Elicitor Recognition and Signal Transduction in Plant Defense Gene Activation

1990 ◽  
Vol 45 (6) ◽  
pp. 569-575 ◽  
Author(s):  
Dierk Scheel ◽  
Jane E. Parker
Keyword(s):  
Signal Transduction ◽  
Plant Defense ◽  
Transcriptional Activation ◽  
Molecular Mechanisms ◽  
Plant Protection ◽  
Plant Cells ◽  
Defense Responses ◽  
Plant Defense Responses ◽  
Defense Genes ◽  
Plant Defense Genes

Abstract Plants defend themselves against pathogen attack by activating a whole set of defense responses, most of them relying on transcriptional activation of plant defense genes. The same responses are induced by treatment of plant cells with elicitors released from the pathogen or from the plant surface. Several plant/elicitor combinations have been used successfully as experimental systems to investigate the molecular basis of plant defense responses. Receptor-like structures on the plasma membrane of plant cells appear to bind the elicitors. Thereby, intracellular signal transduction chains are initiated which finally result in the activation of plant defense genes. A better understanding of the molecular mechanisms of early processes in plant defense responses, as provided by these studies, may in the long term help to develop environmentally safe plant protection methods for agriculture.

scholarly journals Transcriptional activation of plant defense genes by fungal elicitor, wounding, and infection.

1987 ◽  
Vol 7 (1) ◽  
pp. 335-341 ◽  
Author(s):  
M A Lawton ◽  
C J Lamb
Keyword(s):  
Plant Defense ◽  
Transcriptional Activation ◽  
Gene Activation ◽  
Defense Responses ◽  
Colletotrichum Lindemuthianum ◽  
Defense Genes ◽  
Plant Defense Genes ◽  
Elicitor Treatment ◽  
Stimulation Of

Activation of plant defense genes was investigated by analysis of transcripts completed in vitro by isolated nuclei. Elicitor treatment of suspension-cultured bean (Phaseolus vulgaris L.) cells caused marked transient stimulation of transcription of genes encoding apoproteins of cell wall hydroxyproline-rich glycoproteins (HRGP) and the phenylpropanoid biosynthetic enzymes phenylalanine ammonia-lyase (PAL) and chalcone synthase (CHS), concomitant with the onset of rapid accumulation of the respective mRNAs and hence expression of the phytoalexin (PAL, CHS), lignin (PAL), and HRGP defense responses. While there was a lag of 2 h prior to stimulation of HRGP gene transcription, induction of the transcription of PAL and CHS genes occurred within 5 min of elicitor treatment. Induction of transcription of PAL, CHS, and HRGP genes was also observed in wounded hypocotyls and in infected hypocotyls during race-cultivar-specific interactions with the fungus Colletotrichum lindemuthianum, the causal agent of anthracnose. Transcriptional activation occurred not only in directly infected tissue but also in distant, hitherto uninfected tissue, indicating intercellular transmission of an endogenous signal for defense gene activation. It is concluded that transcriptional activation of defense genes characteristically underlies induction of the corresponding defense responses and expression of disease resistance.

Transcriptional activation of plant defense genes by fungal elicitor, wounding, and infection

1987 ◽  
Vol 7 (1) ◽  
pp. 335-341
Author(s):  
M A Lawton ◽  
C J Lamb
Keyword(s):  
Plant Defense ◽  
Transcriptional Activation ◽  
Gene Activation ◽  
Defense Responses ◽  
Colletotrichum Lindemuthianum ◽  
Defense Genes ◽  
Plant Defense Genes ◽  
Elicitor Treatment ◽  
Stimulation Of

Activation of plant defense genes was investigated by analysis of transcripts completed in vitro by isolated nuclei. Elicitor treatment of suspension-cultured bean (Phaseolus vulgaris L.) cells caused marked transient stimulation of transcription of genes encoding apoproteins of cell wall hydroxyproline-rich glycoproteins (HRGP) and the phenylpropanoid biosynthetic enzymes phenylalanine ammonia-lyase (PAL) and chalcone synthase (CHS), concomitant with the onset of rapid accumulation of the respective mRNAs and hence expression of the phytoalexin (PAL, CHS), lignin (PAL), and HRGP defense responses. While there was a lag of 2 h prior to stimulation of HRGP gene transcription, induction of the transcription of PAL and CHS genes occurred within 5 min of elicitor treatment. Induction of transcription of PAL, CHS, and HRGP genes was also observed in wounded hypocotyls and in infected hypocotyls during race-cultivar-specific interactions with the fungus Colletotrichum lindemuthianum, the causal agent of anthracnose. Transcriptional activation occurred not only in directly infected tissue but also in distant, hitherto uninfected tissue, indicating intercellular transmission of an endogenous signal for defense gene activation. It is concluded that transcriptional activation of defense genes characteristically underlies induction of the corresponding defense responses and expression of disease resistance.

