Relative specific activity (%) of VvGT14a (A), VvGT15a to VvGT15c (B), and VvGT16 (C) proteins from grape toward putative substrates as determined by radiochemical analysis with UDP-[14C]Glc. Relative activities refer to the highest levels of extractable radioactivity that were measured for the conversion of geraniol (100%) in the case of VvGT14a and VvGT15a to VvGT15c (order of columns is 15c, 15b, and 15a) and benzyl alcohol (100%) in the case of VvGT16. Data for two biological and two technical replicates are shown. Black and white bars represent monoterpenoids and nonmonoterpenoids, respectively.