小麦及其相关物种rbcL基因序列的比较研究(英文)

Comparison on sequences of rbcL gene between wheat and related taxa

用4个抗白粉病小麦品系构建了一个混合cDNA文库,从该文库中分离到一个新的小麦rbcL基因全长cDNA克隆.至此,已经有3个不同的小麦rbcL基因序列被报道,新rbcL基因cDNA与以前的2个序列分别有1个和3个碱基的差异.新的cDNA长1519bp 基因库查询号:AY328025 .同源性比较发现,新的小麦rbcL基因的cDNA序列与以前报告的小麦rbcL基因的cDNA序列 gi:344052 有一个碱基的差异,从而导致所编码的多肽在144位由Tyr变为Cys.进一步比较分析了在相关物种中rbcL基因的cDNA序列,结果显示,rbcL基因的编码区在不同属的物种间高度保守,并从分子水平表明小麦与大麦、新麦草、赖草、披碱草属等的亲源关系比与水稻、玉米等的近.

A new wheat rbcL gene cDNA was isolated from a cDNA library constructed by mix mRNA from 4 powdery mildew resistant wheat lines.At present,there are 3 different wheat rbcL cDNA sequences reported.Blast analysis showed that there are only 1 and 3 nucleotide base pairs mutation respectively compared with another 2 previous sequences.The new rbcL cDNA is 1 519 bp long (GenBank accession number:AY328025).BLAST showed that the new rbcL gene cDNA had one base pair nucleotide mutation compared with previous wheat rbcL cDNA gi:344052,so that there is an amino acid substitution from tyrosine (Tyr) to cysteine (Cys) at position 144 in the new putative polypeptide.Comparative analysis of some rbcL gene cDNA sequences between wheat and other species were also carried out,the result suggested that the rbcL gene was highly conserved in examined species,common wheat is more closer related with Hordeum,Psathyrostachys,Leymus,Elymus than with Oryza and Zea .