scholarly journals An efficient direct screening system for microorganisms that activate plant immune responses based on plant–microbe interactions using cultured plant cells

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mari Kurokawa ◽  
Masataka Nakano ◽  
Nobutaka Kitahata ◽  
Kazuyuki Kuchitsu ◽  
Toshiki Furuya
Keyword(s):  
Immune Responses ◽  
Plant Defense ◽  
Pseudomonas Syringae ◽  
Large Scale ◽  
Plant Cells ◽  
Defense Responses ◽  
Root Tip ◽  
General Strategy ◽  
Plant Defense Responses ◽  
Microbe Interactions

AbstractMicroorganisms that activate plant immune responses have attracted considerable attention as potential biocontrol agents in agriculture because they could reduce agrochemical use. However, conventional methods to screen for such microorganisms using whole plants and pathogens are generally laborious and time consuming. Here, we describe a general strategy using cultured plant cells to identify microorganisms that activate plant defense responses based on plant–microbe interactions. Microbial cells were incubated with tobacco BY-2 cells, followed by treatment with cryptogein, a proteinaceous elicitor of tobacco immune responses secreted by an oomycete. Cryptogein-induced production of reactive oxygen species (ROS) in BY-2 cells served as a marker to evaluate the potential of microorganisms to activate plant defense responses. Twenty-nine bacterial strains isolated from the interior of Brassica rapa var. perviridis plants were screened, and 8 strains that enhanced cryptogein-induced ROS production in BY-2 cells were selected. Following application of these strains to the root tip of Arabidopsis seedlings, two strains, Delftia sp. BR1R-2 and Arthrobacter sp. BR2S-6, were found to induce whole-plant resistance to bacterial pathogens (Pseudomonas syringae pv. tomato DC3000 and Pectobacterium carotovora subsp. carotovora NBRC 14082). Pathogen-induced expression of plant defense-related genes (PR-1, PR-5, and PDF1.2) was enhanced by the pretreatment with strain BR1R-2. This cell–cell interaction-based platform is readily applicable to large-scale screening for microorganisms that enhance plant defense responses under various environmental conditions.

scholarly journals Foliar Application or Seed Priming of Cholic Acid-Glycine Conjugates can Mitigate/Prevent the Rice Bacterial Leaf Blight Disease via Activating Plant Defense Genes

2021 ◽  
Vol 12 ◽  
Author(s):  
Garima Pal ◽  
Devashish Mehta ◽  
Saurabh Singh ◽  
Kalai Magal ◽  
Siddhi Gupta ◽  
...  
Keyword(s):  
Plant Defense ◽  
Cholic Acid ◽  
Foliar Application ◽  
Bacterial Load ◽  
Crop Protection ◽  
Seed Priming ◽  
Defense Responses ◽  
Defense Genes ◽  
Plant Defense Genes ◽  
Blight Disease

Xanthomonas Oryzae pv. oryzae (Xoo) causes bacterial blight and Rhizoctonia solani (R. solani) causes sheath blight in rice accounting for >75% of crop losses. Therefore, there is an urgent need to develop strategies for the mitigation of these pathogen infections. In this study, we report the antimicrobial efficacy of Cholic Acid-Glycine Conjugates (CAGCs) against Xoo and R. solani. We show that CAGC C6 is a broad-spectrum antimicrobial and is also able to degrade biofilms. The application of C6 did not hamper plant growth and showed minimal effect on the plant cell membranes. Exogenous application of C6 on pre-infection or post-infection of Xoo on rice susceptible genotype Taichung native (TN1) can mitigate the bacterial load and improve resistance through upregulation of plant defense genes. We further demonstrate that C6 can induce plant defense responses when seeds were primed with C6 CAGC. Therefore, this study demonstrates the potential of CAGCs as effective antimicrobials for crop protection that can be further explored for field applications.

