Regulation of a Virus-Induced Lethal Disease in Tomato Revealed by LongSAGE Analysis

Infection of Cucumber mosaic virus (CMV) and D satellite RNA (satRNA) in tomato plants induces rapid plant death, which has caused catastrophic crop losses. We conducted long serial analysis of gene expression (LongSAGE) in control and virus-infected plants to identify the genes that may be involved in the development of this lethal tomato disease. The transcriptomes were compared between mock-inoculated plants and plants infected with CMV, CMV/D satRNA, or CMV/Dm satRNA (a nonnecrogenic mutant of D satRNA with three mutated nucleotides). The analysis revealed both general and specific changes in the tomato transcriptome after infection with these viruses. A massive transcriptional difference of approximately 400 genes was found between the transcriptomes of CMV/D and CMV/Dm satRNA-infected plants. Particularly, the Long-SAGE data indicated the activation of ethylene synthesis and signaling by CMV/D satRNA infection. Results from inoculation tests with an ethylene-insensitive mutant and treatments with an ethylene action inhibitor further confirmed the role of ethylene in mediating the epinastic leaf symptoms and the secondary cell death in the stem. Results from Northern blot analysis demonstrated the partial contribution of ethylene in the induced defense responses in CMV/D satRNA-infected plants.

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Proteomic Analysis of MeJa-Induced Defense Responses in Rice against Wounding

International Journal of Molecular Sciences ◽

10.3390/ijms20102525 ◽

2019 ◽

Vol 20 (10) ◽

pp. 2525 ◽

Cited By ~ 8

Author(s):

Laura Bertini ◽

Luana Palazzi ◽

Silvia Proietti ◽

Susanna Pollastri ◽

Giorgio Arrigoni ◽

...

Keyword(s):

Oxidative Stress ◽

Induced Defense ◽

Defense Responses ◽

Mechanical Wounding ◽

Physiological Mechanisms ◽

Profiling Techniques ◽

Protein Classes ◽

Induced Defense Responses ◽

The Impact

The role of jasmonates in defense priming has been widely recognized. Priming is a physiological process by which a plant exposed to low doses of biotic or abiotic elicitors activates faster and/or stronger defense responses when subsequently challenged by a stress. In this work, we investigated the impact of MeJA-induced defense responses to mechanical wounding in rice (Oryza sativa). The proteome reprogramming of plants treated with MeJA, wounding or MeJA+wounding has been in-depth analyzed by using a combination of high throughput profiling techniques and bioinformatics tools. Gene Ontology analysis identified protein classes as defense/immunity proteins, hydrolases and oxidoreductases differentially enriched by the three treatments, although with different amplitude. Remarkably, proteins involved in photosynthesis or oxidative stress were significantly affected upon wounding in MeJA-primed plants. Although these identified proteins had been previously shown to play a role in defense responses, our study revealed that they are specifically associated with MeJA-priming. Additionally, we also showed that at the phenotypic level MeJA protects plants from oxidative stress and photosynthetic damage induced by wounding. Taken together, our results add novel insight into the molecular actors and physiological mechanisms orchestrated by MeJA in enhancing rice plants defenses after wounding.

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

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-20-2-0146 ◽

2007 ◽

Vol 20 (2) ◽

pp. 146-158 ◽

Cited By ~ 19

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.

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A Role of Cytokinin Transporter in Arabidopsis Immunity

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-01-17-0011-r ◽

2017 ◽

Vol 30 (4) ◽

pp. 325-333 ◽

Cited By ~ 6

Author(s):

Shuai Wang ◽

Shu Wang ◽

Qi Sun ◽

Leiyun Yang ◽

Ying Zhu ◽

...

Keyword(s):

Disease Resistance ◽

Induced Defense ◽

Plant Immunity ◽

Receptor Gene ◽

Defense Responses ◽

Plant Growth And Development ◽

Immune Receptor ◽

Receptor Mutant ◽

Induced Defense Responses

The phytohormone cytokinin (CK) is not only essential for plant growth and development but also impacts plant immunity. A mutant screen in a constitutively active plant immune receptor mutant snc1 (suppressor of npr1, constitutive1) identified a suppressor mutation of SNC1-induced defense responses in an ABC transporter coding gene ABCG14. ABCG14 transports CK from roots to the shoots, and the suppression of the SNC1-mediated defense response by the loss of ABCG14 is due to a deficiency of trans-zeatin (tZ)-type CK in the shoot. In addition, exogenous application of the tZ-type CK enhances disease resistance associated with increased expression of the plant immune receptor gene SNC1. Taken together, this study further established the role of tZ-type CK in disease resistance and suggests a new intersection of CKs with plant immunity at the expression regulation of a plant immune receptor gene.

