草莓八氢番茄红素脱氢酶基因pds的克隆及特征分析

Cloning and Characterization of pds Gene in Fragaria×ananassa

采用RT-PCR和RACE技术从草莓果实中克隆到草莓类胡萝卜素合成途径中关键基因pds,该cDNA全长2043bp,具有一个1704bp的完整开放阅读框(ORF),编码568个氨基酸。序列分析表明,pds编码的氨基酸序列与其它植物的PDS蛋白有很高的相似性。系统进化树分析显示,草莓PDS与杏的PDS蛋白亲缘关系比较近。原核表达结果表明pds基因在大肠杆菌中获得高效表达。利用半定量RT-PCR技术进行组织表达模式分析发现,pds基因在草莓的花、叶片和果实中均有表达,表达量为红果>粉红果>白果>花>青果>叶。

The pds cDNA sequence was cloned from strawberry fruit using RT-PCR and RACE techniques.The cDNA sequence consists of 2 043 bp with an intact open reading frame of 1 704 bp,encoding a polypeptide of 568 amino acids.Homology analysis showed that the deduced PDS protein was highly homologous to other PDS proteins from different species.Phylogenetic analysis also indicated that PDS was close to PDS of apricot.Prokaryotic expression showed Recombinant pds was efficiently expressed in Escherichia coli BL21.The semi-quantitative RT-PCR analysis revealed that pds can be expressed in different strawberry tissues,and the expression level was differed in these tissues,the highest expression level was detected in fruits at the red ripening stage,while moderate expression levels were found in fruits at the pink ripening stage,white fruits,flowers and green fruits,the lowest level was present in leaves.