The grapevine (Vitis vinifera) LysM receptor kinases VvLYK1-1 and VvLYK1-2 mediate chitooligosaccharide-triggered immunity

Chitin, a major component of fungal cell walls, is a well-known pathogen-associated molecular pattern (PAMP) that triggers defense responses in several mammal and plant species. Here, we show that two chitooligosaccharides, chitin and chitosan, act as PAMPs in grapevine (Vitis vinifera) as they elicit immune signalling events, defense gene expression and resistance against fungal diseases. To identify their cognate receptors, the grapevine family of LysM receptor kinases (LysM-RKs) was annotated and their gene expression profiles were characterized. Phylogenetic analysis clearly distinguished three V. vinifera LysM-RKs (VvLYKs) located in the same clade as the Arabidopsis CHITIN ELICITOR RECEPTOR KINASE1 (AtCERK1), which mediates chitin-induced immune responses. The Arabidopsis mutant Atcerk1, impaired in chitin perception, was transformed with these three putative orthologous genes encoding VvLYK1-1, -2, or -3 to determine if they would complement the loss of AtCERK1 function. Our results provide evidence that VvLYK1-1 and VvLYK1-2, but not VvLYK1-3, functionally complement the Atcerk1 mutant by restoring chitooligosaccharide-induced MAPK activation and immune gene expression. Moreover, expression of VvLYK1-1 in Atcerk1 restored penetration resistance to the non-adapted grapevine powdery mildew (Erysiphe necator). On the whole, our results indicate that the grapevine VvLYK1-1 and VvLYK1-2 participate in chitin- and chitosan-triggered immunity and that VvLYK1-1 plays an important role in basal resistance against E. necator

Carbohydrates in plant immunity and plant protection: roles and potential application as foliar sprays

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 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 signaling molecules, especially in plant microbe interactions, is also presented. Secondly, the potentialities and limits of foliar sprays of carbohydrates to stimulate plant immunity for crop protection against diseases are discussed, with focus on the roles of the leaf cuticle and phyllosphere microflora.Peer reviewe

Trehalose and trehalose-6-phosphate induce stomatl movements and interfere with ABA-induced stomatal closure in grapevine

SPE Pôle IPM UBInternational audienceAims: The effects of trehalose and trehalose-6-phosphate (T6P), among other sugars, were assessed on grapevine stomatal movements. Methods and results: Epidermal peels were used to assess the effects of sugars. Low concentrations of trehalose and T6P (1 μM) induced an osmotic-independent reduction of the stomatal aperture in light conditions. Furthermore, ABA-induced stomatal closure was reduced by sugar application in association with lower accumulation of reactive oxygen species in guard cells. Similar effects, although weaker, were observed in response to the disaccharides sucrose and maltose, but not in response to the monosaccharides fructose and glucose. Conclusion: This study clearly highlights the effects of sugars, especially trehalose and T6P, on grapevine stomatal movements. Significance and impact of the study: This is the first time that such effects are described in grapevine and the results obtained provide new insights about the role of sugars on stomatal regulation at the whole plant level.Objectifs : Des sucres, en particulier le tréhalose et le tréhalose-6-phosphate (T6P), ont été étudiés pour leurs effets sur les mouvements stomatiques chez la vigne. Méthodes et résultats : Des stomates obtenus à partir d’épidermes isolés ont été utilisés pour tester ces sucres. De faibles concentrations en tréhalose et en T6P (1 μM) ont induit une réduction non osmotique de l’ouverture stomatique à la lumière. Ces sucres ont également induit une réduction de la fermeture stomatique induite par l’ABA corrélée à une plus faible accumulation de formes actives de l’oxygène dans les cellules de garde. Des effets similaires, plus faibles, ont été observés avec les disaccharides saccharose et maltose, mais pas avec les monosaccharides fructose et glucose. Conclusion: Cette étude montre un effet des sucres, en particulier le tréhalose et le T6P, sur les mouvements stomatiques chez la vigne. Signification et impact de l’étude : Les résultats sont originaux et soulignent le rôle que pourraient jouer les sucres dans la régulation stomatique chez la vigne

Seeking an apoplastic stomatal dysregulation factor - Bioassay guided fractionation and proteomic analysis of apoplastic fluids from Vitis vinifera leaves infected by Plasmopara viticola

