Effect of temperature on induced systemic resistance on grape against Plasmopara viticola and on pathogen's population

Some biocontrol agents are known to induce systemic resistance (ISR) in plants reducing the severity of downy mildew disease caused by Plasmopara viticola, but little is known about the effect of temperature on this mechanism. Population genetic studies revealed a considerable diversity of P. viticola in vineyards. The aim of this study is to understand the effect of temperature on Trichoderma harzianum T39-induced systemic resistance on grape and to study the effect of temperature on populations of P. viticola. Grapevine plants treated with T39 at different temperatures are inoculated with P. viticola and biological effects are evaluated. Leaves are also collected for ISR/SAR genes expression analysis. P. viticola isolates are genotyped and phenotyped (i.e. incubation time, sporulation amount). Genotypes are co-inoculated at different temperatures and the population is analyzed with microsatellite markers and real time PCR. The results will allow a better understanding of the role of the plant and the pathogen in a view of climate change