A study on the meristem fate regulation by TAW1 in rice panicle development

概要

Rice (Oryza sativa) is one of the most widely consumed staple foods in the world, making it one of the most important crops. Panicle formation is an important process in rice development which determines grain yield. In the rice development process, rice will grow starting from the vegetative phase until the transition to the reproductive phase, which changes the fate of the shoot apical meristem (SAM) to the inflorescence meristem (IM). In rice, the main axis of the inflorescence is known as the rachis. The IM forms main rachis, primary branch meristem (PBM), secondary branch meristem (SBM), and spikelet meristem (SM). PBM are the lateral branch meristems that attached directly to the main rachis. While, the lateral branch meristems that are attached to the PBM are termed SBM. During the rice IM development, the early IM acquires an indeterminate branch meristem (BM) identity and continuously produces PBM and SBM, until, eventually, the determination of its fate into the SM. Several genes involved in the control of rice panicle development have been reported. TAWAWA1 (TAW1), encodes an Arabidopsis LSH1 and Oryza G1 (ALOG) transcription factor, is a regulator of rice panicle architecture through the suppression of BM phase transition to SM identity and extending IM activity. The taw1-D2, an overexpression TAW1 mutant, showed an increase of secondary branches. However, the mechanism(s), in which TAW1 regulates the meristem fate, is still unknown. Understanding the molecular basis of meristem fate determination during rice panicle development will greatly aid the development of high yield rice variety. Thus, the purpose of this study is to gain a better understanding of the molecular basis of meristem phase change by TAW1.