Genetic analysis of grapevine wood composition identifies glycosyltransferases involved in the biosynthesis of stilbene glycosides

A cluster of six UDP glycosyltransferase genes is linked to resveratrol-glucoside (piceid) accumulation in Vitis vinifera cane and trunk wood, with one UGT gene key for constitutive piceid in lignified tissues.

• Why it matters: Wood extractives can contribute to pathogen defense, but the genetic basis for their accumulation in grapevine wood has been poorly defined.
• What they did: Using non-targeted metabolomics in a Riesling × Gewurztraminer progeny, metabolic QTL mapping of cane and trunk extractives identified mQTLs, including one driving piceid, followed by biochemical and structural characterization of six linked UGTs.
• The result: The six UGTs show strong purifying selection, and distinct UGT genes are involved in biosynthesis of cis- and trans- piceid isomers, implying isomer-specific biological roles in grapevine.