Chitinase Gene Positively Regulates Hypersensitive and Defense Responses of Pepper to Colletotrichum acutatum Infection

Anthracnose caused by Colletotrichum acutatum is one of the most devastating fungal diseases of pepper (Capsicum annuum L.). The utilization of chitin-binding proteins or chitinase genes is the best option to control this disease. A chitin-binding domain (CBD) has been shown to be crucial for the innate immunity of plants and activates the hypersensitive response (HR). The CaChiIII7 chitinase gene has been identified and isolated from pepper plants. CaChiIII7 has repeated CBDs that encode a chitinase enzyme that is transcriptionally stimulated by C. acutatum infection. The knockdown of CaChiIII7 in pepper plants confers increased hypersensitivity to C. acutatum, resulting in its proliferation in infected leaves and an attenuation of the defense response genes CaPR1, CaPR5, and SAR8.2 in the CaChiIII7-silenced pepper plants. Additionally, H2O2 accumulation, conductivity, proline biosynthesis, and root activity were distinctly reduced in CaChiIII7-silenced plants. Subcellular localization analyses indicated that the CaChiIII7 protein is located in the plasma membrane and cytoplasm of plant cells. The transient expression of CaChiIII7 increases the basal resistance to C. acutatum by significantly expressing several defense response genes and the HR in pepper leaves, accompanied by an induction of H2O2 biosynthesis. These findings demonstrate that CaChiIII7 plays a prominent role in plant defense in response to pathogen infection.

Download Full-text

Xanthomonas campestris pv. vesicatoria Effector AvrBsT Induces Cell Death in Pepper, but Suppresses Defense Responses in Tomato

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-23-8-1069 ◽

2010 ◽

Vol 23 (8) ◽

pp. 1069-1082 ◽

Cited By ~ 30

Author(s):

Nak Hyun Kim ◽

Hyong Woo Choi ◽

Byung Kook Hwang

Keyword(s):

Xanthomonas Campestris ◽

Marker Gene ◽

Defense Responses ◽

Gene Expressions ◽

Callose Deposition ◽

Tomato Plants ◽

Type Iii Effector ◽

Type Iii ◽

Pepper Leaves ◽

Pepper Plants

A type III effector protein, AvrBsT, is secreted into plant cells from Xanthomonas campestris pv. vesicatoria Bv5-4a, which causes bacterial spot disease on pepper (Capsicum annuum) and tomato (Solanum lycopersicum). To define the function and recognition of AvrBsT in the two host plants, avrBsT was introduced into the virulent pepper strain X. campestris pv. vesicatoria Ds1. Expression of AvrBsT in Ds1 rendered the strain avirulent to pepper plants. Infection of pepper leaves with Ds1 (avrBsT) expressing AvrBsT but not with near-isogenic control strains triggered a hypersensitive response (HR) accompanied by strong H2O2 generation, callose deposition, and defense-marker gene expressions. Mutation of avrBsT, however, compromised HR induction by X. campestris pv. vesicatoria Bv5-4a, suggesting its avirulence function in pepper plants. In contrast, AvrBsT acted as a virulence factor in tomato plants. Growth of strains Ds1 (avrBsT) and Bv5-4a ΔavrBsT was significantly enhanced and reduced, respectively, in tomato leaves. X. campestris pv. vesicatoria-expressed AvrBsT also significantly compromised callose deposition and defense-marker gene expression in tomato plants. Together, these results suggest that the X. campestris pv. vesicatoria type III effector AvrBsT is differentially recognized by pepper and tomato plants.

Download Full-text

The PIFs Redundantly Control Plant Defense Response against Botrytis cinerea in Arabidopsis

Plants ◽

10.3390/plants9091246 ◽

2020 ◽

Vol 9 (9) ◽

pp. 1246

Author(s):

Shengyuan Xiang ◽

Songguo Wu ◽

Haiyan Zhang ◽

Minghui Mou ◽

Yanli Chen ◽

...

