Effect of methyl jasmonate on the aroma of Sangiovese grapes and wines

- The effects of MeJA on berry aromas and expression of TPS genes were assessed.
- The elicitor led to an increase in the concentration of aroma in berries and wines.
- Monoterpenes were the most influenced by the elicitor application.
- All the TPS genes analyzed were more expressed in samples treated with MeJA.
- MeJA treatment could be a useful tool to improve grapes and wines quality.

Methyl jasmonate (MeJA) was applied in a vineyard on leaves and grape clusters of cv Sangiovese to test its ability to stimulate the production of aromas and identify the main genes involved in the biosynthetic pathways switched on by the elicitor.MeJA application led to a delay in grape technological maturity and a significant increase in the concentration of several berry aroma classes (about twice the total aroma: from around 3 to 6 μg/g of berry). Of these, monoterpenes showed the most significant increase. An analysis of the expression of terpenoid biosynthesis genes confirmed that the MeJA application activated the related biosynthetic pathway. The expression of all the TPS genes analyzedwas higher in samples treated with MeJA. Also the wines produced by microvinification of Sangiovese treated and untreated grapes showed a rise in the aroma concentration as in berries, with an important impact on longevity and sensorial characters of wines.