scholarly journals The grapevine R2R3-type MYB transcription factor VdMYB1 positively regulates defense responses by activating the stilbene synthase gene 2 (VdSTS2)

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Yihe Yu ◽  
Dalong Guo ◽  
Guirong Li ◽  
Yingjun Yang ◽  
Guohai Zhang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
Transcriptional Activation ◽  
Molecular Mechanisms ◽  
Plant Protection ◽  
Defense Responses ◽  
Stilbene Synthase ◽  
Myb Transcription Factor ◽  
Wide Range ◽  
Grapevine Leaves

Abstract Background Resveratrol is a naturally occurring plant stilbene that exhibits a wide range of valuable biological and pharmacological properties. Although the beneficial effects of trans-resveratrol to human health and plant protection against fungal pathogens and abiotic stresses are well-established, yet little is known about the molecular mechanisms regulating stilbene biosynthesis in plant defense progress. Results Here, we cloned and identified the Chinese wild grape (Vitis davidii) R2R3-MYB transcription factor VdMYB1, which activates defense responses against invading pathogen. VdMYB1 transcripts were significantly upregulated after inoculation with the grapevine powdery mildew fungus Erysiphe necator (Schw.) Burr. Transient expression analysis using onion epidermal cells and Arabidopsis thaliana protoplasts showed that VdMYB1 was localized in the nucleus. Yeast one-hybrid assays revealed that VdMYB1 acts as a transcriptional activator. Grapevine leaves transiently overexpressing VdMYB1 showed a lower number of fungal conidiophores compared with wild-type leaves. Overexpression of VdMYB1 in grapevine leaves did not alter the expression of genes in salicylic acid- and jasmonate-dependent pathways, but affected the expression of stilbene synthase (STS) genes, key regulators of flavonoid metabolism. Results of electrophoretic mobility shift assays and in vivo transcriptional activation assays showed that VdMYB1 binds to the MYB binding site (MYBBS) in the STS2 gene promoter, thus activating STS2 transcription. In heterologous expression assays using tobacco leaves, VdMYB1 activated STS2 gene expression and increased the accumulation of resveratrol. Conclusions Our study showed that VdMYB1 activates STS2 gene expression to positively regulate defense responses, and increases the content of resveratrol in leaves.

A Putative Role for Fusaric Acid in Biocontrol of the Parasitic Angiosperm Orobanche ramosa

2006 ◽  
Vol 19 (5) ◽  
pp. 550-556 ◽  
Author(s):  
Brahim Bouizgarne ◽  
Hayat El-Maarouf-Bouteau ◽  
Karine Madiona ◽  
Bernadette Biligui ◽  
Michèle Monestiez ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Plant Defense ◽  
Fusaric Acid ◽  
Root Hairs ◽  
Signal Transduction Pathway ◽  
Defense Responses ◽  
Plant Defense Responses ◽  
Fusarium Spp ◽  
Membrane Hyperpolarization ◽  
Orobanche Ramosa

Fusarium spp. are ubiquitous fungi found in soil worldwide as both pathogenic and nonpathogenic strains. The signals leading to disease or the absence of disease are poorly understood. We recently showed that fusaric acid (FA), a nonspecific toxin produced by most Fusarium spp., could elicit various plant defense responses at 100 nM without toxic effect. In this study, we checked for the effect of FA on root and root hairs, probable first site of contact between the fungi and the host. Large FA concentrations reduce root and root-hair growth and induce a rapid transient membrane hyperpolarization, followed by a large depolarization, due to the inhibition of H+-ATPase currents. Nanomolar concentrations of FA induced only an early transient membrane hyperpolarization of root hairs compatible with the induction of a signal transduction pathway. FA at 10-7 M failed to induce salicylic acid- and jasmonic acid/ethylene-dependent defense-related genes but inhibited the germination of the angiosperm parasite Orobanche ramosa in contact of FA-pretreated Arabidopsis thaliana seedlings. These data suggest that FA at nontoxic concentrations could activate signal transduction components necessary for plant-defense responses that could contribute to biocontrol activity of Fusarium spp.

