scholarly journals Low Oleic Acid-Derived Repression of Jasmonic Acid-Inducible Defense Responses Requires the WRKY50 and WRKY51 Proteins

2010 ◽  
Vol 155 (1) ◽  
pp. 464-476 ◽  
Author(s):  
Qing-Ming Gao ◽  
Srivathsa Venugopal ◽  
Duroy Navarre ◽  
Aardra Kachroo
Keyword(s):  
Oleic Acid ◽  
Jasmonic Acid ◽  
Defense Responses ◽  
Inducible Defense

scholarly journals Ectopic Expression of the Rice Lumazine Synthase Gene Contributes to Defense Responses in Transgenic Tobacco

2010 ◽  
Vol 100 (6) ◽  
pp. 573-581 ◽  
Author(s):  
Tingquan Wu ◽  
An Guo ◽  
Yanying Zhao ◽  
Xiaomeng Wang ◽  
Ying Wang ◽  
...  
Keyword(s):  
Jasmonic Acid ◽  
Transgenic Tobacco ◽  
Plant Defenses ◽  
Higher Plants ◽  
Synergistic Effects ◽  
Ectopic Expression ◽  
Defense Responses ◽  
Flavin Mononucleotide ◽  
Lumazine Synthase ◽  
Ethylene Content

Lumazine synthase (LS) catalyzes the penultimate reaction in the multistep riboflavin biosynthesis pathway, which is involved in plant defenses. Plant defenses are often subject to synergistic effects of jasmonic acid and ethylene whereas LS is a regulator of jasmonic acid signal transduction. However, little is known about whether the enzyme contributes to defense responses. To study the role of LS in plant pathogen defenses, we generated transgenic tobacco expressing the rice (Oryza sativa) LS gene, OsLS. OsLS was cloned and found to have strong identity with its homologues in higher plants and less homology to microbial orthologues. The OsLS protein localized to chloroplasts in three OsLS-expressing transgenic tobacco (LSETT) lines characterized as enhanced in growth and defense. Compared with control plants, LSETT had higher content of both riboflavin and the cofactors flavin mononucleotide and flavin adenine dinucleotide. In LSETT, jasmonic acid and ethylene were elevated, the expression of defense-related genes was induced, levels of resistance to pathogens were enhanced, and resistance was effective to viral, bacterial, and oomycete pathogens. Extents of OsLS expression correlated with increases in flavin, jasmonic acid, and ethylene content, and correlated with increases in resistance levels, suggesting a role for OsLS in defense responses.

scholarly journals Jasmonic acid control of GLABRA3 links inducible defense and trichome patterning in Arabidopsis

Development ◽  
2009 ◽  
Vol 136 (6) ◽  
pp. 1039-1048 ◽  
Author(s):  
Y. Yoshida ◽  
R. Sano ◽  
T. Wada ◽  
J. Takabayashi ◽  
K. Okada
Keyword(s):  
Jasmonic Acid ◽  
Inducible Defense ◽  
Acid Control

scholarly journals The LeATL6-Associated Ubiquitin/Proteasome System May Contribute to Fungal Elicitor-Activated Defense Response via the Jasmonic Acid-Dependent Signaling Pathway in Tomato

2007 ◽  
Vol 20 (1) ◽  
pp. 72-81 ◽  
Author(s):  
Daisuke Hondo ◽  
Shu Hase ◽  
Yoshinori Kanayama ◽  
Nobuyuki Yoshikawa ◽  
Shigehito Takenaka ◽  
...  
Keyword(s):  
Jasmonic Acid ◽  
Signaling Pathway ◽  
Ubiquitin Proteasome System ◽  
Defense Responses ◽  
Cauliflower Mosaic Virus ◽  
35S Promoter ◽  
Pythium Oligandrum ◽  
Wild Tomato ◽  
Ubiquitin Proteasome ◽  
Dependent Signaling Pathway

The expression of LeATL6, an ortholog of Arabidopsis ATL6 that encodes a RING-H2 finger protein, was induced in tomato roots treated with a cell wall protein fraction (CWP) elicitor of the biocontrol agent Pythium oligandrum. The LeATL6 protein was expressed as a fusion protein with a maltose-binding protein (MBP) in Escherichia coli, and it catalyzed the transfer of ubiquitin to the MBP moiety on incubation with ubiquitin, the ubiquitin-activating enzyme E1, and the ubiquitin-conjugating enzyme E2; this indicated that LeATL6 represents ubiquitin ligase E3. LeATL6 expression also was induced by elicitor treatment of jai1-1 mutant tomato cells in which the jasmonic acid (JA)-mediated signaling pathway was impaired; however, JA-dependent expression of the basic PR-6 and TPI-1 genes that encode proteinase inhibitor II and I, respectively, was not induced in elicitor-treated jai1-1 mutants. Furthermore, transient overexpression of LeATL6 under the control of the Cauliflower mosaic virus 35S promoter induced the basic PR6 and TPI-1 expression in wild tomato but not in the jai1-1 mutant. In contrast, LeATL6 overexpression did not activate salicylic acid-responsive acidic PR-1 and PR-2 promoters in wild tomato. These results indicated that elicitor-responsive LeATL6 probably regulates JA-dependent basic PR6 and TPI-1 gene expression in tomato. The LeATL6-associated ubiquitin/proteasome system may contribute to elicitor-activated defense responses via a JA-dependent signaling pathway in plants.

