Methyl jasmonate induced defense responses increase resistance to Fusarium oxysporum f. sp. cubense race 4 in banana

Due to apparent participation of plant lipoxygenases (LOXs) in the biosynthetic pathways for jasmonic acid, methyl jasmonate, traumatin, and several C-6 volatile compounds, LOXs are believed to have a role in senescence, plant growth and development, and wound- and pathogen-induced defense responses. Multiple functions that are ascribed to this enzyme family are in accordance with the heterogeneity of LOX isozyme forms. It is possible that different LOX isoforms may be involved in different physiological processes. In our search for a gene that encodes a LOX isozyme form specifically involved in potato defense responses against pests and pathogens, we have screened an abscisic acid-induced potato leaf cDNA library, and we have isolated, sequenced, and characterized a cDNA clone that we have designated POTLX-3. The high sequence homology of our cDNA clone to other reported plant LOX genes provided evidence that POTLX-3 is a lipoxygenase. This cDNA clone represents a novel potato LOX gene in that it shares the least nucleotide and amino acid sequence homology to other isolated potato LOX genes. Northern analysis indicated that POTLX-3 transcripts did not accumulate in untreated potato leaves, but it was highly induced by treatment with physiological levels of ethylene. Northern analysis also was performed to study whether the POTLX-3 mRNA accumulation could be induced by other plant hormones that affect expression of the other plant LOX and defense-related genes. Treatment of potato leaves with methyl jasmonate, abscisic acid, gibberellic acid, auxin (NAA), and cytokinin (BA) did not induce POTLX-3 gene expression. Because the pattern of POTLX-3 gene expression is similar to that of pathogenesis-related (PR) proteins, especially the PR-1 and PR-5 groups, we suspect that POTLX-3 may be involved specifically in ethylene-induced defense responses against pathogens.

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Methyl jasmonate-induced defense responses are associated with elevation of 1-aminocyclopropane-1-carboxylate oxidase in Lycopersicon esculentum fruit

Journal of Plant Physiology ◽

10.1016/j.jplph.2011.05.021 ◽

2011 ◽

Vol 168 (15) ◽

pp. 1820-1827 ◽

Cited By ~ 27

Author(s):

Mengmeng Yu ◽

Lin Shen ◽

Aijun Zhang ◽

Jiping Sheng

Keyword(s):

Lycopersicon Esculentum ◽

Methyl Jasmonate ◽

Induced Defense ◽

Defense Responses ◽

Induced Defense Responses

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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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