一个小麦csAtPR5-类似基因的克隆、鉴定和表达分析

 小麦(Triticum aestivumL.)品系‘兰考90(6)’在2AL染色体臂上携带1个隐性抗白粉病基因,暂命名为PmLK906。以‘中国春’/‘兰考90(6)21-12’杂交F₃代纯合株系构建的抗、感cDNA池为探针进行小麦基因芯片杂交,结果表明与粗山羊草(Aegilops tauschii)csAtPR5类似的基因在抗病池中的表达量比感病池中约高2^4.2倍。随后,从‘兰考90(6)21-12’中成功克隆了一个2 125 bp的全长csAtPR5-类似基因cDNA序列,暂命名为TaAetPR5(GenBank登录号:EU082094)。TaAet-PR5与csAtPR5的cDNA序列有93%的相同。TaAetPR5编码1个由657个氨基酸组成的多肽,与csAtPR5有88%的相同。蛋白推导分析表明TaAetPR5的分子量为74.5 kDa,pI 6.82,可能是一个可溶性的球蛋白,存在于细胞核中的可能性是95%。接种小麦白粉病菌(Blumeria graminisf.sp.tritici)后12至72 h,‘兰考90(6)21-12’幼苗叶片中的TaAetPR5基因转录水平不断提高。感白粉病的‘中国春’中没有检测到TaAetPR5基因。

Cloning, Characterization and Expression of a csAtPR5-Like Gene in Wheat

Wheat (Triticum aestivum L.) line ' Lankao 90 (6) ' carded a recessive powdery mildew resistance gene which was temporarily named PmLK906 and located on chromosome 2AL. Wheat gene chip hybridization was made by using powdery mildew resistant and susceptible cDNA bulks as probes assembled with homozygous F3 lines derived from a cross of ' Chinese Spring'/' Lankao 90 (6) 21-12'. The results indicated that a gene similar to csAtPR5 of Aegilops tauschii was expressed about 2~4.2 times higher in the resistant bulk than in the susceptible bulk. Subsequently, a new 2 125 bp full-length cDNA clone similar to csAtPR5, temporarily named TaAetPR5 (GenBank accession number: EU082094), was isolated from ' Lankao 90(6)2112'. The cDNA sequences of TaAetPR5 and csAtPR5 shared 93% identity. TaAetPR5 encoded a peptide consisted of 657 amino acids, and was 88% identity to that of csAtPR5. Prediction analysis showed protein TaAetPR5 was 74.5 kDa, and that its pI was 6.82. TaAetPR5 was probably a soluble globular protein and was in nucleus with 95% possibility. The transcribing of TaAetPR5 in ' Lankao 90(6)21-12' was enhanced from 12 to 72 hours after inoculation with Blumeria graminis f. sp. tritici. TaAetPR5 couldn' t be detected in powdery mildew susceptible cultivar 'Chinese Spring'