scholarly journals Rhizobacteria-Induced Priming in Arabidopsis Is Dependent on Ethylene, Jasmonic Acid, and NPR1

2007 ◽  
Vol 20 (7) ◽  
pp. 759-768 ◽  
Author(s):  
Il-Pyung Ahn ◽  
Sang-Woo Lee ◽  
Seok-Cheol Suh
Keyword(s):  
Hydrogen Peroxide ◽  
Disease Resistance ◽  
Jasmonic Acid ◽  
Expression Patterns ◽  
Defense Responses ◽  
Underlying Disease ◽  
Callose Deposition ◽  
Cellular Defense ◽  
Arabidopsis Ecotype ◽  
Hydrogen Peroxide Accumulation

A nonpathogenic rhizobacterium, Pseudomonas putida LSW17S, elicited systemic protection against Fusarium wilt and pith necrosis caused by Fusarium oxysporum f. sp. lycopersici and P. corrugata in tomato (Lycopersicon esculentum L.). LSW17S also confers disease resistance against P. syringae pv. tomato DC3000 (DC3000) on Arabidopsis ecotype Col-0. To investigate mechanisms underlying disease protection, expression patterns of defense-related genes PR1, PR2, PR5, and PDF1.2 and cellular defense responses such as hydrogen peroxide accumulation and callose deposition were investigated. LSW17S treatment exhibited the typical phenomena of priming. Strong and faster transcription of defense-related genes was induced and hydrogen peroxide or callose were accumulated in Arabidopsis treated with LSW17S and infected with DC3000. In contrast, individual actions of LSW17S and DC3000 did not elicit rapid molecular and cellular defense responses. Priming by LSW17S was translocated systemically and retained for more than 10 days. Treatment with LSW17S reduced pathogen proliferation in Arabidopsis ecotype Col-0 expressing bacterial NahG; however, npr1, etr1, and jar1 mutations impaired inhibition of pathogen growth. Cellular and molecular priming responses support these results. In sum, LSW17S primes Arabidopsis for NPR1-, ethylene-, and jasmonic acid-dependent disease resistance, and efficient molecular and cellular defense responses.

scholarly journals Expression of Castanea crenata Allene Oxide Synthase in Arabidopsis Improves the Defense to Phytophthora cinnamomi

2021 ◽  
Vol 12 ◽  
Author(s):  
Susana Serrazina ◽  
Helena Machado ◽  
Rita Lourenço Costa ◽  
Paula Duque ◽  
Rui Malhó
Keyword(s):  
Jasmonic Acid ◽  
Stress Responses ◽  
Phytophthora Cinnamomi ◽  
Functional Characterization ◽  
Defense Responses ◽  
Confocal Imaging ◽  
Allene Oxide ◽  
Allene Oxide Synthase ◽  
Castanea Crenata ◽  
Oxide Synthase

Allene oxide synthase (AOS) is a key enzyme of the jasmonic acid (JA) signaling pathway. The AOS gene was previously found to be upregulated in an Asian chestnut species resistant to infection by the oomycete Phytophthora cinnamomi (Castanea crenata), while lower expression values were detected in the susceptible European chestnut (Castanea sativa). Here, we report a genetic and functional characterization of the C. crenata AOS (CcAOS) upon its heterologous gene expression in a susceptible ecotype of Arabidopsis thaliana, which contains a single AOS gene. It was found that Arabidopsis plants expressing CcAOS delay pathogen progression and exhibit more vigorous growth in its presence. They also show upregulation of jasmonic acid and salicylic acid-related genes. As in its native species, heterologous CcAOS localized to plastids, as revealed by confocal imaging of the CcAOS-eGFP fusion protein in transgenic Arabidopsis roots. This observation was confirmed upon transient expression in Nicotiana benthamiana leaf epidermal cells. To further confirm a specific role of CcAOS in the defense mechanism against the pathogen, we performed crosses between transgenic CcAOS plants and an infertile Arabidopsis AOS knockout mutant line. It was found that plants expressing CcAOS exhibit normal growth, remain infertile but are significantly more tolerant to the pathogen than wild type plants. Together, our results indicate that CcAOS is an important player in plant defense responses against oomycete infection and that its expression in susceptible varieties may be a valuable tool to mitigate biotic stress responses.