Keyword(s):

Botrytis Cinerea ◽

Defense Response ◽

Plant Defenses ◽

Control Plant ◽

Light Response ◽

Defense Responses ◽

Dependent Manner ◽

In The Wild ◽

Defense Response Genes ◽

Wild Type Control

Endogenous and exogenous signals are perceived and integrated by plants to precisely control defense responses. As a crucial environmental cue, light reportedly plays vital roles in plant defenses against necrotrophic pathogens. Phytochrome-interacting factor (PIF) is one of the important transcription factors which plays essential roles in photoreceptor-mediated light response. In this study, we revealed that PIFs negatively regulate plant defenses against Botrytis cinerea. Gene expression analyses showed that the expression level of a subset of defense-response genes was higher in pifq (pif1/3/4/5) mutants than in the wild-type control, but was lower in PIF-overexpressing plants. Chromatin immunoprecipitation assays proved that PIF4/5 binds directly to the ETHYLENE RESPONSE FACTOR1 (ERF1) promoter. Moreover, genetic analyses indicated that the overexpression of ERF1 dramatically rescues the susceptibility of PIF4-HA and PIF5-GFP transgenic plants, and that PIF controls the resistance to B. cinerea in a COI1- and EIN2-dependent manner. Our results provide compelling evidence that PIF, together with the jasmonate/ethylene pathway, is important for plant resistance to B. cinerea.

Download Full-text

Trichoderma-Induced Ethylene Responsive Factor MsERF105 Mediates Defense Responses in Malus sieversii

Frontiers in Plant Science ◽

10.3389/fpls.2021.708010 ◽

2021 ◽

Vol 12 ◽

Author(s):

Shida Ji ◽

Zhihua Liu ◽

Yucheng Wang

Keyword(s):

Differential Expression ◽

Defense Response ◽

Expression Profiles ◽

Membrane Integrity ◽

Defense Responses ◽

Signal Pathways ◽

Significant Differential Expression ◽

Cell Membrane Integrity ◽

Malus Sieversii ◽

Defense Response Genes

Trichoderma can induce plant hormone signal pathways mediating plant defenses, resulting in broad-spectrum resistance to phytopathogens. Herein, Malus sieversii seedlings were treated with Trichoderma biofertilizer and/or Alternaria alternata f. sp. mali, and transcriptome analysis revealed significant differential expression. There was a high similarity between the transcriptome expression profiles of Trichoderma-induced and A. alternata-infected M. sieversii samples for genes related to jasmonic acid (JA), ethylene, and salicylic acid (SA) signaling pathways. Additionally, Trichoderma biofertilizer activated numerous disease-resistant genes (ERF, NAC, bHLH, and STK) and defense response genes (DRP, ABC, and HSP). Among transcription factors, members of the ERF family were the most differentially expressed (18 ERFs), indicating that they may be closely related to defense responses. Among ERFs, differential expression of MsERF105 was the most significant (upregulated 27.6-fold compared to controls). MsERF105 was heterologously expressed in PdPap poplar (Populus davidiana × Populus alba var. pyramidalis Louche), and following infection with A. alternata (Aal), transgenic PdPap-MsERF105s plants displayed lower malondialdehyde (downregulated 41.4%) and reactive oxygen species (ROSs) levels, and higher reductase activities, especially superoxide dismutase (SOD; upregulated 77.5% compared to PdPap-ROK2 plants). Furthermore, the lesion areas of PdPap-MsERF105s leaves were significantly smaller (0.2%) than those of PdPap-ROK2 leaves (∼26.0%), and the cell membrane integrity was superior for PdPap-MsERF105s leaves. Thus, MsERF105 enhanced the resistance of PaPap poplar to Aal, presumably because MsERF105 activates the expression of PR1 and PDF1.2. In conclusion, Trichoderma biofertilizer modulated the differential expression of numerous disease resistance genes and defense response genes in M. sieversii in response to pathogen attack, and MsERF105 played important roles in this process.

Download Full-text

Deletion of the SACPD-C Locus Alters the Symbiotic Relationship Between Bradyrhizobium japonicum USDA110 and Soybean, Resulting in Elicitation of Plant Defense Response and Nodulation Defects

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-08-16-0173-r ◽

2016 ◽

Vol 29 (11) ◽

pp. 862-877 ◽

Cited By ~ 6

Author(s):

Hari B. Krishnan ◽

Alaa A. Alaswad ◽

Nathan W. Oehrle ◽

Jason D. Gillman

Keyword(s):

