摘要
Identification of regulatory genes from chalky/floury endosperm mutants is an important approach to understand the mechanism of starch biosynthesis to accelerate rice grain quality improvement.A mutant GM645,identified from 60Coγ-irradiation of an indica rice Guanglu’ai 4(GLA4),exhibited white-core endosperm and altered starch physicochemical properties.However,the causal gene responsible for the white-core endosperm in GM645 has not been identified.Here,we developed a recombined inbred line(RIL,F7)population derived from a cross between GM645 and a japonica rice Tainong 67(TN67)with translucent endosperm.Bulkedsegregant analysis combined with next generation sequencing revealed five single nucleotide polymorphisms(SNPs)in four candidate genes that were highly associated with the white-core endosperm.Among them,one base pair deletion in Os04g0645100 resulted in a frame shift mutation after the 983th amino acid(aa),and a premature stop codon occurred after the other 11 aa.Moreover,functional annotation revealed that Os04g0645100 was previously characterized as the FLOURY ENDOSPERM2(FLO2)gene.Full-length coding sequence from Os04g0645100 driven by the maize ubiquitin promoter was transformed into GM645,and seeds from these transgenic plants expressing Os04g0645100 were largely rescued to translucent,indicating that Os04g0645100 was responsible for the whitecore endosperm in GM645.
基金
supported by the Zhejiang Provincial Natural Science Foundation(Grant No.LZ21C130003)
National Natural Science Foundation of China(Grant No.31961143016).
