scholarly journals Pochonia chlamydosporia Isolate PC-170-Induced Expression of Marker Genes for Defense Pathways in Tomatoes Challenged by Different Pathogens

2021 ◽  
Vol 9 (9) ◽  
pp. 1882
Author(s):  
Xia Zhuang ◽  
Jian-Long Zhao ◽  
Miao Bai ◽  
Xing-Xing Ping ◽  
Yan-Lin Li ◽  
...  
Keyword(s):  
Jasmonic Acid ◽  
Defense Responses ◽  
Systemic Resistance ◽  
Marker Genes ◽  
Root Knot Nematode ◽  
Pochonia Chlamydosporia ◽  
Susceptibility To Infection ◽  
Nematode Eggs ◽  
Mutant Lines ◽  
Ja Signaling

Pochonia chlamydosporia is a fungal parasite of nematode eggs. Studies have shown that some strains of Pochonia chlamydosporia can promote plant growth and induce plants’ systemic resistance to root-knot nematodes by colonizing in their roots. This study aimed to verify the effect of the PC-170 strain on tomato growth and systemic resistance. Split-root experiments were conducted to observe the systemic resistance induced by PC-170. To explore the defense pathway that was excited due to the colonization by PC-170, we tested the expression of marker genes for defense pathways, and used mutant lines to verify the role of plant defense pathways. Our results showed that PC-170 can colonize roots, and promotes growth. We found a role for jasmonic acid (JA) in modulating tomato colonization by PC-170. PC-170 can activate tomato defense responses to reduce susceptibility to infection by the root-knot nematode Meloidogyne incognita, and induced resistance to some pathogens in tomatoes. The marker genes of the defense pathway were significantly induced after PC-170 colonization. However, salicylic acid (SA)- and jasmonic acid (JA)-dependent defenses in roots were variable with the invasion of different pathogens. Defense pathways play different roles at different points in time. SA- and JA-dependent defense pathways were shown to cross-communicate. Different phytohormones have been involved in tomato plants’ responses against different pathogens. Our study confirmed that adaptive JA signaling is necessary to regulate PC-170 colonization and induce systemic resistance in tomatoes.

scholarly journals Suppression of Meloidogyne incognita by the Entomopathogenic Fungus Lecanicillium muscarium

Plant Disease ◽  
2018 ◽  
Vol 102 (5) ◽  
pp. 977-982 ◽  
Author(s):  
Manzoor Hussain ◽  
Miloslav Zouhar ◽  
Pavel Ryšánek
Keyword(s):  
Meloidogyne Incognita ◽  
Entomopathogenic Fungus ◽  
Biocontrol Agent ◽  
Systemic Resistance ◽  
Parasitic Nematodes ◽  
Root Knot Nematode ◽  
Egg Hatching ◽  
Positive Effects ◽  
Lecanicillium Muscarium ◽  
Nematode Eggs

The entomopathogenic fungus Lecanicillium muscarium (Petch) Zare and Gams is currently being developed as a biocontrol agent against insect pests, as well as some plant-pathogenic fungi and bacteria. Data about its activity against plant-parasitic nematodes exist, but are relatively limited. To expand this understanding, we investigated the biocontrol efficiency of three isolates of L. muscarium (Lm) against the root knot nematode, Meloidogyne incognita, in both in vitro and in vivo conditions. In our experiments, the maximum number of nematode eggs, juveniles (J2s), females, and egg masses that were parasitized were quantified after a 72-h exposure to the fungus. The isolate Lm1 was designated as the best biocontrol agent against nematode eggs as well as J2s. It showed the highest colonization of eggs and significantly decreased egg hatching events. The results from two additional isolates, Lm2 and Lm3, were also significant (P = 0.05) but less pronounced than those observed with Lm1. L. muscarium treatments had significant (P = 0.05) positive effects on plant shoot and root growth compared with the growth of control plants. These results suggest the effectiveness of the fungus may be due to either the infection of eggs and J2s, or the production of secondary metabolites that induced plant defense mechanisms and lead to systemic resistance. Our study demonstrates that L. muscarium could be used as a potential biocontrol agent against root knot nematodes.