Plant Defense ◽

Defense Response ◽

Acyl Carrier Protein ◽

Defense Responses ◽

Nodule Development ◽

Plant Defense Response ◽

Wild Type ◽

Two Dimensional Gel Electrophoresis ◽

Symbiotic Associations ◽

Soybean Nodule

Legumes form symbiotic associations with soil-dwelling bacteria collectively called rhizobia. This association results in the formation of nodules, unique plant-derived organs, within which the rhizobia are housed. Rhizobia-encoded nitrogenase facilitates the conversion of atmospheric nitrogen into ammonia, which is utilized by the plants for its growth and development. Fatty acids have been shown to play an important role in root nodule symbiosis. In this study, we have investigated the role of stearoyl-acyl carrier protein desaturase isoform C (SACPD-C), a soybean enzyme that catalyzes the conversion of stearic acid into oleic acid, which is expressed in developing seeds and in nitrogen-fixing nodules. In-depth cytological investigation of nodule development in sacpd-c mutant lines M25 and MM106 revealed gross anatomical alteration in the sacpd-c mutants. Transmission electron microscopy observations revealed ultrastructural alterations in the sacpd-c mutants that are typically associated with plant defense response to pathogens. In nodules of two sacpd-c mutants, the combined jasmonic acid (JA) species (JA and the isoleucine conjugate of JA) were found to be reduced and 12-oxophytodienoic acid (OPDA) levels were significantly higher relative to wild-type lines. Salicylic acid levels were not significantly different between genotypes, which is divergent from previous studies of sacpd mutant studies on vegetative tissues. Soybean nodule phytohormone profiles were very divergent from those of roots, and root profiles were found to be almost identical between mutant and wild-type genotypes. The activities of antioxidant enzymes, ascorbate peroxidase, and superoxide dismutase were also found to be higher in nodules of sacpd-c mutants. PR-1 gene expression was extremely elevated in M25 and MM106, while the expression of nitrogenase was significantly reduced in these sacpd-c mutants, compared with the parent ‘Bay’. Two-dimensional gel electrophoresis and matrix-assisted laser desorption-ionization time of flight mass spectrometry analyses confirmed sacpd-c mutants also accumulated higher amounts of pathogenesis-related proteins in the nodules. Our study establishes a major role for SACPD-C activity as essential for proper maintenance of soybean nodule morphology and physiology and indicates that OPDA signaling is likely to be involved in attenuation of nodule biotic defense responses.

Download Full-text

Morphological and Molecular Analyses of Host and Nonhost Interactions Involving Barley and Wheat and the Covered Smut Pathogen Ustilago hordei

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-11-09-0271 ◽

2010 ◽

Vol 23 (12) ◽

pp. 1619-1634 ◽

Cited By ~ 14

Author(s):

Denis A. Gaudet ◽

Yuanyuan Wang ◽

Carolyn Penniket ◽

Z. X. Lu ◽

Guus Bakkeren ◽

...

Keyword(s):

Lipid Transfer Protein ◽

Expression Patterns ◽

Fluorescent Microscopy ◽

Defense Responses ◽

Lipid Transfer ◽

Defense Gene Expression ◽

Basal Resistance ◽

Morphological Defense ◽

Pathway Expression ◽

Ustilago Hordei

Ustilago hordei interactions on coleoptiles of barley host cultivars Odessa (compatible), Hannchen (incompatible, carrying the Ruh1 resistance gene), and on nonhost Neepawa wheat were studied using light and fluorescent microscopy. Autofluorescence, mainly caused by callose accumulation, was more rapidly expressed in nonhost wheat at 30 to 72 h compared with the incompatible reaction between 72 and 144 h. Microarray results demonstrated that more than half of the 893 differentially regulated genes were observed in Neepawa; of these genes, 45% fell into the defense- and stress-related classes in Neepawa compared with 25 and 37% in Odessa and Hannchen, respectively. Their expression coincided with the early morphological defense responses observed and were associated with the jasmonic acid and ethylene (JA/ET) signaling pathway. Expression patterns in Odessa and Hannchen were similar, involving fewer genes and coinciding with later morphological defense responses of these varieties. Although no visible hypersensitive response was apparent in Hannchen or Neepawa, specific upregulation of hypersensitivity-related proteins was observed, such as beta-VPE at 48 h. Expression levels of the callose synthase gene were closely associated with callose accumulation. Differential responses in defense-gene expression among disease reaction types included upregulation of PR-1.1b and downregulation of a nonspecific lipid transfer protein in the incompatible and compatible interactions, respectively. Transcript levels of EDS1 and PAD4, involved in both basal resistance and R-mediated resistance to avirulent pathogens, were up-regulated during both nonhost and Ruh1-mediated resistance. Application of methyl-jasmonate, salicylic acid and ET to leaves revealed that only PR1.1b is strongly up-regulated by all three compounds, while the majority of the defense-related genes are only slightly up-regulated by these signaling compounds.

