白菜型油菜八氢番茄红素脱氢酶基因PDS3的克隆与序列分析

Cloning and analyzing BrPDS3 gene of phytoene desaturase in Brassica rapa L.

利用电子克隆技术,从数据库中找到与拟南芥高度同源的油菜EST序列,继而通过RT-PCR和RACE等方法,成功克隆了白菜型油菜八氢番茄红素脱氢酶(类胡萝卜素合成途径中的一个关键限速酶)基因PDS3的cDNA,命名为BrPDS3(GenBank登记号GQ200741)。cDNA序列全长1 940bp,其中包含114bp的5'前导序列和134bp的3'不翻译序列,编码区长度为1 692bp,编码63kD的蛋白。序列分析表明,BrPDS3蛋白与其他植物的PDS蛋白具有较高相似性;在系统进化树中,BrPDS3与甘蓝亲缘关系最近。根据全长cDNA序列设计引物,从白菜型油菜青油13号DNA中克隆得到BrPDS3基因的全长DNA,长度为3 911bp,ORF(开放阅读框)1 692bp,含有15个外显子和14个内含子。

Using in silico cloning method,a phytoene desaturase gene was obtained from Brassica rapa EST database.It was named as BrPDS3（accession number GQ200741）,encoding a key enzyme in carotene biosythesis pathway.By RT-PCR and RACE methods,BrPDS3 cDNA putative full length was assembled 1 940bp long,including 114bp 5′ UTR（untranslated region）,134bp 3′ UTR and 1 692bp ORF（open reading frame） coding a 63kD protein.BrPDS3 protein was highly homologous to other PDS3 proteins from different species.Phylogenetic analysis indicated its close relationship to B.oleracea.BrPDS3 DNA sequence was 3 911bp including 15 exons,14 introns.