BRASSINOSTEROID UPREGULATED1 LIKE1 Induces the Expression of a Gene Encoding a Small Leucine-Rich-Repeat Protein to Positively Regulate Lamina Inclination and Grain Size in Rice.

() positively affects lamina inclination and grain size. knock-out () plants as well as transgenic rice with reduced level of expression produce erect leaves and small grains. Here, we identified a putative downstream gene of () encoding a small protein with short leucine-rich-repeats by cDNA microarray analyses in the lamina joint and panicles of wild-type and plants. Transgenic rice plants with increased expression exhibit increased leaf angle and grain size, which is similar to an activation tagging line whereas double stranded RNA interference (dsRNAi) lines for knock-down generate erect leaves with smaller grains. Moreover, transgenic rice expressing under the control of promoter also shows enlarged leaf bending and grain size phenotypes. Two genes, () and were identified as being upregulated transcriptional activators in the lamina joint of p: plants and induced expression of the two genes driven by promoter caused increased lamina inclination and grain size in rice. Thus, our work demonstrates that a series of genes showing expression cascades are involved in the promotion of cell elongation in lamina joints and functionally cause increased lamina inclination.