GW10, a Member of P450 Subfamily Regulates Grain Size and Grain Number in Rice

Abstract

Grain size and grain number play extremely important roles in rice grain yield. Here, we identify GW10 , which encodes a P450 subfamily protein and controlls grain size and grain number by using Lemont ( tropical japonica ) as donor parent and HJX74 ( indica ) as recipient parent. The GW10 locus was mapped into a 20.1 kb region on the long arm of Chromosome 10. Lower expression of the gw10 in panicle is contributed to the shorter and narrower rice grain, and the increased number of grains per panicle. Furthermore, the higher expression levels of some of the brassinosteroid (BR) biosynthesis and response genes are associated with the NIL- GW10 , which strongly suggests that the GW10 is a key node in the brassinosteroid-mediated regulation of rice grain shape and grain number.