GraSis critical for chloroplast development and affects yield in rice

Leaf color has been considered an important agronomic trait in rice (Oryza sativaL.) for a long time. The changes in leaf color affect the yield of rice. In this study, a green-revertible albino(graS) mutant was isolated from a 60Co-gamma-irradiated mutant pool of indicacultivar Guangzhan 63-4S. The fine mapping indicated that graSmutant was mapped to chromosome 1, and was located in a confined region between markers ab134 and InDel 8 with genetic distances of 0.11 and 0.06 cM, respectively. Based on the annotation results, four open reading frames (ORFs) were predicted in this region. Sequence analysis revealed that LOC_Os01g55974had a 2-bp nucleotide insertion (AA) in the coding region that led to premature termination at the 324th base. Sequence analysis and expression analysis of related genes indicated that LOC_Os01g55974is the candidate gene of GraS.We studied the genome and protein sequences of LOC_Os01g55974, and the data showed that GraScontains a deoxycytidine deaminase domain, which was expressed ubiquitously in all tissues. Further investigation indicated that GraSplays an essential role in the regulation of chloroplast biosynthesis, photosynthetic capacity and yield. Moreover, leaf color mutant can be used as an effective marker for the purity of breeding and hybridization.