Application of heat-treated Lysobacter capsici AZ78 cells and its polycyclic tetramate lactams effectively controls Plasmopara viticola by stimulating grapevine defence mechanisms

Abstract: The genus Lysobacter controls a broad range of plant pathogens through diverse
modes of action, including the production of Polycyclic Tetramate Lactams (PTMs),
secondary metabolites resistant to high temperatures and exhibiting strong antifungal activity. As PTMs are stored in the cell membranes, this study investigated the efficacy of applying heat-treated cells of L. capsici AZ78 in controlling Plasmopara viticola, the causal agent of grapevine downy mildew. Moreover, it sheds light on the ability of L. capsici AZ78 cells and PTMs to stimulate defence mechanisms in grapevine plants.