ABA and sugar effects on anthocyanin formation in grape berry cultured in vitro

Anthocyanin biosynthesis occurred in the half-cut grape berry (Vitis labruscana Bailey, cv. Olympia) cultured in vitro under a continuous irradiance of 68 mu mol m(-2) s(-1) white light. The use of 1 g l(-1) abscisic acid (ABA) as a culture solution induced 2.5 times higher pigmentation than control (H2O) after 5-day culture. Rhamnose (10%) also accelerated pigmentation significantly, but 10% sucrose inhibited it. When ABA was mixed with rhamnose, the promotive effect was pronounced synergistically. In the skin of berry cultured with ABA, soluble sugar content and activity of chalcone flavanone isomerase (CHFI, E.C. 5.5.1.6) increased. Thus, ABA, some kinds of sugars, and anthocyanin biosynthetic enzymes in the skin are predominant determinants, respectively, for berry coloration. (C) 2001 Elsevier Science B.V. All fights reserved.