苦楝白化叶SGR基因克隆与生物信息学分析OA

In order to investigate the causes of leaf albinism in Melia azedarach,this study used green leaves and albino leaves as research subjects.Through freehand sectioning and microscopic observation of cell color distribution,the contents of chlorophyll and carotenoids were measured.Additionally,the key chlorophyll degradation gene SGR was cloned and subjected to bioinformatics analysis.The results showed that in the albino leaves,green cells were almost undetectable in both the palisade and spongy tissues.The total chlorophyll content in green leaves was 1.66 mg·g-1,significantly higher than that in albino leaves(1.02 mg·g-1).Similarly,the carotenoid content in green leaves was 0.34 mg·g-1,markedly higher than that in albino leaves.Cloning and analysis of the SGR gene in M.azedarach revealed that the full-length CDS of this gene was 345 bp,encoding 115 amino acids.The SGR protein was alkaline,hydrophobic,non-secretory,and non-transmembrane,with its secondary structure predominantly composed of random coils.Subcellular localization prediction indicated its presence in the cytoplasm.Phylogenetic analysis showed that the SGR gene of M.azedarach was most closely related to that of Sarracenia purpurea.Therefore,the reduction in chlorophyll is the key factor leading to leaf albinism in M.azedarach.Further in-depth research on the SGR gene,a critical gene involved in chlorophyll degradation,will contribute to elucidating the molecular mechanisms underlying the albino leaf phenotype in M.azedarach.