Endogenous levels of abscisic acid in various organs of Vitis vinifera L. (cv. Cabernet Sauvignon) between flower buds separated and grape closed stages
Abstract
Free abscisic acid (ABA) and bound abscisic acid (ABA-GE: ABA glucose ester) contents and growth were investigated in leaves, internodes, flowers buds, flowers and berries of Vitis vinifera L. cv. Cabernet Sauvignon between flower buds separated and grape closed stages. The ABA levels in leaves and in internodes decrease when the growth was hight and increases when the growth become smaller or stopped. What is more, ABA was accumulated hightly in the flowers (at 50% of flowering) and then appears to be a good marker of flowering. ABA contents decreased at berry setting and till grape closed stage. In leaves, internodes, flowers buds and flowers, ABAGE and ABA show an inverse development and then suggests an interconversion phenomenon between theses two forms. Two most importants points were discuted in this paper: 1) The role of ABA in the controle of growth and development of the organs studied and (2) The translocation of abscisic acid between the organs studied and the role of ABA-GE in this transport.