荆州黑麦NPR1同源基因ScNPR1的克隆与特性分析

Cloning and Characterization of NPR1 Homolog Gene ScNPR1 in Secale Cereale Cv Jingzhouheimai

为了明确荆州黑麦ScNPR1基因的功能,对荆州黑麦NPR1同源基因ScNPR1进行克隆并分析了其表达特性。利用同源序列法和RACE技术从荆州黑麦中克隆得到NPR1同源基因的3 185bp全长cDNA序列,该基因包含了一个编码507个氨基酸(1 524bp)的开放阅读框、终止密码子TGA、5′端1 517bp的非编码区和3′端144bp的非编码区,命名为ScNPR1。利用生物信息学软件对其结构进行分析,ScNPR1编码的氨基酸序列与已知的小麦、水稻NPR1基因编码的氨基酸序列具较高的同源性,分别达到92.4%和90.3%。荧光定量PCR发现,ScNPR1基因在小麦不同器官中均有表达,在叶、茎、根中表达较高;ScNPR1基因在植物抗病相关信号分子水杨酸、茉莉酸和乙烯处理后上调表达,在白粉病菌、纹枯病菌和赤霉病菌的诱导下,ScNPR1基因也上调表达。研究结果表明,ScNPR1基因与水杨酸和乙烯信号转导途径有关,参与寄主对病原菌侵染的防御反应。

NPR1 is a key regulator in plant systemic acquired resistance（SAR）.Scnpr1 gene was isolated by homologous cloning and RACE（rapid amplification of cDNA ends） method from Secale Cereale cv JingzhouHeimai.The full-length cDNA of Scnpr1 gene was 3185 bp,which contained an open reading frame with the length of 1524 bp DNA encoding a 507 amino acids,untranslated region of 1517bp at 5′-end and 144bp at 3′ end..The predicted protein Scnpr1 shares high homology with a reported NPR1 from barley（72%） and a rice NPR1（65%） by using bioinformatics analysis for the structure of ScNPR1.Its expression pattern was clarified by LightCycler Real Time PCR.The expression of Scnpr1 was regulated by signal molecules MJ,ET,SA,and upregulated when treated with the pathogens of Erysiphe cichoracearum,Rhizoctonia cerealis and Fusarium graminearum.The results indicated that Scnpr1 gene was the homologous gene of NPR1 gene in Secale Cereale.The expression of Scnpr1 gene was relevant to ET and SA signal transduction pathways,and it potentially involved in host defense responses to wheat pathogen.