Genes of the RAV family control heading date and carpel development in rice (Plant Physiol)

Seed-bearing annual plants essentially get one shot at getting their reproductive timing right; too early and there won’t be enough stored nutrients to produce healthy seeds, and too late and the seeds might not mature fully before bad weather or rot sets in. Previously, the RAV (RELATED TO ABI3 AND VP1) family of transcription factors was shown to have a role in delaying flowering time in Arabidopsis, specifically by repressing expression of the FT gene and genes encoding gibberellin biosynthesis, as well as other functions. Here, Osnato et al. examined the RAV genes in rice. One, OsRAV9 (also known as OsTEM1), was shown to repress flowering time in functional studies of both rice and Arabidopsis, although in rice the effect appears to be indirect, acting through MADS-box genes, rather than direct. Other OsRAV genes were found to contribute to carpel development, a function that is distinct from the corresponding Arabidopsis genes. In short, the rice RAV genes have some functional overlap with those from Arabidopsis and some distinct functions in development. (Summary by Mary Williams @PlantTeaching) Plant Physiol. 10.1104/pp.20.00562