수수 지베렐린 함량의 일중변화에 미치는 일장효과

The endogenous gibberellin(GA) levels of sorghum grown under different photoperiodic conditions were measured by GC-MS-SIM. The effect of photoperiods on the diurnal GA levels of the 13-hydroxylation pathway was investigated by sampling every 6 h for 1 day. Levels of GA_(12), GA_(53), GA_(19), GA_(20), GA₁ and GA_8 were not constant throughout sampling times but rather rhythmic in productions. Wild-type seedlings grown under short photoperiod contained more GA_(20) and GA₁ than those of long photoperiod. Although plant height of phyB-1 (phytochrome B mutant) was taller than wild-type under all photoperiods tested, GA₁ concentration of wild-type grown under 10 h photoperiod was higher than that of phyB-1 grown under the same photoperiod. These results are compatible with the idea that phytochrome B changed seedling responsiveness to GAs.