SCAN:Impact of the irrigation regime applied to Aragonez (Syn. Tempranillo) grapevines on grape berry flavonoids and ABA biosynthesis and accumulation

SCAN Seminar

Title: Impact of the irrigation regime applied to Aragonez (Syn. Tempranillo) grapevines on grape berry flavonoids and ABA biosynthesis and accumulation.

Speaker: Olfa Zarrouk

From: Post-doctoral Fellow at
Molecular Ecophysiology Lab

Abstract:

To understand the effect of different irrigation systems on flavonoid and abscisic acid (ABA) metabolism and accumulation in skin and seeds along grape berry ripening, field grown Aragonez (Syn. Tempranillo) grapevines (Vitis vinifera L.) were subjected to three irrigation regimes (conventional sustained Deficit Irrigation (DI), Regulated Deficit Irrigation (RDI) and Non-Irrigated (NI)) during two successive seasons (2007-2008). An integrative study was performed in grape berry tissues at four phenological stages of grape berry (pea size, véraison, mid-ripening and full maturation). Results showed that there were significant effects of the irrigation regime on the concentrations of ABA and ABA-GE and on the transcript profiles involved in ABA metabolism suggesting an effect of irrigation on the grape berry ripening process. It was observed that the flavonoid pathway was also modulated by the irrigation regime, in which anthocyanin was the most affected compound in grape skin. In grape seeds, proanthocyanidin contents were generally higher in DI and RDI vines that NI ones. In addition, transcriptional profile of their structural genes was modulated by the irrigation regime although expressions did not match with the content. Our results also showed that climatic conditions, namely temperature, play an important role in the ripening process of grape berries. Principal component analysis followed by a between group analysis (PCA-BGA) showed a clear separation already at early stages of grape berry development between the three treatments in both years. These results showed that PCA-BGA is a valuable tool to determine the irrigation effects in field experiments where several factors either than irrigation could be responsible for differences in the accumulation of secondary compounds and hormones.