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Elicitor-Induced Defense Responses inSolanum lycopersicumagainstRalstonia solanacearum

The Scientific World JOURNAL ◽

10.1155/2013/561056 ◽

2013 ◽

Vol 2013 ◽

pp. 1-9 ◽

Cited By ~ 31

Author(s):

Sudhamoy Mandal ◽

Itishree Kar ◽

Arup K. Mukherjee ◽

Priyambada Acharya

Keyword(s):

Phenylalanine Ammonia Lyase ◽

Induced Defense ◽

Disease Incidence ◽

Cinnamyl Alcohol Dehydrogenase ◽

Defense Responses ◽

Total Phenolic ◽

Pronounced Increase ◽

Tomato Plants ◽

Alcohol Dehydrogenase Activity ◽

Induced Defense Responses

We investigated on important parameters of induced resistance in hydroponic tomato (Solanum lycopersicum) againstRalstonia solanacearumusing the elicitors chitosan (CHT), salicylic acid (SA), and jasmonic acid (JA). The increase in total phenolic content of roots by the elicitors was significantly higher than control. Most pronounced increase in lignin synthesis was triggered by SA followed by CHT. At 24 h post-elicitation (hpe), the activity of phenylalanine ammonia lyase was 4.5 times higher than control elicited by CHT. The peroxidase activity was about 86 nkat/mg protein at 24 hpe in case of SA and 78 nkat/mg protein in case of CHT. The activity of polyphenol oxidase increased several folds by the elicitors. Cinnamyl alcohol dehydrogenase activity increased to the maximum at 48 hpe under the influence of CHT. The results indicate that the elicitors SA and CHT induced effective defense responses in tomato plants againstR. solanacearum. This was evident from reduced vascular browning and wilting symptoms of tomato plants treated with SA and CHT and challenged subsequently withR. solanacearum. This reduced disease incidence in tomato by SA and CHT may be a result of cell wall strengthening through deposition of lignin and the coincident induction of defense enzymes.

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Induction of cell wall phenolic monomers as part of direct defense response in maize to pink stem borer (Sesamia inferens Walker) and non-insect interactions

Scientific Reports ◽

10.1038/s41598-021-93727-2 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

P. Lakshmi Soujanya ◽

J. C. Sekhar ◽

C. V. Ratnavathi ◽

Chikkappa G. Karjagi ◽

E. Shobha ◽

...

Keyword(s):

Induced Defense ◽

Stem Borer ◽

Defense Responses ◽

Short Term ◽

Mechanical Wounding ◽

Leaf Tissues ◽

Short And Long Term ◽

Insect Interactions ◽

Induced Defense Responses

AbstractPink stem borer (PSB) causes considerable yield losses to maize. Plant–insect interactions have significant implications for sustainable pest management. The present study demonstrated that PSB feeding, mechanical wounding, a combination of mechanical wounding and PSB regurgitation and exogenous application of methyl jasmonate have induced phenolic compound mediated defense responses both at short term (within 2 days of treatment) and long term (in 15 days of treatment) in leaf and stalk tissues of maize. The quantification of two major defense related phenolic compounds namely p-Coumaric acid (p-CA) and ferulic acid (FA) was carried out through ultra-fast liquid chromatography (UFLC) at 2 and 15 days after imposing the above treatments. The p-CA content induced in leaf tissues of maize genotypes were intrinsically higher when challenged by PSB attack at V3 and V6 stages in short- and long-term responses. Higher p-CA content was observed in stalk tissues upon wounding and regurgitation in short- and long-term responses at V3 and V6 stages. Significant accumulation of FA content was also observed in leaf tissues in response to PSB feeding at V3 stage in long-term response while at V6 stage it was observed both in short- and long-term responses. In stalk tissues, methyl jasmonate induced higher FA content in short-term response at V3 stage. However, at V6 stage PSB feeding induced FA accumulation in the short-term while, wounding and regurgitation treatment-induced defense responses in the long-term. In general, the resistant (DMRE 63, CM 500) and moderately resistant genotypes (WNZ ExoticPool) accumulated significantly higher contents of p-CA and FA content than susceptible ones (CM 202, BML 6) in most of the cases. The study indicates that phenolic mediated defense responses in maize are induced by PSB attack followed by wounding and regurgitation compared to the other induced treatments. Furthermore, the study confirmed that induced defense responses vary with plant genotype, stage of crop growth, plant tissue and short and long-term responses. The results of the study suggested that the Phenolic acids i.e. p-CA and FA may contribute to maize resistance mechanisms in the maize-PSB interaction system.

