GIBBERELLIC-ACID DECREASES ANTHOCYANIN ACCUMULATION IN WILD CARROT CELL-SUSPENSION CULTURES BUT DOES NOT ALTER 3'-NUCLEOTIDASE ACTIVITY

Gibberellic acid (GA(3)) applied at different times during the growth of wild carrot (Daucus carota ssp. carota) cell suspension cultures in hibited anthocyanin accumulation. Application of 3 x 10(-6) M GA(3) to cultures on day 0 or day 4 gave, respectively, 10 or 35% of anthocyan in accumulation relative to levels occurring when GA(3) was applied at the end of the growth period. Endogenous GAs were separated by high p ressure liquid chromatography, and identified and quantified by gas ch romatography-selected ion monitoring. Gibberellins GA(1), GA(3) and tr aces of GA(8), GA(19) and GA(20) were identified in carrot cell suspen sion cultures of both high and low anthocyanin-accumulating clones. Th e concentrations of GA(1), GA(3) and GA(8) in the two clones were simi lar and were not significantly different after the application of unic onazole which promoted anthocyanin accumulation. This suggests that th ese endogenous GAs are not the sole factors controlling the accumulati on of anthocyanin in these different clones. Exogenous GA(3) and unico nazole had no effect on 3'-nucleotidase and 5'-nucleotidase activity i n the carrot cell suspension cultures. Thus 3'-nucleotidase does not a ppear to play a role in the inhibition of anthocyanin accumulation by exogenous GA(3).