IEPA.d187.s446
Gibbestatin B inhibits the GA-induced expression of alpha-amylase expression in cereal seeds [In Process Citation]
IEPA.d187.s447
The expression of alpha-amylase in aleurone layers of barley is known to be induced by gibberellin A3 (GA).
IEPA.d187.s448
In the present study, gibbestatin B (GNB) was isolated from Streptomyces sp. C-39 as an inhibitor of the GA-induced expression of alpha-amylase in barley and rice, with IC50 values of 125 and 70 microM, respectively.
IEPA.d187.s449
GNB suppressed accumulation of GA-induced barley high-pI type B and rice RAmylA alpha-amylase transcripts.
IEPA.d187.s450
These analyses indicate that GNB inhibits the GA-induced expression of alpha-amylase by regulating one of the steps involved in ABA signaling, but not by acting as a weak ABA analog.