scholarly journals An Immuno-Suppressive Aphid Saliva Protein Is Delivered into the Cytosol of Plant Mesophyll Cells During Feeding

2016 ◽  
Vol 29 (11) ◽  
pp. 854-861 ◽  
Author(s):  
Sam T. Mugford ◽  
Elaine Barclay ◽  
Claire Drurey ◽  
Kim C. Findlay ◽  
Saskia A. Hogenhout
Keyword(s):  
Plant Defense ◽  
Plant Cells ◽  
Defense Responses ◽  
Plant Responses ◽  
Plant Defense Responses ◽  
Mesophyll Cells ◽  
Virulence Proteins ◽  
Feeding Sites ◽  
Ultrathin Sections ◽  
Aphid Feeding

Herbivore selection of plant hosts and plant responses to insect colonization have been subjects of intense investigations. A growing body of evidence suggests that, for successful colonization to occur, (effector/virulence) proteins in insect saliva must modulate plant defense responses to the benefit of the insect. A range of insect saliva proteins that modulate plant defense responses have been identified, but there is no direct evidence that these proteins are delivered into specific plant tissues and enter plant cells. Aphids and other sap-sucking insects of the order Hemiptera use their specialized mouthparts (stylets) to probe plant mesophyll cells until they reach the phloem cells for long-term feeding. Here, we show, by immunogold-labeling of ultrathin sections of aphid feeding sites, that an immuno-suppressive aphid effector localizes in the cytoplasm of mesophyll cells near aphid stylets but not in cells further away from aphid feeding sites. In contrast, another aphid effector protein localizes in the sheaths composed of gelling saliva that surround the aphid stylets. Thus, insects deliver effectors directly into plant tissue. Moreover, different aphid effectors locate extracellularly in the sheath saliva or are introduced into the cytoplasm of plant cells. [Formula: see text] Copyright © 2016 The Author(s). This is an open-access article distributed under the CC BY-NC-ND 4.0 International license .

scholarly journals The Versatile Roles of Sulfur-Containing Biomolecules in Plant Defense—A Road to Disease Resistance

Plants ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1705
Author(s):  
András Künstler ◽  
Gábor Gullner ◽  
Attila L. Ádám ◽  
Judit Kolozsváriné Kolozsváriné Nagy ◽  
Lóránt Király
Keyword(s):  
Signal Transduction ◽  
Disease Resistance ◽  
Plant Defense ◽  
Plant Disease Resistance ◽  
Defense Responses ◽  
Plant Defense Responses ◽  
Defense Compounds ◽  
Protein Functions ◽  
Sulfur Containing

Sulfur (S) is an essential plant macronutrient and the pivotal role of sulfur compounds in plant disease resistance has become obvious in recent decades. This review attempts to recapitulate results on the various functions of sulfur-containing defense compounds (SDCs) in plant defense responses to pathogens. These compounds include sulfur containing amino acids such as cysteine and methionine, the tripeptide glutathione, thionins and defensins, glucosinolates and phytoalexins and, last but not least, reactive sulfur species and hydrogen sulfide. SDCs play versatile roles both in pathogen perception and initiating signal transduction pathways that are interconnected with various defense processes regulated by plant hormones (salicylic acid, jasmonic acid and ethylene) and reactive oxygen species (ROS). Importantly, ROS-mediated reversible oxidation of cysteine residues on plant proteins have profound effects on protein functions like signal transduction of plant defense responses during pathogen infections. Indeed, the multifaceted plant defense responses initiated by SDCs should provide novel tools for plant breeding to endow crops with efficient defense responses to invading pathogens.

Involvement of plasma membrane proteins in plant defense responses. Analysis of the cryptogein signal transduction in tobacco

Biochimie ◽  
1999 ◽  
Vol 81 (6) ◽  
pp. 663-668 ◽  
Author(s):  
Angela Lebrun-Garcia ◽  
Stéphane Bourque ◽  
Marie-Noëlle Binet ◽  
Fatma Ouaked ◽  
David Wendehenne ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Plasma Membrane ◽  
Membrane Proteins ◽  
Plant Defense ◽  
Defense Responses ◽  
Plant Defense Responses ◽  
Plasma Membrane Proteins
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