Fig. 3.

Relative expression levels of the group A Vitis vinifera stilbene synthase gene family members (VvSTS1/2) and of selected members of groups C and B in the leaves of the nine grapevine genotypes of Fig. 1 collected before inoculation with Plasmopara viticola. The expression data of each gene were normalized using the geometric average of the two reference genes VvEF1α and VvSAND. Relative expression levels of the different VvSTS genes were referred to a calibrator, set to the value 1, which was represented by the gene in the nine genotypes with the lowest expression (VvSTS7/8 in the cv. Aleatico, ALE). Each reported value is the mean ± SD of three biological replicates, each of which was analyzed in triplicate. Grapevine genotypes: CHA = Chasselas, ALE = Aleatico, CAN=Canaiolo nero, TRE = Trebbiano toscano, ROS = Rossetto, ROM = Romanesco, SYL = accession of V. vinifera subsp. sylvestris, ISA = Isabella, SOL = Solaris