Research Advance in Molecule Regulation Mechanism of Leaf Morphogenesis in Rice (Oryza sativa L.)

Rice leaf morphosis is one of important components in the design of ideal plant architecture, and is the main focus in high-yield breeding of rice. The paper expounds the advance in the molecular genetics research of rice leaf morphosis (including leaf rolling, leaf angle, leaf drooping, and leaf width) by analyzing the leaf shape regulating genes that have been cloned. Comprehensive analysis reveals that the leaf rolling is controlled by related genes that regulate the development of leaf along the adaxial-abaxial axis, the development of bulliform cells, osmotic pressure or turgidity in bulliform cells, the formation of sclerenchymatous cells and the development of cuticle. Leaf inclination, which affects the plant space extension posture, is regulated by the development of phyllula which is controlled by genes conferring the biosynthesis or signaling of phytohormone brassinosteroids (BRs). The only cloned drooping leaf gene controls the leaf shape by influencing midrib formation. Narrow leaf genes regulate the leaf width through controlling the synthesis of auxin and its polar transport, and the development and distribution of vascular tissues. However, the study on the relationship between regulation roles of these cloned leaf shape genes. is not profound enough to draw an outline of molecular regulation network for rice leaf development and morphosis completely and clearly. Therefore, on the basis of current research findings, it is of great significance to further explore the rice leaf molecular regulation mechanism for establishing related regulation network and shaping ideal rice plant architecture.