Gibberellins Regulate Expression of Cyclins to Control Leaf Width in Rice

Abstract

Leaves are the nutritive organs of rice. Leaf shape influences rice photosynthesis, subsequently impacting yield. Gibberellins, GAs, are important hormones, but the way in which GAs regulate leaf width is largely unknown. This study focuses on the d18 mutant with broader leaves due to defective GA biosynthesis. Statistical analysis indicates broader leaves in the d18 mutant compared to the wild-type group. An examination of leaf cell morphology shows a higher count of secondary vascular bundles in d18 than in the wild-type group. RNA-seq analysis demonstrates significantly higher expression of CYCB (CYCLIN B) and H4 (HISTONE H4) in d18 compared to wild type. In summary, the leaf width of d18 may due to a higher activity of cell division at leaf margin.