First Insights into the Effect of Mycorrhizae on the Expression of Pathogen Effectors during the Infection of Grapevine with Plasmopara viticola

Grapevine (Vitis vinifera L.), widely used for berry and wine production, is highly susceptible to the pathogenic oomycete Plasmopara viticola, etiological agent of grapevine downy mildew disease. The method commonly prevent control P. viticola infection relies on multiple applications chemical fungicides. However, with European Union goals lower usage such chemicals in viticulture there a need develop new more sustainable strategies. use beneficial microorganisms biocontrol capabilities, as arbuscular mycorrhizal fungi (AMF), has been pointed out viable alternative. With this study, we intended investigate effect AMF colonization expression effectors during grapevine. plants were inoculated Rhizophagus irregularis and, after mycorrhizae development, infected viticola. RxLR was analyzed by real-time PCR (qPCR) first hours interaction. Results show that pre-mycorrhizal inoculation alters several effectors; namely, PvRxLR28, which presented decreased at two time points post-infection tested. These results suggest pre-inoculation could interfere pathogen’s ability infect modulation pathogenicity expression, supporting hypothesis can be increase plant resistance pathogens promote agriculture practices, particularly viticulture.