水稻黄叶转绿突变体818-6-8的目标基因定位与转录组分析OA

[Objective]Leaf is the most important photosynthetic organ in rice.Screening and identification of rice leaf color mutants are beneficial for exploring the molecular regulatory mechanisms of chloroplast development and photosynthesis.[Method]A green-revertible yellow leaf mutant 818-6-8 was obtained from the gene-editing lines of Jingeng 818.Phenotypic identification,genetic analysis,gene mapping,and transcriptome analysis for 818-6-8 were performed.[Results]Compared with the wild type,the mutant showed an obvious yellow-leaf phenotype until the three-leaf stage,accompanied by a significant decrease in chlorophyll content.As it grew,the mutant turned green and gradually became indistinguishable from the wild type at the four-leaf stage.Fewer chloroplasts,abnormal thylakoid morphology and stromal lamellas structure were observed in the mutant.The yellow-leaf trait of 818-6-8 was controlled by a pair of recessive nuclear alleles.The target mutation site was located within a 2.29 Mb interval on chromosome 5,and 20 annotated candidate genes were listed.The expression levels of 2090 genes in the mutant were significantly changed compared to the wild type,of which 1343 genes were up-regulated and 747 genes were down-regulated.Further,the differentially expressed genes were enriched in biological processes such as chloroplast organization and cellular components such as chloroplasts.The expression of genes associated with chlorophyll biosynthesis and chloroplast development of 818-6-8 changed significantly.[Conclusion]These results support the next studies for cloning target genes and analyzing chloroplast-development molecular mechanisms,and provide a germplasm resource for ornamental rice breeding.