A. Ilan et al., GIBBERELLIC-ACID DECREASES ANTHOCYANIN ACCUMULATION IN WILD CARROT CELL-SUSPENSION CULTURES BUT DOES NOT ALTER 3'-NUCLEOTIDASE ACTIVITY, Physiologia Plantarum, 92(1), 1994, pp. 47-52
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).