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Caterpillar salivary enzymes: "eliciting" a response

Phytoprotection ◽

10.7202/008904ar ◽

2004 ◽

Vol 85 (1) ◽

pp. 33-37 ◽

Cited By ~ 14

Author(s):

Magali Merkx-Jacques ◽

Jacqueline C. Bede

Keyword(s):

Artificial Diet ◽

Spodoptera Exigua ◽

Induced Defense ◽

Defense Responses ◽

Beet Armyworm ◽

Herbivorous Insect ◽

Plant Responses ◽

Plant Defense Responses ◽

Induced Defense Responses ◽

Bertha Armyworm

Abstract Plants exhibit remarkable plasticity in their ability to differentiate between herbivorous insect species and subtly adjust their defense responses to target distinct pests. One key mechanism used by plants to recognize herbivorous caterpillars is elicitors present in their oral secretions; however, these elicitors not only cause the induction of plant defenses but recent evidence suggests that they may also suppress plant responses. The absence of “expected changes” in induced defense responses of insect-infested plants has been attributed to hydrogen peroxide produced by caterpillar salivary glucose oxidase (GOX). Activity of this enzyme is variable among caterpillar species; it was detected in two generalist caterpillars, the beet armyworm (Spodoptera exigua) and the bertha armyworm (Mamestra configurata), but not in other generalist or specialist caterpillar species tested. In the beet armyworm, GOX activity fluctuated over larval development with high activity associated with the salivary glands of fourth instars. Larval salivary GOX activity of the beet armyworm and the bertha armyworm was observed to be significantly higher in caterpillars reared on artificial diet as compared with those reared on Medicago truncatula plants. This implies that a factor in the diet is involved in the regulation of caterpillar salivary enzyme activity. Therefore, plant diet may be regulating caterpillar oral elicitors that are involved in the regulation of plant defense responses: our goal is to understand these two processes.

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Citronella essential oil in the control and activation of coffee plants defense response against rust and brown eye spot

Ciência e Agrotecnologia ◽

10.1590/s1413-70542012000400001 ◽

2012 ◽

Vol 36 (4) ◽

pp. 383-390 ◽

Cited By ~ 5

Author(s):

Ricardo Borges Pereira ◽

Gilvaine Ciavareli Lucas ◽

Fabiano José Perina ◽

Pedro Martins Ribeiro Júnior ◽

Eduardo Alves

Keyword(s):

Essential Oil ◽

Induced Defense ◽

Defense Responses ◽

Plant Diseases ◽

Negative Effects ◽

Significant Control ◽

Citronella Oil ◽

Coffee Plants ◽

Induced Defense Responses ◽

Brown Eye Spot

The rust and brown eye spot are the main coffee diseases. The losses are due to intense defoliation of plants, which has reduced its production and longevity. The brown eye spot also occurs in fruits, with negative effects on the beverage quality. Some essential oils have presented promising results in the control of plant diseases, as an alternative to the use of fungicides. The objective of this study was to evaluate citronella essential oil in the control of rust and brown eye spot and in the activation of coffee plants defense responses. Twelve-month-old plants were sprayed with citronella oil 1000 µL L-1, acibenzolar-S-methyl 200 mg L-1 and tebuconazole fungicide 200 mg L-1. Plants were inoculated with Hemileia vastatrix and Cercospora coffeicola seven days later. The application was repeated after 30 days. Plants with five months were sprayed with the same treatments to assess the induced defense responses. Citronella oil controlled rust and brown eye spot with efficiencies of 47.2% and 29.7%, respectively, while tebuconazole presented control of 96.5% and 90.5%, respectively. Acibenzolar-S-methyl reduced brown eye spot by 55.9% and showed no significant control of rust. Citronella oil increased peroxidase and chitinase activities in five months coffee plants 336, and 24 and 336 hours after spraying, respectively. Acibenzolar-S-methyl increased peroxidase, chitinase and ββ-1,3-glucanase activities 192, 288 and 336; 24 and; 240 hours after spraying, respectively. The treatments did not increase accumulation of phenols, but a significant increase in lignin was observed in plants sprayed with citronella oil.

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