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

Anthocyanin biosynthesis occurred in the half-cut grape berry (Vitis labrus cana Bailey, cv. Olympia) cultured in vitro under a continuous irradiance o f 68 mu mol m(-2) s(-1) white light. The use of 1 g l(-1) abscisic acid (AB A) as a culture solution induced 2.5 times higher pigmentation than control (H2O) after 5-day culture. Rhamnose (10%) also accelerated pigmentation si gnificantly, 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 flavanon e isomerase (CHFI, E.C. 5.5.1.6) increased. Thus, ABA, some kinds of sugars , and anthocyanin biosynthetic enzymes in the skin are predominant determin ants, respectively, for berry coloration. (C) 2001 Elsevier Science B.V. Al l fights reserved.