or inducible. Plant defense responses are triggered by elicitors such as microbe-associated molecular patterns (MAMPs). These components are recognized by pattern recognition receptors (PRRs) which include plant cell surface receptors. Upon recognition, PRRs trigger pattern-triggered immunity (PTI). Ethylene Inducing Xylanase (EIX) is a fungal MAMP protein from the plant-growth-promoting fungi (PGPF)–Trichoderma. It elicits plant defense responses in tobacco (Nicotiana tabacum) and tomato (Solanum lycopersicum), making it an excellent tool in the studies of plant immunity. Xylanases such as EIX are hydrolytic enzymes that act on xylan in hemicellulose. There are two types of xylanases: the endo-1, 4-β-xylanases that hydrolyze within the xylan structure, and the β-d-xylosidases that hydrolyze the ends of the xylan chain. Xylanases are mainly synthesized by fungi and bacteria. Filamentous fungi produce xylanases in high amounts and secrete them in liquid cultures, making them an ideal system for xylanase purification. Here, we describe a method for cost- and yield-effective xylanase production from Trichoderma using wheat bran as a growth substrate. Xylanase produced by this method possessed xylanase activity and immunogenic activity, effectively inducing a hypersensitive response, ethylene biosynthesis, and ROS burst.

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