检测和分析核糖核酸还原酶大亚基（RNR-LC）基因、小亚基（RNR-M2）基因在不同蛹虫草菌株中mRNA的相对表达量与虫草素含量的变化关系，探究核糖核酸还原酶在虫草素合成途径中的转录调控作用。检测不同蛹虫草菌株虫草素含量，采用荧光PCR技术对蛹虫草RNR-LC基因、RNR-M2基因表达的mRNA进行定量分析，并应用双内参基因对试验数据进行校正。以虫草素含量最低的野生蛹虫草组为对照，米基虫草组RNR-LC、RNR-M2基因的mRNA表达量分别是野生蛹虫草组的1.28倍和1.47倍，蚕蛹虫草组分别是其2.35倍和3.84倍。与对照组相比，RNR-M2 mRNA表达随虫草素的增加总体呈现升高的变化规律。两种基因在不同蛹虫草菌株中的相对表达量存在显著性差异（p<0.05）。RNR-M2基因在高虫草素菌株中存在明显的表达优势，而RNR-LC基因表达量与虫草素含量无明显变化关系，二者不存在协同调控作用。推测RNR-M2基因在虫草素合成途径中起着重要的正向调控作用。

The relationships between relative mRNA expression levels of the large ribonuclease reductase subunit (RNR-LC) and small subunit (RNR-M2) genes and cordycepin content in different Cordyceps militaris strains were determined and analyzed to investigate the transcriptional regulation of the cordycepin synthesis pathway by RNR. Cordycepin content in various C. militaris strains was measured, and quantitative analysis of mRNA expressed by the RNR-LC and RNR-M2 genes was performed by quantitative fluorescent PCR with the use of two internal control genes for experimental data correction. Wild C. militaris, which had the lowest cordycepin content, was used as control. Results indicated that mRNA expression levels of the RNR-LC and RNR-M2 genes in the rice-cultivated C. militaris group were 1.28 and 1.47 times that of the control group, respectively. The corresponding mRNA expression levels of the silkworm chrysalis-cultivated C. militaris group were 2.35 and 3.84 times that of the control group, respectively. Compared with the control group, the mRNA expression level of RNR-M2 generally increased with an increase in cordycepin content. There were significant differences in the relative expression levels of both genes among different C. militaris strains (p<0.05). Obvious dominant expression of the RNR-M2 gene was observed in strains with high cordycepin content, while the expression level of the RNR-LC gene did not change significantly with cordycepin content. Therefore, a synergistic regulatory role does not exist between the two genes. It can be deduced that the RNR-M2 gene plays a key role in the positive regulation of the cordycepin synthesis pathway.

吉林省科技发展计划项目(20190301014NY；20190304101YY；20190902018TC)；北华大学研究生创新计划(北华研创合字[2018]040；北华研创合字[2018]037)