The Effect of Pre-Harvest Methyl Jasmonate Treatment on the SelectedVolatile Compounds and Endogenous Hormones Contends in the Pulp ofGrape Berries

Grapevine is one of the most valued and widely cultivated fruit crop worldwide, with their pleasant flavor and valuable health effects. During the consequent ripening at ambient temperature, the volatile compounds of table grape often decreased, to affect their sensory evaluation. The development of new and effective methods to increase the volatile compounds of berries is necessary. Present study was carried out to investigate the pre-harvest methyl jasmonate (MeJA) treatment on the selected volatile compounds and endogenous hormones content from ‘Shine Muscat’ berries pulp. The results indicated that, pre-harvest application of MeJA (0.1 mM or 0.01 mM) on grape berries generally enhanced the production of terpenes, like nerol, linalool, alpha-terpineol; While some C6 compounds were reduced, such as (E)-2-hexenol, hexanol, (Z)-3-hexenol, hexanal and (E)-2-hexenal. The endogenous hormones like IAA (indole acetic acid), ABA (abscisic acid) and JA (jasmonate acid) content were also changed after MeJA treatment. We also observed that MeJA palys a key role in fruit endogenous hormones level and volatile compounds by increasing the expression level of several related genes, such as aroma-related genes Vvter, Vv-syn and hormone-related genes VvOPR3, VvAuI, VvEth, VvNCED1. We hypothesize that, MeJA as an effective elicitor affects the volatile compounds by altering endogenous hormones level in berries pulp of ‘Shine Muscat’.