Coordinated regulation of vegetative and reproductive branching in rice

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 112; no. 50; pp. 15504 - 15509
• Main Authors: Wang, Lei, 王磊, Sun, Shengyuan, Jin, Jiye, Fu, Debao, Yang, Xuefei, Weng, Xiaoyu, Xu, Caiguo, Li, Xianghua, Xiao, Jinghua, Zhang, Qifa, 张启发
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences 15.12.2015; National Acad Sciences
• Subjects: Agricultural production; Amino Acid Sequence; Biological Sciences; Cereals; Epistasis, Genetic; Gene Expression Regulation, Developmental; Gene Expression Regulation, Plant; Genes, Plant; Genetics; Grain; Grasses; Meristem - genetics; MicroRNAs - genetics; MicroRNAs - metabolism; Molecular Sequence Data; Oryza - anatomy & histology; Oryza - growth & development; Oryza - ultrastructure; Plant Proteins - chemistry; Plant Proteins - metabolism; Plant Stems - anatomy & histology; Plant Stems - growth & development; Plant Stems - ultrastructure; Protein Binding; Reproduction; Rice; RNA-protein interactions; Oryza sativa; microRNA; spikelet; lateral branch; panicle
• DOI: 10.1073/pnas.1521949112
• ISSN: 0027-8424; 1091-6490

Grasses produce tiller and panicle branching at vegetative and reproductive stages; the branching patterns largely define the diversity of grasses and constitute a major determinant for grain yield of many cereals. Here we show that a spatiotemporally coordinated gene network consisting of theMicroRNA 156(miR156/)miR529/SQUAMOSA PROMOTER BINDING PROTEIN LIKE (SPL)andmiR172/APETALA2(AP2) pathways regulates tiller and panicle branching in rice. SPL genes negatively control tillering, but positively regulate inflorescence meristem and spikelet transition. Underproduction or overproduction ofSPLsreduces panicle branching, but by distinct mechanisms:miR156andmiR529fine-tune theSPLlevels for optimal panicle size.miR172regulates spikelet transition by targeting AP2-like genes, which does not affect tillering, and the AP2-like proteins play the roles by interacting with TOPLESS-related proteins (TPRs).SPLs modulate panicle branching by directly regulating themiR172/AP2andPANICLE PHYTOMER2(PAP2)/Rice TFL1/CEN homolog 1(RCN1) pathways and also by integrating other regulators, most of which are not involved in tillering regulation. These findings may also have significant implications for understanding branching regulation of other grasses and for application in rice genetic improvement.