Ipomoea trifida（2 X）抗坏血酸过氧化物酶基因的克隆、序列分析和表达分析

摘要

为了从甘薯野生资源中获取抗逆基因，提取 Iponoea trifida 组培苗总 RNA，经反转录获得第一链 cDNA，使用特异引物进行 PCR扩增，获得了 I. trifida抗坏血酸过氧化物酶编码区序列，并进行生物信息学分析以及组织特异性表达研究。经测序表明，所获得的序列长约769 bp，包含753 bp完整的开放阅读框；生物信息学分析结果表明，此序列编码250个氨基酸，蛋白大小约为27.6 kDa，等电点为5.42，有大范围亲水区，推测在细胞质中起到抗氧化作用；进化发育系统分析表明，ItAPX和 IbAPX最为接近；组织特异性表达分析表明，ItAPX 在各组织中均有表达。I. trifida抗坏血酸过氧化物酶基因的克隆为甘薯抗逆育种提供了新的基因资源。%In order to get stress resistance genes from wild resources of sweet potato,total RNA was extracted from tissue culture seedlings of Iponoea trifida,cDNA first-strand was obtained by reverse transcription,a 769 bp sequence was amplified by PCR using specific primers. The I. trifida ascorbate peroxidase enzyme coding region was obtained,bioinformatic analysis and expression pattern analysis were conducted. Sequencing results showed that the sequence contained a complete open reading frame of 753 bp encoding 250 amino acid residues. The putative pro-tein size was approximately 27. 6 kDa,isoelectric point was 5. 42,and there was a wide range of hydrophilic region. It was speculated that the protein played antioxidant role in the cytoplasm. Phylogenetic analysis indicated that IbAPX was most closely genetically related to ItAPX. Tissue-specific expression analysis showed that ItAPX ex-pressed in all organs. Cloning of I. trifida ascorbate peroxidase gene would help sweet potato breeding for stress-tol-erance with new genetic resources.