Search results for "downy mildew"

Toward the Identification of Two Glycoproteins Involved in the Stomatal Deregulation of Downy Mildew–Infected Grapevine Leaves

2015

SPE Pôle IPM UB; International audience; Stomata remain abnormally opened and unresponsive to abscisic acid in grapevine leaves infected by downy mildew. This deregulation occurs from 3 days post inoculation and increases concomitantly with leaf colonization by the pathogen. Using epidermal peels, we demonstrated that the active compound involved in this deregulation is located in the apoplast. Biochemical assays showed that the active compound present in the apoplastic fluids isolated from Plasmopara viticola infected grapevine leaves (IAF) is a CysCys bridge-independent, thermostable and glycosylated protein. Fractionation guided assays based on chromatography / stomatal response and prot…

An endophytic bacillus subtilis strain protects grapevine against downy mildew by direct effect and defense stimulation

2018

National audience; Plasmopara viticola, the causal agent of grapevine downy mildew, is one of the most devastating grape pathogen. Phytochemicals are generally used to control infections, but the appearance of resistant strains and the concern for possible adverse effects on environment and human health are increasing the search for alternative strategies. Biological control has received a great deal of attention as an alternative and promising measure to control different plant diseases. Many antagonistic microorganisms, including Bacillus spp., have been exploited against different pathogens. Bacillus spp. activity results from multiple modes of action including antibiosis, competition, a…

Volatile organic compounds: a role in elicitor-induced resistance of grapevine against pathogens?

2014

International audience; As Vitis vinifera varieties are susceptible to fungal diseases, numerous chemical treatments are generally required to ensure the quantity and quality of the harvest. However, in the context of sustainable viticulture, there are increasing societal request, political incitation, and winegrowers’ awareness to reduce the use of pesticides. Among possible solutions the use of elicitors that could be included in integrated pest management or biocontrol strategies might be very promising. These bioactive compounds are able to trigger plant defences, leading to induced resistance (IR) against pathogens. Despite IR can be elicited very successfully in controlled environment…

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…

Does leaf position influence induced resistance to grape downy mildew?

2013

National audience; We observed that protection against grape downy mildew achieved by resistance inducers was higher in the adult leaf than in the younger, not fully expanded leaf. Using sulfated laminarin as inducer, this difference of efficacy could be correlated to stronger defense reactions (i. e. H2O2, defense gene expression) in adult leaf as compared to the younger one. These findings should be taken into account in disease control strategies involving induced resistance.

Impact of environmental factors on grapevine physiology and responsiveness to elicitor-induced resistance against Plasmopara viticola

2012

Sesquiterpenes VOCs are markers of elicitation by sulfated laminarine in grapevine

2016

International audience

Image analysis methods for assessment of H2O2 production and Plasmopara viticola development in grapevine leaves: application to the evaluation of re…

2014

Sesquiterpene volatile organic compounds (VOCs) are markers of elicitation by sulfated laminarine in grapevine

2015

SPE IPM UB CT1; International audience; Inducing resistance in plants by the application of elicitors of defense reactions is an attractive plant protection strategy, particularly for grapevine (Vitis vinifera), which is susceptible to severe fungal diseases. Although induced resistance (IR) can be successful under controlled conditions, in most cases, IR is not sufficiently effective for practical disease control under outdoor conditions. Progress in the application of IR requires a better understanding of grapevine defense mechanisms and the ability to monitor defense markers to identify factors, such as physiological and environmental factors, that can impact IR in the vineyard. Volatile…

Investigation of the resistance of different varieties of buckwheat to infectious diseases after the pre-sowing treatment of seeds and vegetating pla…

2016

In the work it was investigated the influence of sodium humate, biological products "Vermisol", "Vitasym" and "Bioeco-funge-1" on buckwheat lesion of Botrytis bunch rot, Downy mildew, Ascochyta blight, bacteriosis, burn virus and a complex of diseases after pre-sowing treatment of seeds and vegetating plants of Victoria, Roxolana, Kara-Dag, Rubra, Zelenokvitkova-90,Stepova, Elena, Aelita, Lada and Fagopyrum tataricum Gaertn buckwheat varieties. The prospects of these biological products use under agrocenosis conditions to protect the crops of buckwheat from the complex of diseases were shown. The highest effi- ciency identified for the drug "Bioecofunge-1" which , in addition to protecting …