Metabolic engineering of volatile isoprenoids in grapevine
Grapevine deoxyxylulose phosphate synthase (VvDXS) was reported as a positional candidate gene for muscat flavor having been co-localized with a major QTL for monoterpenoids in berries. Recently a putative causal SNP responsible for a non-neutral substitution in the VvDXS1 protein was found to be significantly associated with muscat flavored varieties and a functional effect of this polymorphism was proven in transgenic tobacco adopting a reverse genetics approach. Here we aimed at applying the same strategy in grapevine in order to deeply investigate the metabolic changes induced by the overexpression of the mutated or non-mutated form of VvDXS1. Embryogenic callus of a microvine genotype was used for Agrobacterium tumefaciens mediated gene transfer. The molecular characterization of transgenic plants showed that the line with a single T-DNA integration copy had the highest VvDXS1 expression. Besides, transgenic and WT in vitro plants were evaluated for the emission of volatile organic compounds through proton-transfer-reaction mass spectrometry.
Dalla Costa, L., Emanuelli, F., Trenti, M., Lorenzi, S., Cappellin, L., Biasioli, F., Malnoy, M. and Grando, M.S. (2017). Metabolic engineering of volatile isoprenoids in grapevine. Acta Hortic. 1172, 91-94
Vitis vinifera, Muscat aroma, monoterpenes, VvDXS1, gene transfer