National audienc

Bestim network : stimulating plant health in agroécological systems

National audienceThe 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 system (Sadd and Schmid-Hempel, 2009; Schulenburg et al., 2009), to the plant system placed inan agroecological context.Plant health is to be understood here in a broad sense. It covers all the physiological mechanisms thatensure the expression of an efficient immune system that protects the plant from pests and diseaseswhile guaranteeing optimal development (yield, quality) and taking into account its environment(microbiota, abiotic stresses). The objective of the BESTIM network is not limited to understanding thephysiological mechanisms involved in the application of different levers, alone or in combination, thatimpact immunity. It aims, during the 5 years of the approval period (2021 - 2025), to transfer thisknowledge from the laboratory to the field and to associate it with other alternative levers alreadyavailable or being developed to achieve redesigned cropping systems tending towards "low inputs".The RMT BESTIM brings together many organizations wishing to engage collectively in thisagroecological immunity approach: Research institute, universities, Grandes Ecoles, agriculturalHighschool, Technical Institute, R&D centers, Producers associations….You can join the network here: https://rmt-bestim.org

Cross Kingdom Immunity: The Role of Immune Receptors and Downstream Signaling in Animal and Plant Cell Death

International audienceBoth plants and animals are endowed with sophisticated innate immune systems to combat microbial attack. In these multicellular eukaryotes, innate immunity implies the presence of cell surface receptors and intracellular receptors able to detect danger signal referred as damage-associated molecular patterns (DAMPs) and pathogen-associated molecular patterns (PAMPs). Membrane-associated pattern recognition receptors (PRRs), such as Toll-like receptors (TLRs), C-type lectin receptors (CLRs), receptor-like kinases (RLKs), and receptor-like proteins (RLPs) are employed by these organisms for sensing different invasion patterns before triggering antimicrobial defenses that can be associated with a form of regulated cell death. Intracellularly, animals nucleotide-binding and oligomerization domain (NOD)-like receptors or plants nucleotide-binding domain (NBD)-containing leucine rich repeats (NLRs) immune receptors likely detect effectors injected into the host cell by the pathogen to hijack the immune signaling cascade. Interestingly, during the co-evolution between the hosts and their invaders, key cross-kingdom cell death-signaling macromolecular NLR-complexes have been selected, such as the inflammasome in mammals and the recently discovered resistosome in plants. In both cases, a regulated cell death located at the site of infection constitutes a very effective mean for blocking the pathogen spread and protecting the whole organism from invasion. This review aims to describe the immune mechanisms in animals and plants, mainly focusing on cell death signaling pathways, in order to highlight recent advances that could be used on one side or the other to identify the missing signaling elements between the perception of the invasion pattern by immune receptors, the induction of defenses or the transmission of danger signals to other cells. Although knowledge of plant immunity is less advanced, these organisms have certain advantages allowing easier identification of signaling events, regulators and executors of cell death, which could then be exploited directly for crop protection purposes or by analogy for medical research

UTILISATION D'OLIGOMÈRES D'ALGINATES POUR AMÉLIORER LA PROTECTION DES PLANTES CONTRE LES PATHOGÈNES

The invention concerns the use of alginate oligomers in sequence α(1-4)Guluronane and/or ß(1-4)Mannuronane having a DP greater than 30, as an active ingredient of biocontrol products in plants, and that may be combined with another molecules such as phytohormones, against cryptogamic diseases of plants, in particular of vine (Vitis vinifera), or to protect other species against aggressors such as pathogenic microbes or insects.L'invention concerne l'utilisation d'oligomères d'alginate dans la séquence α(1-4)Guluronane et/ou ß(1-4)Mannuronane ayant un DP supérieur à 30, en tant que principe actif de produits de lutte biologique dans des plantes, et qui peuvent être combinées avec d'autres molécules telles que des phytohormones, contre des maladies cryptogamiques de plantes, en particulier de la vigne (Vitis vinifera), ou pour protéger d'autres espèces contre des agressions telles que des microbes pathogènes ou des insectes

Bestim network : stimulating plant health in agroécological systems

National audienceThe 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 system (Sadd and Schmid-Hempel, 2009; Schulenburg et al., 2009), to the plant system placed inan agroecological context.Plant health is to be understood here in a broad sense. It covers all the physiological mechanisms thatensure the expression of an efficient immune system that protects the plant from pests and diseaseswhile guaranteeing optimal development (yield, quality) and taking into account its environment(microbiota, abiotic stresses). The objective of the BESTIM network is not limited to understanding thephysiological mechanisms involved in the application of different levers, alone or in combination, thatimpact immunity. It aims, during the 5 years of the approval period (2021 - 2025), to transfer thisknowledge from the laboratory to the field and to associate it with other alternative levers alreadyavailable or being developed to achieve redesigned cropping systems tending towards "low inputs".The RMT BESTIM brings together many organizations wishing to engage collectively in thisagroecological immunity approach: Research institute, universities, Grandes Ecoles, agriculturalHighschool, Technical Institute, R&D centers, Producers associations….You can join the network here: https://rmt-bestim.org

Induced resistance as a strategy for vineyard protection

National audienc

How Plasmopara viticola is able to alter grapevine leaf physiology

National audienc