scholarly journals Erwinia carotovora subsp. carotovora and Erwinia-Derived Elicitors HrpN and PehA Trigger Distinct but Interacting Defense Responses and Cell Death in Arabidopsis

2003 ◽  
Vol 16 (3) ◽  
pp. 179-187 ◽  
Author(s):  
Tarja Kariola ◽  
Tiina A. Palomäki ◽  
Günter Brader ◽  
E. Tapio Palva
Keyword(s):  
Erwinia Carotovora ◽  
Soft Rot ◽  
Defense Responses ◽  
Systemic Resistance ◽  
Marker Genes ◽  
Plant Responses ◽  
Virulence Determinants ◽  
Lesion Formation ◽  
Defense Gene Expression ◽  
Defense Signaling

We have used an hrp-positive strain of the soft rot pathogen Erwinia carotovora subsp. carotovora to elucidate plant responses to this bacterial necrotroph. Purified virulence determinants, harpin (HrpN) and polygalacturonase (PehA), were used as tools to facilitate this analysis. We show that HrpN elicits lesion formation in Arabidopsis and tobacco and triggers systemic resistance in Arabidopsis. Establishment of resistance is accompanied by the expression of salicylic acid (SA)-dependent, but also jasmonate/ethylene (JA/ET)-dependent, marker genes PR1 and PDF1.2, respectively, suggesting that both SA-dependent and JA/ET-dependent defense pathways are activated. Use of pathway-specific mutants and transgenic NahG plants show that both pathways are required for the induction of resistance. Arabidopsis plants treated simultaneously with both elictors PehA, known to trigger only JA/ET-dependent defense signaling, and HrpN react with accelerated and enhanced induction of the marker genes PR1 and PDF1.2 both locally and systemically. This mutual amplification of defense gene expression involves both SA-dependent and JA/ET-dependent defense signaling. The two elicitors produced by E. carotovora subsp. carotovora also cooperate in triggering increased production of superoxide and lesion formation.

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 Metabolic Control within the Jasmonate Biochemical Pathway

2019 ◽  
Vol 60 (12) ◽  
pp. 2621-2628 ◽  
Author(s):  
Thierry Heitz ◽  
Ekaterina Smirnova ◽  
Valentin Marquis ◽  
Laure Poirier
Keyword(s):  
Jasmonic Acid ◽  
Metabolic Flux ◽  
Defense Responses ◽  
Acid Oxidase ◽  
Biochemical Pathway ◽  
Cytochrome P450 Enzymes ◽  
Genetic Inactivation ◽  
Signal Output ◽  
Developmental Responses ◽  
Ja Signaling

Abstract Regulation of defense and developmental responses by jasmonates (JAs) has been intensively investigated at genetic and transcriptional levels. Plasticity in the jasmonic acid (JA) metabolic pathway as a means to control signal output has received less attention. Although the amplitude of JA responses generally follows the accumulation dynamics of the active hormone jasmonoyl-isoleucine (JA-Ile), emerging evidence has identified cases where this relationship is distorted and that we discuss in this review. JA-Ile is turned over in Arabidopsis by two inducible, intertwined catabolic pathways; one is oxidative and mediated by cytochrome P450 enzymes of the subfamily 94 (CYP94), and the other proceeds via deconjugation by amidohydrolases. Their genetic inactivation has profound effects on JAs homeostasis, including strong JA-Ile overaccumulation, but this correlates with enhanced defense and tolerance to microbial or insect attacks only in the absence of overinduction of negative signaling regulators. By contrast, the impairment of JA oxidation in the jasmonic acid oxidase 2 (jao2) mutant turns on constitutive defense responses without elevating JA-Ile levels in naive leaves and enhances resistance to subsequent biotic stress. This latter and other recent cases of JA signaling are associated with JA-Ile catabolites accumulation rather than more abundant hormone, reflecting increased metabolic flux through the pathway. Therefore, manipulating upstream and downstream JA-Ile homeostatic steps reveals distinct metabolic nodes controlling defense signaling output.

scholarly journals Transcriptional evidence for cross talk between JA and ET or SA during root-knot nematode invasion in tomato

