0000000000432392
AUTHOR
Adrien Gauthier
Carbohydrates in plant immunity and plant protection: roles and potential application as foliar sprays.
International audience; Increasing interest is devoted to carbohydrates for their roles in plant immunity. Some of them are elicitors of plant defenses whereas other ones act as signaling molecules in a manner similar to phytohormones. This review first describes the main classes of carbohydrates associated to plant immunity, their role and mode of action. More precisely, the state of the art about perception of "PAMP, MAMP, and DAMP (Pathogen-, Microbe-, Damage-Associated Molecular Patterns) type" oligosaccharides is presented and examples of induced defense events are provided. A particular attention is paid to the structure/activity relationships of these compounds. The role of sugars as…
Isolation and characterization of a Vitis vinifera transcription factor, VvWRKY1, and its effect on responses to fungal pathogens in transgenic tobacco plants
International audience; Pathogen attack represents a major problem for viticulture and for agriculture in general. At present, the use of phytochemicals is more and more restrictive, and therefore it is becoming essential to control disease by having a thorough knowledge of resistance mechanisms. The present work focused on the trans-regulatory proteins potentially involved in the control of the plant defence response, the WRKY proteins. A full-length cDNA, designated VvWRKY1, was isolated from a grape berry library (Vitis vinifera L. cv. Cabernet Sauvignon). It encodes a polypeptide of 151 amino acids whose structure is characteristic of group IIc WRKY proteins. VvWRKY1 gene expression in …
Étude comparée du rôle des exsudats racinaires de pois (Pisum sativum) et de féverole (Vicia faba) durant les premières phases d’infection par Aphanomyces euteiches, agent pathogène de la pourriture racinaire du pois.
International audience
Cryptogein-Induced Anion Effluxes
Anion effluxes are amongst the earliest reactions of plant cells to elicitors of defence responses. However, their properties and their role in disease resistance remain almost unknown. We previously demonstrated that cryptogein, an elicitor of tobacco defence responses, induces a nitrate (NO(3) (-)) efflux. This efflux is an early prerequisite to the cryptogein-triggered hypersensitive response (HR). Here, we analyzed the electrophysiological properties of the elicitor-mediated NO(3) (-) efflux and clarified the mechanisms through which it contributes to cell death. Application of the discontinuous single electrode voltage-clamp technique in tobacco cells elicited with cryptogein enabled u…
ß-1,4 cellodextrins, ß-1,3 glucans and a-1,4 oligogalacturonides are potent elicitors of various defense-related responses in grapevine
International audience; Plant cell-wall degradation products can be considered as ‘microbe-induced molecular patterns’ (MIMPs) recognized through plant receptors as ‘pathogen-induced modified self’. So cell-wall oligosaccharides originating from plants can play an important role in the perception of the invading pathogen by the plant. Cellodextrins (CD) are the end-products from cellulose degradation in plant cell walls, consisting og a linear ß-(1,4) linked glucose backbone. The role of these oligosaccharides in triggering plant defense reactions has not yet been established. Here, we investigated the elicitor activity of CD oligomers in grapevine cells. We show that CD triggered induction…
Bestim network : stimulating plant health in agroécological systems
The evolution of agriculture is facing strong societal expectations. One of them is to drasticallyreduce the use of synthetic inputs and in particular of plant protection products (PPP). In response,farmers and professionals in charge of agricultural development must invent a so-called "agroecological" agriculture, by ensuring profitability and sustainability of production systems and byimplementing a combination of many levers. The BESTIM network is part of this logic and proposes theconcept of "agroecological immunity" which aims to optimize the stimulation of plant health in efficientagroecological systems. We’ve adapted the concept of ecological immunity initially described in theanimal…
The Sulfated Laminarin Triggers a Stress Transcriptome before Priming the SA- and ROS-Dependent Defenses during Grapevine's Induced Resistance against Plasmopara viticola
Grapevine (Vitis vinifera) is susceptible to many pathogens which cause significant losses to viticulture worldwide. Chemical control is available, but agro-ecological concerns have raised interest in alternative methods, especially in triggering plant immunity by elicitor treatments. The β-glucan laminarin (Lam) and its sulfated derivative (PS3) have been previously demonstrated to induce resistance in grapevine against downy mildew (Plasmopara viticola). However, if Lam elicits classical grapevine defenses such as oxidative burst, pathogenesis-related (PR)-proteins and phytoalexin production, PS3 triggered grapevine resistance via a poorly understood priming phenomenon. The aim of this st…
Elicitor and resistance-inducing activities of -1,4 cellodextrins in grapevine, comparison with -1,3 glucans and -1,4 oligogalacturonides
Cellodextrins (CD), water-soluble derivatives of cellulose composed of beta-1,4 glucoside residues, have been shown to induce a variety of defence responses in grapevine (Vitis vinifera L.) cells. The larger oligomers of CD rapidly induced transient generation of H2O2 and elevation in free cytosolic calcium, followed by a differential expression of genes encoding key enzymes of the phenylpropanoid pathway and pathogenesis-related (PR) proteins as well as stimulation of chitinase and beta-1,3 glucanase activities. Most of these defence reactions were also induced by linear beta-1,3 glucans (betaGlu) and alpha-1,4 oligogalacturonides (OGA) of different degree of polymerization (DP), but the i…