The role of stilbene phytoalexins in the resistance mechanism of grapevine against plasmopara viticola

Phytoalexins are low molecular weight antimicrobial compounds synthesized as a result of biotic or abiotic stress factors and are considered to be involved in the mechanism of resistance. Phytoalexins are produced by a wide range of plant species. In particular, the presence of stilbene phytoalexins in grapevine is of great importance in terms of positive contribution to human health, as well as resistance-inducing compounds. The stilbene phytoalexins are synthesized and accumulated only in grapevine tissues. Resveratrol, δ- viniferin, ε-viniferin, and pterostilbene as stilbenic compounds are effective against the vast majority of plant diseases. Stilbenes are produced in response to biotic elicitors caused by Plasmopara viticola and other pathogens in grapevine. Recent studies have suggested that the stilbene group compounds inhibit the mobility and germination of zoospores of Plasmopara viticola, one of the most common and destructive agent of grapevine diseases. In this review, we aim to discuss the inhibiting effect of stilbene phytoalexins and their quantities accumulated in grapevine against Plasmopara viticola.