彩色马铃薯查尔酮合酶基因的克隆及生物信息学分析

Cloning and Bioinformatics Analysis of the Chalcone Synthase Gene from Color Potato (Solanum tuberosum)

为了研究彩色马铃薯块茎中花色苷积累的分子机制,明确查尔酮合成酶(CHS)在花色苷合成途径中作用,本研究以彩色马铃薯品种‘红美’块茎作为实验材料,根据GenBank数据库中已注册马铃薯CHS基因的cDNA序列设计引物,通过RT-PCR方法克隆了一个CHS基因,命名为StCHS1b。StCHS1b基因cDNA序列共1 223 bp,开放阅读框为1 170 bp,编码389个氨基酸。分子质量约为42.48 kD,理论等电点为6.3。生物信息学分析表明,该蛋白为亲水性的稳定蛋白质,而且含有CHS家族序列标签的保守区域GVLFGFGPGLT,无信号肽,不含有跨膜区。Blastn分析表明,StCHS1b基因序列与其他物种的CHS基因序列均具有较高同源性,编码区氨基酸相似性高达99%。进化分析表明,彩色马铃薯StCHS1b与番茄SlCHS、茄子Sm CHS、辣椒CaCHS、烟草NtCHS和黑果枸杞LrCHS聚在同一个分支,都属于茄科,它们的亲缘关系最近,与苹果MdCHS和覆盆子RiCHS亲缘关系较远。

In order to study the molecular mechanism of anthocyanin accumulation, explore the function of chalcone synthase in anthocyanin synthesis process, we used potato variety ’Hongmei’ tuber as the experimental materials. Based on the information of potato in GenBank database, the chalcone synthase gene was cloned from color potato by RT-PCR and named StCHS1b. The cDNA sequence of StCHS1b gene was 1 223 bp and it contained a complete ORF including 1 170 bp which encoded 389 amino acids. Its relative molecular weight was about 42.48 kD, and the isoelectric point was 6.3. Bioinformatic analysis showed that StCHS1b protein was a hydrophilic and stable protein, and it contained the conserved domain GVLFGFGPGLT of CHS family tag. It has no signal peptide and transmembrane structural domain. Blastn analysis revealed that StCHS1b gene sequence has high homology with CHS gene sequence of other species, and the amino acid similarity of coding region is as high as 99% Phylogenetic analysis showed that color potato StCHS1b was clustered in the same branch with tomato Sl CHS, eggplant SmCHS, pepper CaCHS, tobacco NtCHS and black wolfberry LrCHS, which belonged to Solanaceae. They had the closest genetic relationship and were far away from apple MdCHS and raspberry RiCHS.