中文摘要：

AtNPR1是拟南芥系统获得性抗病反应中的关键基因,对拟南芥的广谱抗性起重要调控作用。从赤霉菌诱导的小麦抗、感赤霉病近等基因系RNA差异表达谱中获得3个与AtNPR1类似的EST片段,据此检索相应序列信息并设计引物,从小麦中克隆得到3个cDNA全长序列,分别命名为TaNPR1、TaNPR2和TaNPR3,其开放阅读框分别编码580、607和601个氨基酸残基。序列分析表明,这3个小麦NPR1-like蛋白都含有保守的BTB/POZ、ANK和NPR1_like_C结构域及功能氨基酸,但仅TaNPR1具有2个对NPR1寡聚体形成十分必要的保守半胱氨酸残基。蛋白质聚类分析表明,TaNPR1与TaNPR2和TaNPR3的同源性均较低,其中TaNPR1与NPR1蛋白聚为一类,而TaNPR2和TaNPR3均与NPR1同源蛋白聚为一类。实时荧光定量PCR分析结果显示,TaNPR1、TaNPR2和TaNPR3基因都可被植物抗病相关信号分子水杨酸和茉莉酸甲酯诱导。与感病材料Apogee相比,抗病近等基因系Apogee73S2中TaNPR1和TaNPR3能够更早地响应赤霉菌的诱导并显著上调表达;而TaNPR2在感、抗材料中对赤霉菌侵染的响应都较为缓慢且变化不明显。这些结果表明,TaNPR1和TaNPR3可能在小麦对赤霉菌的防御反应中起重要作用。

英文摘要：

NPR1 gene plays a key role for systemic acquired resistance（SAR）and provides broad-spectrum resistance in Arabidopsis.Fusarium head blight（FHB）,which is caused by Fusarium graminearum Schwabe,is a devastating disease of wheat worldwide.Based on the analysis of the gene expression profiling,we cloned three NPR1-like genes from wheat FHB near-isogenic lines induced by F.graminearum,and they were designated as TaNPR1,TaNPR2,and TaNPR3.The open reading frames of the three genes encoded 580,607,and 601 amino acid residues,respectively.The three wheat NPR1-like proteins had conversed BTB/POZ,ANK,and NPR1_like_C domain as well as conversed amino acid residues with important functions.However,only TaNPR1 had two conversed cysteine residues that are essential for the NPR1 oligomer formation.Phylogenetic analysis showed that TaNPR1 was involved in the NPR1 protein group,while TaNPR2 and TaNPR3 were close to NPR1 homologues.Quantitative RT-PCR assay revealed that the three NPR1-like genes could be induced by defense related signal molecules,such as salicylic acid and methyl jasmonate.TaNPR1 and TaNPR3 were induced earlier and up-regulated more significantly in response to F.graminearum infection in the resistant line Apogee73S2 than in the susceptible line Apogee.However,the transcription of TaNPR2 was not obviously changed in either the resistant or susceptible near-isogenic lines after inoculation with F.graminearum.These results suggest that TaNPR1 and TaNPR3 may be involved in the defense response to F.graminearum.