TcLr35小麦β(1,3;1,4)葡聚糖苷酶基因cDNA全长的克隆及分析

Cloning and Characterization of β(1,3;1,4) Beta Glucanase Gene from TcLr35 Wheat

根据已发表的植物β(1,3;1,4)葡聚糖苷酶基因设计引物,利用RT-PCR和RACE技术,从被小麦叶锈菌诱导的小麦抗叶锈病基因近等基因系材料TcLr35中获得一个β(1,3;1,4)葡聚糖苷酶基因cDNA全长,命名为PR34,该基因全长序列为1416bp,具有一个编码335个氨基酸的开放阅读框(ORF),其起始密码子ATG位于13bp处,终止密码子TAG位于1015bp处,3'末端有20bp的poly(A)尾,379bp的3'非翻译区。与GenBank中小麦、大麦等多个葡聚糖苷酶基因具有较高同源性;对其推断的氨基酸序列进行分析,含有Glyco_hydro_17保守结构域,为葡聚糖苷酶基因蛋白结构域。Southern杂交显示,该基因在TcLr35小麦基因组中为低拷贝。

One pair of primer was designed based on the β（1,3; 1,4） beta glucanase,a full length wheat β（1,3; 1,4） beta glucanase gene was obtained by RT-PCR and RACE from the RNA of TcLr35 carrying the Lr35 gene conferring resistance against wheat leaf rust induced by the Puccinia triticina named PR34,which was 1 416 bp in length, and included one complete open reading frame encoding 335 amino acids,a 379 bp 3＇ untranslated region（3＇ UTR） and 29 bp poly（A） tails. The initiation codon and stop codon were found in 13 bp locus and 1 015 bp locus respectively. The deduced amino acid sequence showed close homology to beta glucanase proteins which have been isolated from wheat, barley,and many other plants. The deduced amino acids contained Glyco_hydro_17 conserved domains which was related to beta glucanase. Southern blot indicated that the TcLr35 genome contained low copies of PR34 gene.