Encoding Heat Shock Protein Regulates Leaf Size in Rice.

Leaf size is an important agronomic trait directly affecting yield in rice, and thus understanding the genes determining leaf size is important in breeding. In this study, one () with small leaf size was isolated using ethyl methane sulphonate (EMS) mutagenesis from the Zhenggeng 1925. MutMap by whole genome resequencing of phenotypic bulks revealed that is likely located in the 133 kb region on chromosome 7 using F population from a cross between and wild-type (WT) Zhenggeng 1925. The candidate gene encoding heat shock protein for was functionally validated. Disruption of this gene in mutants significantly reduced the leaf size compared with that of WT in rice. Microscopic examination showed that modulated leaf size via regulating the veins formation and cell size/cell number. Nucleotide diversity analysis indicated that a single nucleotide polymorphism (SNP) variation of C to T in the coding region of may cause small leaves among rice accessions. Therefore, the natural variation of contributing to leaf size might be useful for rice breeding.