Molecular Identification and Antifungal Properties of Four Thaumatin-like Proteins in Spruce (Picea likiangensis)

Thaumatin-like proteins (TLPs) are involved in the plant defense response against pathogens, and most of them exhibit antifungal activity. However, the role of TLPs in pathogen-induced defense responses in spruce is not fully understood. In this study, four TLP genes encoding thaumatin-like protein, designated as PlTLP1–4, were isolated and identified from Picea likiangensis needles. Sequence analysis showed that PlTLP1, PlTLP3, and PlTLP4 contained 16 conserved cysteine residues, while PlTLP2 had only 10 conserved cysteine residues. qPCR analysis showed that PlTLPs were expressed in all tissues tested, PlTLP1, PlTLP3, and PlTLP4 had the highest expression levels in young fruits, while PlTLP2 had the highest expression levels in roots. In addition, the expression levels of four PlTLPs were significantly upregulated during infection by Lophodermium piceae. Four recombinant PlTLPs expressed in Escherichia coli exhibited obvious β-1,3-glucanase activity. The antifungal activity assay showed that four recombinant PlTLPs had significant inhibitory effects on the mycelial growth of L. piceae, Fusarium proliferatum, Botrytis cinerea, and Roussoella doimaesalongensis. Microscopic observation revealed that the recombinant PlTLP1–4 induced the morphological changes of the mycelia of L. piceae, and the recombinant PlTLP2 and PlTLP3 induced the morphological changes of the mycelia of F. proliferatum and R. doimaesalongensis, while all the recombinant PlTLPs had no obvious negative effect on the morphology of B. cinerea mycelium. These results suggest that PlTLP genes may play an important role in the defense response of P. likiangensis against L. piceae invasion.

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Roles of systemic fungicide in antifungal activity and induced defense responses in rubber tree (Hevea brasiliensis) against leaf fall disease caused by Neopestalotiopsis cubana

Physiological and Molecular Plant Pathology ◽

10.1016/j.pmpp.2020.101511 ◽

2020 ◽

Vol 111 ◽

pp. 101511 ◽

Cited By ~ 3

Author(s):

Narit Thaochan ◽

Chaninun Pornsuriya ◽

Thanunchanok Chairin ◽

Anurag Sunpapao

Keyword(s):

Antifungal Activity ◽

Hevea Brasiliensis ◽

Induced Defense ◽

Rubber Tree ◽

Defense Responses ◽

Systemic Fungicide ◽

Leaf Fall ◽

Induced Defense Responses

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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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Antifungal activity of liquiritin in Phytophthora capsici comprises not only membrane-damage-mediated autophagy, apoptosis, and Ca2+ reduction but also an induced defense responses in pepper

Ecotoxicology and Environmental Safety ◽

10.1016/j.ecoenv.2020.111813 ◽

2021 ◽

Vol 209 ◽

pp. 111813

Author(s):

Peiqing Liu ◽

Yushan Cai ◽

Jinzhu Zhang ◽

Rongbo Wang ◽

Benjin Li ◽

...

Keyword(s):

Antifungal Activity ◽

Induced Defense ◽

Phytophthora Capsici ◽

Membrane Damage ◽

Defense Responses ◽

Induced Defense Responses

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Dual Effects of Plant Steroidal Alkaloids on Saccharomyces cerevisiae

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00289-06 ◽

2006 ◽

Vol 50 (8) ◽

pp. 2732-2740 ◽

Cited By ~ 67

Author(s):

Veronika Simons ◽

John P. Morrissey ◽

Maita Latijnhouwers ◽

Michael Csukai ◽

Adam Cleaver ◽

...

Keyword(s):

Saccharomyces Cerevisiae ◽

Antifungal Activity ◽

Secondary Metabolites ◽

Induced Defense ◽

Substantial Reduction ◽

Plant Secondary Metabolites ◽

Defense Responses ◽

Membrane Permeabilization ◽

Ergosterol Biosynthesis ◽

Induced Defense Responses

ABSTRACT Many plant species accumulate sterols and triterpenes as antimicrobial glycosides. These secondary metabolites (saponins) provide built-in chemical protection against pest and pathogen attack and can also influence induced defense responses. In addition, they have a variety of important pharmacological properties, including anticancer activity. The biological mechanisms underpinning the varied and diverse effects of saponins on microbes, plants, and animals are only poorly understood despite the ecological and pharmaceutical importance of this major class of plant secondary metabolites. Here we have exploited budding yeast (Saccharomyces cerevisiae) to investigate the effects of saponins on eukaryotic cells. The tomato steroidal glycoalkaloidα -tomatine has antifungal activity towards yeast, and this activity is associated with membrane permeabilization. Removal of a single sugar from the tetrasaccharide chain of α-tomatine results in a substantial reduction in antimicrobial activity. Surprisingly, the complete loss of sugars leads to enhanced antifungal activity. Experiments with α-tomatine and its aglycone tomatidine indicate that the mode of action of tomatidine towards yeast is distinct from that of α-tomatine and does not involve membrane permeabilization. Investigation of the effects of tomatidine on yeast by gene expression and sterol analysis indicate that tomatidine inhibits ergosterol biosynthesis. Tomatidine-treated cells accumulate zymosterol rather than ergosterol, which is consistent with inhibition of the sterol C24 methyltransferase Erg6p. However, erg6 and erg3 mutants (but not erg2 mutants) have enhanced resistance to tomatidine, suggesting a complex interaction of erg mutations, sterol content, and tomatidine resistance.

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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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