Search results for "Mildiou"
showing 6 items of 6 documents
Are grapevine stomata involved in the elicitor-induced protection against downy mildew?
2009
Stomata, natural pores bordered by guard cells, regulate transpiration and gas exchanges between plant leaves and the atmosphere. These natural openings also constitute a way of penetration for microorganisms. In plants, the perception of potentially pathogenic microorganisms or elicitors of defense reactions induces a cascade of events, including H2O2 production, that allows the activation of defense genes, leading to defense reactions. Similar signaling events occur in guard cells in response to the perception of abscisic acid (ABA), leading to stomatal closure. Moreover, few elicitors were reported to induce stomatal closure in Arabidopsis and Vicia faba leaves. Because responses to ABA…
Soybean and casein hydrolysates induce grapevine immune responses and resistance against Plasmopara viticola
2014
International audience; Plasmopara viticola, the causal agent of grapevine downy mildew, is one of the most devastating grape pathogen in Europe and North America. Although phytochemicals are used to control pathogen infections, the appearance of resistant strains and the concern for possible adverse effects on environment and human health are increasing the search for alternative strategies. In the present investigation, we successfully tested two protein hydrolysates from soybean (soy) and casein (cas) to trigger grapevine resistance against P. viticola. On Vitis vinifera cv. Marselan plants, the application of soy and cas reduced the infected leaf surface by 76 and 63%, as compared to th…
Antimicrobial Activity of Resveratrol Analogues
2014
Stilbenes, especially resveratrol and its derivatives, have become famous for their positive effects on a wide range of medical disorders, as indicated by a huge number of published studies. A less investigated area of research is their antimicrobial properties. A series of 13 trans-resveratrol analogues was synthesized via Wittig or Heck reactions, and their antimicrobial activity assessed on two different grapevine pathogens responsible for severe diseases in the vineyard. The entire series, together with resveratrol, was first evaluated on the zoospore mobility and sporulation level of Plasmopara viticola (the oomycete responsible for downy mildew). Stilbenes displayed a spectrum of acti…
Impact of biostimulants on the resistance induction level of grapevine to downy mildew by elicitors
2018
The protection of vineyards against cryptogamic diseases such as downy mildew is mainly ensured by synthetic fungicides, which cause serious environmental and health problems. The induction of resistance by elicitors could allow to reduce their use. However, even if their efficacy is demonstrated in greenhouse conditions, it remains quite variable in field conditions. Indeed, the efficacy of an elicitor depends on the plant’s ability to respond, or more generally, on the latter’s physiological status. In this context, part of the FUI project IRIS+, the aim of this present work is to evaluate whether biostimulants, through their effect on the plant’s physiology, would be able to increase the…
Les biostimulants ont-ils un impact sur la résistance induite par des éliciteurs contre le mildiou de la vigne ?
2017
SPEINRAUBIPM DOCT; La culture de la vigne constitue un intérêt économique majeur, mais la plupart des cépages sont sensibles aux maladies cryptogamiques telles que le mildiou. Protéger les vignobles contre ces maladies requiert souvent des fongicides de synthèse dont certains posent des problèmes environnementaux et sanitaires. Une stratégie potentielle serait d’utiliser des éliciteurs, molécules capables d’activer les réactions de défenses et d’établir un état de résistance face à une future attaque d’agents pathogènes. Cette stratégie est efficace sur des vignes cultivées en serres, mais reste non maîtrisée en conditions extérieures. Notre objectif est donc d’identifier des solutions susc…