Gene expression elicitation of enzymes involved in trans-resveratrol and anthocyanins biosynthesis on Bonarda berries.

M. I. DE ROSAS, M. F. DURAN, L. DEIS, L. E. MARTÍNEZ

Simposio; Ninth International Symposium on Grapevine Physiology and Biotechnology; 2013

Gene expression elicitation of enzymes involved in trans-resveratrol and anthocyanins biosynthesis on Bonarda berries. M. I. de Rosas1, M. F. Duran1, L. Deis1, L. E. Martínez1 1Cat. Fisiología Vegetal, FCA, UNCuyo. IBAM-CONICET. Mendoza, Argentina. Anthocyanins (ANT) and trans-resveratrol (TR) are phenolic compounds present in grapes that are very important for wine industry and contribute to the nutraceutical properties of this beverage. The aim of this work was to elicitate the production of these berry polyphenols by using salicylic acid (SA) and UVC light irradiation. Bonarda bunches were sprayed 2 times with SA 3 mM, the first one was done at veraison and the second one 15 days later. After harvest, berries were exposed to UVC light, for 120 s, 240W. Berries skins polyphenols were extracted, and ANT and TR were analyzed by HPLC. Using quantitative real-time RT-PCR, the expression of phenylalanine ammonia-lyase (PAL), flavonoid 3’5’ hydroxylase (F3’5’H), flavonoid 3’ hydroxylase (F3’H) and stilbene synthase (STS) genes involved in ANT and TR synthesis were characterized. ANT profile changed with SA and UVC light revealing a decrease of the tri-substituted ANT, delfinidin-3-glucoside, petunidin-3-glucoside and malvidin-3-glucoside compared with the control berries. The tri-substituted/bi-substituted ANT ratio was also significantly lower. The profile change implicates a switch on the berries tonality towards reddish colors given by the bi-substituted ANT, cyaniding -3-glucoside and peonidin-3-glucoside. High correlation was detected with the F3’5’H / F 3’H gene expression ratio which was lower with SA and UVC light treatment. Despite the total ANT content decrease the expression of PAL genes in the treated berries was increased, suggesting the precursors were over produced, but re-directed to other polyphenols pathways such as TR. In fact, the TR content was significant duplicated on the treated berries than the control ones. Verifying this, the STS gene expression increased on the treated berries. These results indicate that it is possible to increase the content of TR and change the ANT profile in Bonarda berries with SA and UVC light. They also contribute to the understanding of the polyphenols biosynthetic pathway, suggesting the possibility of manipulate its profile, according to an expected result.