小麦TcLr19PR2基因在茉莉酸甲酯、乙烯及叶锈菌胁迫下的表达分析

Expression Analysis of TcLr19PR2 Gene in Wheat TcLr19 Induced by MeJA,ETH and Puccinia triticina

为揭示小麦TcLr19PR2基因在信号分子和叶锈菌诱导下的表达情况，利用半定量RT-PCR方法分析了不同浓度茉莉酸甲酯（MeJA）和乙烯（ETH）诱导后于不同时间点该基因表达模式，明确MeJA和ETH最佳诱导浓度及诱导时间，同时分析了MeJA和ETH预处理后于不同时期接种叶锈菌后该基因在小麦中的表达特征。结果表明，MeJA和ETH的最佳诱导浓度分别为0．1和1．0mmol·L^-1。接种叶锈菌后，TeLr19PR2基因表达量在MeJA诱导后0～3d都有明显上调，并在MeJA预处理3d后接种叶锈菌24h时TcLr19PR2基因表达量达到最大，基因表达峰值的出现要早于未接菌处理；ETH预处理3d后接种叶锈菌24h时TcLr19PR2基因表达水平开始升高，预处理10d后，接菌处理的各时间点均高于未接菌处理。以上结果说明，叶锈菌和信号分子协同作用能够显著诱导TcLr19PR2基因的表达，共同参与小麦品系TcLr19的抗叶锈病防御反应。

In order to identify the expression profiles of a full length β-1, 3-glucanase gene, TcLr19PR2, induced by different chemical molecule and leaf rust pathogen, the gene expression levels of TcLr19PR2 induced by the optimal concentrations Methyl jasmonate（MeJA） and Ethylene（ETH） were analysed using semi-quantitative RT-PCR with TcLr19 as experiment material. These results suggested that the optimal concentrations were 0. 1 mmol · L^-1 for MeJA and 1.0 mmol · L^-1 for ETH, respectively. MeJA pre-treatment prior to infection resulted in a steady increase in TaLr19PR2 expression from 0 to 3 days post inoculation（dpi）, and reached the peak at 24 hour post inoculation （hpi）, which appeared earlier than that in the Mock （non-inoculation）. The expression level of TcLr19PR2 increased at 24 hpi after ETH pre-treatment prior to infection, and higer than that in Mock at 10 dpi after ETH pre-treatment prior to infection. All these results proved that the expression of TcLrl9PR2 was induced by P. triticina and signaling molecules together, which might he involved in the defense reaction to P. triticina of TcLr19.