Florigen in rice: complex gene network for florigen transcription, florigen activation complex, and multiple functions

Regulation of flowering time directly influences successful rice grain production; thus, the long history of domestication and breeding has improved the genetic network of flowering. Recent advances using molecular genomic approaches have revealed the targets of these modifications and the underlying molecular mechanism for flowering. These efforts contributed to identifying the molecular nature of the systemic floral signal `florigen' and have shown how florigen functions, how florigen expression is controlled, and how regulatory pathways are diversified. In this review, we summarize the advances in our understanding of the detailed molecular and genetic mechanisms that allow rice plants to produce flowers at the proper time to ensure grain production.