2018 ◽  
Vol 50 (3) ◽  
pp. 197-207 ◽  
Author(s):  
Wenchao Zhao ◽  
Xiaoxuan Zhou ◽  
Hui Lei ◽  
Jingwei Fan ◽  
Rui Yang ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Expression Patterns ◽  
Defense Responses ◽  
Differentially Expressed ◽  
Root Knot Nematode ◽  
Real Time Quantitative Pcr ◽  
Copy Numbers ◽  
Transcription Factor Genes ◽  
Acid Pathway ◽  
Ja Signaling

studies have demonstrated that jasmonic acid (JA) reduces root-knot nematode (RKN) infections in tomato plants. RKN invasion is sensed by roots, and root-derived JA signaling activates systemic defense responses, though this is poorly understood. Here, we investigate variations in the RKN-induced transcriptome in scion phloem between two tomato plant grafts: CM/CM ( Lycopersicum esculentum Mill. cv. Castlemart) and CM/ spr2 (a JA-deficient mutant). A total of 8,716 genes were differentially expressed in the scion phloem of the plants with JA-deficient rootstock via RNA sequencing. Among these genes, 535 upregulated and 153 downregulated genes with high copy numbers were identified as significantly differentially expressed. Among them, 34 predicted transcription factor genes were identified. Additionally, we used real-time quantitative PCR to analyze the expression patterns of 42 genes involved in the JA, ethylene, or salicylic acid pathway in phloem under RKN infection. The results suggested that in the absence of JA signaling, the ET signaling pathway is enhanced after RKN infection; however, alterations in the SA signaling pathway were not observed.

scholarly journals The Sesquiterpene Botrydial Produced by Botrytis cinerea Induces the Hypersensitive Response on Plant Tissues and Its Action Is Modulated by Salicylic Acid and Jasmonic Acid Signaling

2011 ◽  
Vol 24 (8) ◽  
pp. 888-896 ◽  
Author(s):  
Franco Rubén Rossi ◽  
Andrés Gárriz ◽  
María Marina ◽  
Fernando Matías Romero ◽  
María Elisa Gonzalez ◽  
...  
Keyword(s):  
Salicylic Acid ◽  
Jasmonic Acid ◽  
Botrytis Cinerea ◽  
Hypersensitive Response ◽  
Defense Responses ◽  
Callose Deposition ◽  
Pathogenesis Related ◽  
Host Signaling ◽  
Related Proteins ◽  
Ja Signaling

Botrytis cinerea, as a necrotrophic fungus, kills host tissues and feeds on the remains. This fungus is able to induce the hypersensitive response (HR) on its hosts, thus taking advantage on the host's defense machinery for generating necrotic tissues. However, the identity of HR effectors produced by B. cinerea is not clear. The aim of this work was to determine whether botrydial, a phytotoxic sesquiterpene produced by B. cinerea, is able to induce the HR on plant hosts, using Arabidopsis thaliana as a model. Botrydial induced the expression of the HR marker HSR3, callose deposition, and the accumulation of reactive oxygen species and phenolic compounds. Botrydial also induced the expression of PR1 and PDF1.2, two pathogenesis-related proteins involved in defense responses regulated by salicylic acid (SA) and jasmonic acid (JA), respectively. A. thaliana and tobacco plants defective in SA signaling were more resistant to botrydial than wild-type plants, as opposed to A. thaliana plants defective in JA signaling, which were more sensitive. It can be concluded that botrydial induces the HR on its hosts and its effects are modulated by host signaling pathways mediated by SA and JA.

scholarly journals Ethylene and Jasmonic Acid Signaling Affect the NPR1-Independent Expression of Defense Genes Without Impacting Resistance to Pseudomonas syringae and Peronospora parasitica in the Arabidopsis ssi1 Mutant

2003 ◽  
Vol 16 (7) ◽  
pp. 588-599 ◽  
Author(s):  
Ashis Nandi ◽  
Pradeep Kachroo ◽  
Hirotada Fukushige ◽  
David F. Hildebrand ◽  
Daniel F. Klessig ◽  
...  
Keyword(s):  
Jasmonic Acid ◽  
Plant Defense ◽  
Pseudomonas Syringae ◽  
Defense Mechanism ◽  
Constitutive Expression ◽  
Defense Responses ◽  
Peronospora Parasitica ◽  
Defense Genes ◽  
Pr Genes ◽  
Ja Signaling

