Endogenous gibberellins in immature seeds and flowering ears of rice.

Abstract

Endogenous gibberellins (GAs) in immature seeds and flowering ears of rice ( Oryza sativa L.) were investigated, and six 13-OH GAs (GA1, GA19, GA20, GA29, GA44 and GA53) and five 13-H GAs (GA4, GA9, GA24, GA34 and GA51) were identified. The existence of these GAs suggests that two major GA biosynthetic pathways exist in rice, one being that of the 13-OH GA series and the other, the 13-H GA series. The major GA was GA4 in ears, and GA34 in immature seeds. The occurrence of 13-H GAs in reproductive organs suggests that 13-H GAs may play important roles in the regulation of reproductive growth.