scholarly journals The Role of Pectate Lyase and the Jasmonic Acid Defense Response in Pseudomonas viridiflava Virulence

2007 ◽  
Vol 20 (2) ◽  
pp. 146-158 ◽  
Author(s):  
Katrin Jakob ◽  
Joel M. Kniskern ◽  
Joy Bergelson
Keyword(s):  
Jasmonic Acid ◽  
Defense Response ◽  
Induced Defense ◽  
Pectate Lyase ◽  
Defense Responses ◽  
Wild Populations ◽  
Pseudomonas Viridiflava ◽  
Lyase Activity ◽  
Induced Defense Responses

Pseudomonas viridiflava is a common pathogen of Arabidopsis thaliana in wild populations, yet very little is known about mechanisms of resistance and virulence in this interaction. We examined the induced defense response of A. thaliana to several strains of P. viridiflava collected from this host by quantifying the expression of PR-1 and LOX2/PDF1.2, which serve as markers for induction of the salicylic and jasmonic acid (JA) pathways, respectively. Growth of these strains then was assessed on Col-0, the fad3/7/8 and coi1-1 mutants deficient in JA- and ethylene (ET)-induced defense responses, and the sid2-1 mutant deficient in salicylic acid-induced defense responses. All strains of P. viridiflava induced high expression of LOX2 and PDF1.2 on Col-0. In contrast, PR-1 expression was delayed and reduced relative to PDF1.2 expression. Additionally, three of four P. viridiflava strains were more virulent on fad3/7/8 relative to Col-0, whereas all strains were more virulent on coi1-1 relative to Col-0, indicating that P. viridi-flava generally may be suppressed by JA/ET-mediated defense responses. In contrast, no increase in the growth of P. viridiflava strains was observed in the sid2-1 mutant relative to Col-0. Parallel experiments were performed with the closely related P. syringae pv. tomato for comparative purposes. In addition, we assessed the role of pectate lyase and the alternative sigma factor HrpL in P. viridiflava virulence on A. thaliana and found that pectate lyase activity is correlated with virulence, whereas the removal of pectate lyase or HrpL significantly reduced virulence.

scholarly journals Duplication and transcriptional divergence of three Kunitz protease inhibitor genes that modulate insect and pathogen defenses in tea plant (Camellia sinensis)

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Junyan Zhu ◽  
Yaxian He ◽  
Xiaomei Yan ◽  
Lu Liu ◽  
Rui Guo ◽  
...  
Keyword(s):  
Jasmonic Acid ◽  
Camellia Sinensis ◽  
Acid Methyl Ester ◽  
Defense Responses ◽  
Tea Plant ◽  
High Expression ◽  
Pathogen Infection ◽  
Evolutionary Patterns ◽  
Protein Assay

AbstractKunitz protease inhibitors (KPIs) are ubiquitous in plants and act as crucial compounds in defense responses against insect attack and pathogen infection. However, the influence of gene duplication on the postdivergence of the CsKPI genes involved in biotic stresses in tea plant is not well known. Here, we identified three CsKPI genes from tea plant (Camellia sinensis) and characterized their expression and evolutionary patterns among plant species. We found that CsKPI1, CsKPI2, and CsKPI3 diverged from their common ancestor 72.94 million years ago (MYA), and the tandem duplication of CsKPI2 and CsKPI3 occurred 26.78 MYA. An in vitro protein assay showed that the three CsKPI proteins were functional and inhibited the production of p-nitroanilide (PNA) from an artificial substrate. The three CsKPI-GFP fusion proteins localized to the cytoplasm. We showed that salicylic acid (SA) and transcripts of CsKPI2 and CsKPI3 significantly accumulated after infection with Glomerella cingulata. The application of exogenous SA stimulated the high expression of both CsKPI2 and CsKPI3 by activating cis-elements within their promoters. Under Ectropis oblique attack, CsKPI1 expression and jasmonic acid (JA) levels were more abundant in both insect-damaged leaf tissues and undamaged neighboring leaves. The application of jasmonic acid methyl ester elicited high expression levels of CsKPI1, suggesting that CsKPI1 accumulation requires JA production in tea plant. The overall findings suggest that the transcriptional divergence of KPI genes after duplication led to the specialized role of CsKPI1 in the physiological response to insect stress; the functional conservation between CsKPI2 and CsKPI3 confers resistance to pathogen infection in tea plant.

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