Salicylic acid (SA), ethylene, and jasmonic acid (JA) are important signaling molecules in plant defense to biotic stress. An intricate signaling network involving SA, ethylene, and JA fine tunes plant defense responses. SA-dependent defense responses in Arabidopsis thaliana are mediated through NPR1-dependent and -independent mechanisms. We have previously shown that activation of an NPR1-independent defense mechanism confers enhanced disease resistance and constitutive expression of the pathogenesis-related (PR) genes in the Arabidopsis ssi1 mutant. In addition, the ssi1 mutant constitutively expresses the defensin gene PDF1.2. Moreover, SA is required for the ssi1-conferred constitutive expression of PDF1.2 in addition to PR genes. Hence, the ssi1 mutant appears to target a step common to SA- and ethylene- or JA-regulated defense pathways. In the present study, we show that, in addition to SA, ethylene and JA signaling also are required for the ssi1-conferred constitutive expression of PDF1.2 and the NPR1-independent expression of PR-1. Furthermore, the ethylene-insensitive ein2 and JA-insensitive jar1 mutants enhance susceptibility of ssi1 plants to the necrotrophic fungus Botrytis cinerea. However, defects in either the ethylene- or JA-signaling pathways do not compromise ssi1-conferred resistance to the bacterial pathogen Pseudomonas syringae pv. maculicola and the oomycete pathogen Peronospora parasitica. Interestingly, ssi1 exhibits a marginal increase in the levels of ethylene and JA, suggesting that low endogenous levels of these phytohormones are sufficient to activate expression of defense genes. Taken together, our results indicate that although cross talk in ssi1 renders expression of ethylene- or JA-responsive defense genes sensitive to SA and vice versa, it does not affect downstream signaling leading to resistance.

scholarly journals OsJAZ11 regulates phosphate starvation responses in rice

Planta ◽  
2021 ◽  
Vol 254 (1) ◽  
Author(s):  
Bipin K. Pandey ◽  
Lokesh Verma ◽  
Ankita Prusty ◽  
Ajit Pal Singh ◽  
Malcolm J. Bennett ◽  
...  
Keyword(s):  
Jasmonic Acid ◽  
Root Length ◽  
Root Elongation ◽  
Terminal Region ◽  
Physical Interaction ◽  
Plant Signaling ◽  
Functional Connections ◽  
Growth Inhibitory ◽  
Expression Studies ◽  
Ja Signaling

Abstract Main conclusion OsJAZ11 regulates phosphate homeostasis by suppressing jasmonic acid signaling and biosynthesis in rice roots. Abstract Jasmonic Acid (JA) is a key plant signaling molecule which negatively regulates growth processes including root elongation. JAZ (JASMONATE ZIM-DOMAIN) proteins function as transcriptional repressors of JA signaling. Therefore, targeting JA signaling by deploying JAZ repressors may enhance root length in crops. In this study, we overexpressed JAZ repressor OsJAZ11 in rice to alleviate the root growth inhibitory action of JA. OsJAZ11 is a low phosphate (Pi) responsive gene which is transcriptionally regulated by OsPHR2. We report that OsJAZ11 overexpression promoted primary and seminal root elongation which enhanced Pi foraging. Expression studies revealed that overexpression of OsJAZ11 also reduced Pi starvation response (PSR) under Pi limiting conditions. Moreover, OsJAZ11 overexpression also suppressed JA signaling and biosynthesis as compared to wild type (WT). We further demonstrated that the C-terminal region of OsJAZ11 was crucial for stimulating root elongation in overexpression lines. Rice transgenics overexpressing truncated OsJAZ11ΔC transgene (i.e., missing C-terminal region) exhibited reduced root length and Pi uptake. Interestingly, OsJAZ11 also regulates Pi homeostasis via physical interaction with a key Pi sensing protein, OsSPX1. Our study highlights the functional connections between JA and Pi signaling and reveals JAZ repressors as a promising candidate for improving low Pi tolerance of elite rice genotypes.

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