Bf16 Acts as a Key Regulator of Rice Plant Architecture and Panicle Development through Affecting Auxin Biosynthesis Pathway

Rice panicle development largely contributes to its grain yield. Priviously, we indentified Bf16 which encoded a CCAAT-box binding factor protein and caused extremely late heading under both short day and long day condition in rice. Besides, overexpression of Bf16 caused sterile and seed development defect and generated erect dark green leaves and short Culm, as well as abnormal rice panicle. The floret of Bf16 over expressed plants could either show a LAX-Like panicle phenotype or convert to rice seedlings directly without pollination. These seedlings could generate their own root in a wet condition, such as pure water, wet sand, cultural medium, Hydroponic liquid and mud from the natural field. It is very interesting to see that the adult plants from the seedlings show normal panicle architecture in the dry summer condition but the floret-to- seedling phenotype in winter with high humidity. In addition, after 3 generations' planting of the seeding-birthed plants, we found that the T4 plants yielded many seeds, while we could not get any seed before. Further results showed that Bf16 functions through action on Auxin biosynthesis.