Download Full-text

Transcriptomic Analysis of Arabidopsis Seedlings in Response to an Agrobacterium-Mediated Transformation Process

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-10-17-0249-r ◽

2018 ◽

Vol 31 (4) ◽

pp. 445-459 ◽

Cited By ~ 5

Author(s):

Kaixuan Duan ◽

Christopher J. Willig ◽

Joann R. De Tar ◽

William G. Spollen ◽

Zhanyuan J. Zhang

Keyword(s):

Agrobacterium Tumefaciens ◽

Defense Response ◽

Time Course ◽

Basic Research ◽

Defense Responses ◽

Transformation Process ◽

Host Responses ◽

Nucleic Acid Metabolism ◽

Agrobacterium Strain ◽

Agrobacterium Mediated Transformation

Agrobacterium tumefaciens is a plant pathogen that causes crown gall disease. This pathogen is capable of transferring the T-DNA from its Ti plasmid to the host cell and, then, integrating it into the host genome. To date, this genetic transformation ability has been harnessed as the dominant technology to produce genetically modified plants for both basic research and crop biotechnological applications. However, little is known about the interaction between Agrobacterium tumefaciens and host plants, especially the host responses to Agrobacterium infection and its associated factors. We employed RNA-seq to follow the time course of gene expression in Arabidopsis seedlings infected with either an avirulent or a virulent Agrobacterium strain. Gene Ontology analysis indicated many biological processes were involved in the Agrobacterium-mediated transformation process, including hormone signaling, defense response, cellular biosynthesis, and nucleic acid metabolism. RNAseq and quantitative reverse transcription-polymerase chain reaction results indicated that expression of genes involved in host plant growth and development were repressed but those involved in defense response were induced by Agrobacterium tumefaciens. Further analysis of the responses of transgenic Arabidopsis lines constitutively expressing either the VirE2 or VirE3 protein suggested Vir proteins act to enhance plant defense responses in addition to their known roles facilitating T-DNA transformation.

Download Full-text

The defense response of Caenorhabditis elegans to Cutibacterium acnes SK137 via the TIR-1-p38 MAPK signaling pathway

Bioscience Biotechnology and Biochemistry ◽

10.1093/bbb/zbab218 ◽

2021 ◽

Author(s):

Ayano Tsuru ◽

Yumi Hamazaki ◽

Shuta Tomida ◽

Mohammad Shaokat Ali ◽

Eriko Kage-Nakadai

Keyword(s):

Caenorhabditis Elegans ◽

Signaling Pathway ◽

P38 Mapk ◽

Defense Response ◽

Mapk Pathway ◽

Defense Responses ◽

Mapk Signaling ◽

Dependent Manner ◽

Healthy Skin ◽

Cutibacterium Acnes

Abstract Cutibacterium acnes plays roles in both acne disease and healthy skin ecosystem. We observed that mutations in the tir-1/SARM1 and p38 MAPK cascade genes significantly shortened Caenorhabditis elegans lifespan upon Cutibacterium acnes SK137 infection. Antimicrobial molecules were induced by SK137 in a TIR-1-dependent manner. These results suggest that defense responses against SK137 involve the TIR-1-p38 MAPK pathway in Caenorhabditis elegans.

Download Full-text

A Faster and a Stronger Defense Response: One of the Key Elements in Grapevine Explaining Its Lower Level of Susceptibility to Esca?

Phytopathology ◽

10.1094/phyto-11-12-0305-r ◽

2013 ◽

Vol 103 (10) ◽

pp. 1028-1034 ◽

Cited By ~ 17

Author(s):

Carole Lambert ◽

Ian Li Kim Khiook ◽

Sylvia Lucas ◽

Nadège Télef-Micouleau ◽

Jean-Michel Mérillon ◽

...

