Carbon transportation from source to sink in Vitis vinifera L. is increased by Abscisic acid through enhancement of vascular tissues and sugar transporters

GERMÁN MURCIA; MARIELA PONTIN; HERMINDA REINOSO; RITA BARALDI; GIANPAOLO BERTAZZA; SEBASTIÁN GOMEZ-TALQUENCA; RUBÉN BOTTINI; PATRICIA PICCOLI

Mar del Plata

Congreso; XV Congreso Latinoamericano, XXX Reunión Argentina de Fisiología Vegetal.; 2014

Grape quality for winemaking is highly dependent on sugar accumulation in berries. ABA and Gibberellins (GAs) and have been reported to control sugar allocation in economically important organs. This work examined the content of sugars and organic acids of berries related to vascular bundles anatomy and to gene expression of sugar transporters in field pot-grown grapevines (Vitis vinifera cv Malbec) at full veraison sprayed with ABA, GA3 and uniconazole (inhibitor of GA biosynthesis and of ABA degradation). ABA and GA3 promoted xylem and phloem differentiation in stem, leaf, and, berry pedicel tissues. Higher glucose and fructose concentrations in berries of ABA-treated plants were correlated with an enhancement of Vitis vinifera HEXOSE TRANSPORTER2 (VvHT2), Vitis vinifera TONOPLASTIC MONOSACCHARIDE TRANSPORTER1 (VvTMT1) and Vitis vinifera VACUOLAR INVERTASE1 (VvGIN1) gene expression and with an increase of the berry pedicel phloem area. GA3 increased flux of photoassimilates delivered to the stem so augmenting xylem growth. In conclusion, ABA increased carbon transport from the source to sink in Vitis vinifera by improving phloem growth, gene expression of sugar transporters and plant water status.