蛹虫草和蝉棒束孢组氨酸激酶基因受杀菌剂影响的差异表达

Differential expression of histidine kinase genes in Cordyceps militaris and Isaria cicadae in responses to different fungicides

组氨酸激酶是真菌感受外界刺激的重要组成部分,它使真菌能适应和应答环境的改变。通过RT‐PCR克隆蝉棒束孢Isaria cicadae组氨酸激酶基因Ic HK的ORF序列,对Ic HK基因序列分析表明其翻译产物Ic HK中存在着4个HAMP功能域、1个His KA功能域、1个HATPase功能域和1个REC功能域。采用实时荧光定量PCR方法研究了3种杀菌剂咯菌腈(Fludioxonil)、异菌脲(Iprodione)和克菌丹(Captan)对蛹虫草Cordyceps militaris组氨酸激酶Cm HK和蝉棒束孢组氨酸激酶Ic HK表达的影响。结果表明,Cm HK基因的表达对这3种杀菌剂的影响不敏感,这3种杀菌剂不能导致Cm HK基因的相对转录量明显增加。Ic HK基因的表达对这3种杀菌剂的影响都敏感,特别是对咯菌腈和克菌丹更为敏感,这3种杀菌剂可导致Ic HK基因的相对转录量的增加。研究结果表明不同真菌应对相同胁迫环境时,同源基因的表达特征可存在差异。

Histidine kinase is an important part of the mechanism that fungus feel the external stimuli, which enable fungi to respond and adapt to the environmental changes. The histidine kinase gene of Isaria cicadae was obtained by RT-PCR, and the bioinformatics analysis of the translation products of IcHK gene showed that there were four HAMP domains, one HisKA domain, one HATPase domain and one REC domain in IcHK sequence. Real-time PCR method was used to study the effect of three kinds of fungicide, fludioxonil, iprodione and captan, on the expression of Cordyceps militaris histidine kinase gene CmHK and Isario cicadae histidine kinase gene IcHK. The results show that the expression of CmHK gene is not susceptible to the three kinds of fungicides, which cannot result in significant increases of the relative transcription level of CmHK gene. The expression of IcHK gene is susceptible to the three kinds of fungicides, especially fludioxonil and captan, and the three kinds of fungicides can lead to the increases of relative transcription level of IcHK gene. The results indicated that the homologous genes could be differentially transcribed by different fungi in response to the same stress factors .