Abstract
We have isolated, so far, 10 rice bri1 mutants, including d61-1 and d61-2 which were already reported. Accompanying with the phenotype severeness, the length of leaf sheath, the number of the crown roots and lateral roots of seminal root were decreased. We also analyzed the bri1 null mutant, d61-4. The amount of castasterone (CS), an active brassinosteroid (BR), in shoot of d61-4 was approximately 30-fold of the wild-type plant, while CS in root was about the same level. The expression of OsDWARF gene, which encodes C6 oxidase was increased in shoot than in root. As rice BRI1 homologue genes, BRI2 and BRI3 were expressed in root, defect in BRI1 defect may be complemented partly by these genes in this mutant. In d61-4, abnormal embryo development after 5DAP was also observed.
This work was in part supported by PROBRAIN.
