GA1-deficiency in the UI was caused by IAA-deficiency via the down-regulation of the OsGA3ox2 transcript level. (A) Endogenous IAA levels in the panicles of ZS97A and ZS97B throughout the pollen development process. (I) Stamen and pistil formation stage; (II) Pollen mother cell formation stage; (III) Pollen mother cell meiosis stage; (IV) Uninucleate pollen stage; (V) Binucleate pollen stage; (VI) Trinucleate pollen stage. (B) Endogenous IAA levels in the panicle and in the UI of ZS97A and ZS97B at the heading stage. In (A) and (B), each column represents the mean ±SE of three replicates of independently harvested plant material. FW, fresh weight. (C) Impact of exogenous 50 μM IAA on OsGA3ox2 and OsGA2ox1 transcript levels in the UIs of ZS97A and ZS97B at the early heading stage. For RT-PCR analysis, the UI was harvested 24 h after the first treatment. Actin was used as an internal control.
