中文摘要：

淀粉酶产色链霉菌Streptomyces diastatochromogenes 1628是一株重要的生防菌株,其代谢产物对多种植物病原真菌具有较强的抑制效果。为了筛选在其不同抗药性高产突变株中均能稳定表达的内参基因,选择16S rRNA、sigB、hrdB、thyA、gyrB和rpoA共6个常见内参基因,分别探究它们在野生型菌株、链霉素抗性突变株、利福平抗性突变株和巴龙霉素抗性突变株中的表达情况,并用geNorm软件和NormFinder软件对结果进行分析。结果表明,使用不同软件分析得出的最佳内参基因略有差异。geNorm软件认为在上述4株菌株中,表达最稳定的内参基因分别是gyrB、gyrB、thyA、rpoA;而NormFinder软件认为rpoA基因在所有菌株的表达都是最稳定的。利用平均等级的算法平衡两个软件的分析差异,最终确定rpoA基因为表达最稳定的内参基因。通过检测toyG基因的表达水平,发现以rpoA作为内参基因能得到更合理的结果。

英文摘要：

Metabolites of Streptomyces diastatochromogenes 1628 have strong inhibition on various plant pathogenic fungi. To screen out the most stably expressed endogenous reference genes in different drug resistance overproduction mutants of S. diastatochromogenes 1628, six candidate reference genes were selected for real-time quantitative PCR, and two kinds of software were adopted to determine the stability of candidate reference genes in different drug resistance strains. The results revealed that the optimum reference gene analyzed by different softwares was slightly different. Analysis of geNorm software showed the gyrB, gyrB, thyA, rpoA were the most stably expressed reference gene in wild-type, streptomycin-resistance, rifampin-resistance and paromomycin- resistance strain, respectively. However, rpoA was the most stable gene in tested strains analyzed by NormFinder. Comprehensively, the mean rank based on stability banking analyzed by these two kinds of software showed that rpoA was the most suitable reference gene in all tested strains. By detecting the expression level of toyG gene, it was found that rpoA as intemal control gene is more reasonable.