Effects of methyl jasmonate on the monoterpenes of Muscat Hamburg grapes and wine

BACKGROUND The importance of monoterpenes in grape and wine aroma has compelled researchers to focus on developing methods to increase their abundance. Recent research has revealed that exogenous elicitors can increase the contents of these compounds. This study determined the effects of methyl jasmonate (MeJA) preharvest treatments on the monoterpene profiles of Muscat Hamburg grapes and wine. RESULTS A total of 27 monoterpenes were identified for Muscat Hamburg grapes and wine. The contents of most of the monoterpenes (free and glycosylated forms) in the grapes and wine increased in response to MeJA. An analysis of the expression of the genes in the terpenoid biosynthesis pathway indicated that the related biosynthetic pathways were activated by MeJA. The transcript levels of some genes were consistent with monoterpene production, including VviCSLinNer, VviGwbOciF, VviPNRLin, VviGT14 and VviUGT85A1L1. The developmental expression patterns of the VviPP2B1 and VviMYB24 transcription factor genes were positively correlated with monoterpene accumulation in ripening grapes. CONCLUSIONS Our results suggest that MeJA may be useful for improving the aroma quality of grapes and wines.

Automated summary

This study found that preharvest treatments with methyl jasmonate (MeJA) can increase the levels of monoterpenes in Muscat Hamburg grapes and wine. The expression of genes related to monoterpene production was positively correlated with the accumulation of monoterpenes in grapes.