荔枝果皮2个POD同源基因的生物信息学分析及酶活测定

Bioinformatics Analysis and Function Forecast of Two POD Genes in Litchi chinensis Pericarp

根据荔枝果皮cDNA文库,克隆到荔枝果皮的2个过氧化物酶基因,分别命名为LiPOD1和LiPOD2。经生物信息学分析表明,LiPOD1的ORF全长为1 062 bp,编码353个氨基酸;LiPOD2的ORF全长为990 bp,编码329个氨基酸。Blast分析表明,LiPOD1所推导的氨基酸序列与橡胶、毛果杨、甘薯具有较高的一致性,分别为87%、84%、81%;LiPOD2所推导的氨基酸序列与棉花、胡麻、紫花苜蓿、拟南芥具有较高的一致性,分别为88%、87%、85%、81%。保守结构域的分析表明,LiPOD1、LiPOD2基因均含有过氧化物酶完整的保守结构域,包括血红结合位点、活性位点、底物结合位点、钙离子结合位点。荔枝果皮褐变指数与过氧化物酶活性在常温贮藏过程中均呈增加的趋势。该研究结果对进一步验证这2个基因在荔枝果皮褐变衰老过程中的功能具有重要的理论意义。

Two POD genes were cloned from the pericarp of Litchi chinensis and named as LiPOD1 and LiPOD2,respectively.Analysis indicated that the full length of LiPOD1 was 1 062 bp with an open reading frame encoding 353 amino acids that shared high identities with the POD from Hevea brasiliensis,Populus trichocarpa,Ipomoea batatas（87%,84% and 81%.The full length of LiPOD2 was 990 bp with an open reading frame encoding 329 amino acids that shared high identities with the POD from Gossypium hirsutum,Sesamum indicum,Medicago sativa,Arabidopsis thaliana（88%,87%,85% and 81%）.Analysis of conserved domains indicated that LiPOD1 and LiPOD2 both had total conserved domains of POD gene and had heme binding site,active site,substrate binding site and calcium binding site.During the process of skin browning within 72 hours both the browning index and POD activity increased.Analysis of structure of LiPOD1 and LiPOD2 speculated that these two genes played important roles in the process of pericarp senescence and browning in postharvest Litchi chinensis.