甘薯AGPase大小亚基基因的克隆与序列分析

Molecular cloning and characterization of large and small subunits of ADP-glucose Pyrophosphorylase from sweetpotato

利用RT-PCR方法从甘薯品种广紫薯1号中克隆出淀粉合成关键酶-腺苷二磷酸葡萄糖焦磷酸化酶(ADP-Glucose Pyrophosphorylase,AGPase)大小亚基基因的cDNA序列,大亚基命名为ibAGPL1,小亚基分别命名为ibAGPSI和ibAGPsII。序列分析表明,该cDNA序列均包含了完整的开放阅读框。系统进化树分析表明,所克隆基因编码的氨基酸序列与其他植物来源的AGPase大小亚基氨基酸序列有较高的同源性,尤其是与双子叶植物来源的大小亚基基因亲缘关系较近。这3个基因的克隆期望为下一步甘薯转基因育种研究提供候选基因。

ADP-glucose pyrophosphorylase(AGPase) is one of the major enzymes involved in starch biosynthesis in higher plants.The molecular cloning of 3 cDNAs encoding one large and two small subunits isoforms(ibAGPL1,ibAGPSI and ibAGPSII) of the sweetpotato enzyme were studied.Sequence analysis showed that the three polypeptides are more homologous to previously identified large and small subunit polypeptides from potato and other dicotyledonous species than to large and small subunit isoforms from gramineous species.These genes will be used as candidate genes for improving starch synthesis in transgenic sweetpotato.