Map-based Cloning And Functional Analysis Of A Seedling Albino Lethal Mutant Gene Asl4 In Rice(Oryza Sativa L.)

Leaf color mutants of rice(Oryza sativa L.)are the important materials for functional genomics. Since chlorophyll deficient mutant and photosynthesis are closely related, the research of mutant for this type is significant for clarifying molecular genetic mechanisms of metabolic pathways/chloroplast development. In the study on a novel albino mutant(asl1)based on the characteristics, carry out the work of the gene cloning and expression analysis. The main research results are as follows.1.The asl4 mutant showed the albino phenotype from germination to3-leaf-stage, then died. In comparison with the wild-type parent, “Jiahua 1”, the chlorophyll and carotenoid contents in asl4 mutant was hardly detectable.2. The genetic analysis indicated that the mutant trait was controlled by a single recessive nuclear gene(asl4).In addition, with the help of SSR, new developed In Del markers and F2 and F3 segregating population derived from the cross between theasl4 mutant and the indica rice Guangzhan 63 S,the asl4 was narrowed to 188 kb between the molecular markers ID12974 and ID13739 on chromosome 9.3.Using bioinformatics methods, we determined LOC_Os09g21710 encoding zinc finger proteins for the candidate gene. And sequencing results show that there is a G deletion in LOC_Os09g21710.4. The synthesis of rice chlorophyll in mutant and wild-type analysis shows that the expressions of the genes are influenced by the mutation. The mutation of asl4 gene may cause some expression changes of chlorophyll biosynthesis genes.5. ASL4 analysis of homology among proteins in different species shows that ASL4 of homologous proteins widely exist in many species, evolutionary tree analysis indicates that ASL4 is consistent with the result of traditional plant taxonomy classification.Our research discovered a novel albino lethal mutant gene ASL4 in rice.The results in this study would in favor of the further functions of this gene,and provide a new theoretical basis for the studying on chloroplast development.Key words:Oryza sativa L.; albino; chloroplast;zinc finger protein; map-based...