Keyword(s):

Defense Response ◽

Defense Mechanisms ◽

Defense Responses ◽

Cabernet Sauvignon ◽

Susceptible Cultivar ◽

Pathogenesis Related ◽

Leaf Level ◽

Plant Pathogen Interaction ◽

Related Proteins ◽

Stilbene Compounds

Wood diseases like Esca are among the most damaging afflictions in grapevine. The defense mechanisms in this plant–pathogen interaction are not well understood. As some grapevine cultivars have been observed to be less susceptible to Esca than others, understanding the factors involved in this potentially stronger defense response can be of great interest. To lift part of this veil, we elicited Vitis vinifera plants of two cultivars less susceptible to Esca (‘Merlot’ and ‘Carignan’) and of one susceptible cultivar (‘Cabernet Sauvignon’), and monitored their defense responses at the leaf level. Our model of elicitation consisted in grapevine cuttings absorbing a culture filtrate of one causal agent of Esca, Phaemoniella chlamydospora. This model might reflect the early events occurring in Esca-affected grapevines. The two least susceptible cultivars showed an earlier and stronger defense response than the susceptible one, particularly with regard to induction of the PAL and STS genes, and a higher accumulation of stilbene compounds and some pathogenesis-related proteins.

Download Full-text

BAX INHIBITOR-1 Is Required for Full Susceptibility of Barley to Powdery Mildew

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-23-9-1217 ◽

2010 ◽

Vol 23 (9) ◽

pp. 1217-1227 ◽

Cited By ~ 58

Author(s):

Ruth Eichmann ◽

Melanie Bischof ◽

Corina Weis ◽

Jane Shaw ◽

Christophe Lacomme ◽

...

Keyword(s):

Cell Death ◽

Powdery Mildew ◽

Gene Silencing ◽

Defense Responses ◽

Negative Control ◽

Cellular Level ◽

Virus Induced Gene Silencing ◽

Powdery Mildew Fungus ◽

Basal Resistance ◽

Enhanced Resistance

BAX INHIBITOR-1 (BI-1) is one of the few proteins known to have cross-kingdom conserved functions in negative control of programmed cell death. Additionally, barley BI-1 (HvBI-1) suppresses defense responses and basal resistance to the powdery mildew fungus Blumeria graminis f. sp. hordei and enhances resistance to cell death–provoking fungi when overexpressed in barley. Downregulation of HvBI-1 by transient-induced gene silencing or virus-induced gene silencing limited susceptibility to B. graminis f. sp. hordei, suggesting that HvBI-1 is a susceptibility factor toward powdery mildew. Transient silencing of BI-1 did not limit supersusceptibility induced by overexpression of MLO. Transgenic barley plants harboring an HvBI-1 RNA interference (RNAi) construct displayed lower levels of HvBI-1 transcripts and were less susceptible to powdery mildew than wild-type plants. At the cellular level, HvBI-1 RNAi plants had enhanced resistance to penetration by B. graminis f. sp. hordei. These data support a function of BI-1 in modulating cell-wall-associated defense and in establishing full compatibility of B. graminis f. sp. hordei with barley.

Download Full-text

Using physiological signals to predict temporal defense responses: a multi-modality analysis

10.1101/2020.12.17.423337 ◽

2020 ◽

Author(s):

Tae-jun Choi ◽

Honggu Lee

Keyword(s):

Defense Response ◽

Defense Responses ◽

Physiological Signals ◽

Classification Model ◽

Post Traumatic Stress ◽

Obsessive Compulsive ◽

Compulsive Disorder ◽

Novel Approach ◽

Data Driven Approach ◽

Response Classification

AbstractDefense responses are a highly conserved behavioral response set across species. Defense responses motivate organisms to detect and react to threats and potential danger as a precursor to anxiety. Accurate measurement of temporal defense responses is important for understanding clinical anxiety and mood disorders, such as post-traumatic stress disorder, obsessive compulsive disorder, and generalized anxiety disorder. Within these conditions, anxiety is defined as a state of prolonged defense response elicitation to a threat that is ambiguous or unspecific. In this study, we aimed to develop a data-driven approach to capture temporal defense response elicitation through a multi-modality data analysis of physiological signals, including electroencephalogram (EEG), electrocardiogram (ECG), and eye-tracking information. A fear conditioning paradigm was adopted to develop a defense response classification model. From a classification model based on 42 feature sets, a higher order crossing feature set-based model was chosen for further analysis with cross-validation loss of 0.0462 (SEM: 0.0077). To validate our model, we compared predicted defense response occurrence ratios from a comprehensive situation that generates defense responses by watching movie clips with fear awareness and threat existence predictability, which have been reported to correlate with defense response elicitation in previous studies. We observed that defense response occurrence ratios are correlated with threat existence predictability, but not with fear awareness. These results are similar to those of previous studies using comprehensive situations. Our study provides insight into measurement of temporal defense responses via a novel approach, which can improve understanding of anxiety and related clinical disorders for neurobiological and clinical researchers.

Download Full-text