Wang Hongmin, Li He, Zhang Tianhao, Zhang Xianhong
College of Economics and Management, Shanxi Agricultural University, Taigu 030801, Shanxi, China.
College of Agriculture, Shanxi Agricultural University, Taigu 030801, Shanxi, China.
Sheng Wu Gong Cheng Xue Bao. 2019 Jan 25;35(1):114-120. doi: 10.13345/j.cjb.180131.
Serine elastic chymotrypsin Pr1 is an enzyme that efficiently degrades insect body wall protein through its connection with the virulence of entomogenous fungi. Therefore, it is important to explore the relationship between the Pr1 protease activity, the Pr1 gene expression and the virulence of different strains of entomogenous fungi. Specific peptide substrate Suc-Ala-Ala-Pro-Phe-pNA and fluorogenic quantitative PCR were used for detecting Pr1 protease activity and Pr1 gene expression, and the slope spray method was used for evaluating the virulence of the fungi on the Myzus persicae. The results indicated that the linear regression equation of the Pr1 protease activity and the virulence of different strains were: y=3.64x+0.62, R²=0.432. It was shown that there is a positive correlation between the Pr1 protease activity and virulence of different strains. Moreover, the result of the multiple linear regression analysis between Pr1 protease activity, Pr1 gene expression and the virulence of different strains was: y=0.236+10.833x₁-0.039x₂ (x₁ represents Pr1 protease activity while x₂ represents Pr1 gene expression), R²=0.568, which suggested that the raw data could be represented by a linear fitting equation. The serial correlation coefficient was high (D-W was 2.444), indicating that Pr1 protease activity and Pr1 gene expression have great effect on the virulence of the fungi. Additionally, VIF=12.705, which shows that moderate multiple collinear exists between Pr1 protease activity and Pr1 gene expression. Therefore, Pr1 protease activity and Pr1 gene expression could be recommended as important indicators for strain virulence selection.
丝氨酸弹性胰凝乳蛋白酶Pr1是一种通过与虫生真菌的毒力相关联而有效降解昆虫体壁蛋白的酶。因此，探究不同虫生真菌菌株的Pr1蛋白酶活性、Pr1基因表达与毒力之间的关系具有重要意义。采用特异性肽底物Suc-Ala-Ala-Pro-Phe-pNA和荧光定量PCR检测Pr1蛋白酶活性和Pr1基因表达，并用点滴喷雾法评估真菌对桃蚜的毒力。结果表明，不同菌株的Pr1蛋白酶活性与毒力的线性回归方程为：y = 3.64x + 0.62，R² = 0.432。结果表明，不同菌株的Pr1蛋白酶活性与毒力之间存在正相关。此外，Pr1蛋白酶活性、Pr1基因表达与不同菌株毒力的多元线性回归分析结果为：y = 0.236 + 10.833x₁ - 0.039x₂（x₁代表Pr1蛋白酶活性，x₂代表Pr1基因表达），R² = 0.568，这表明原始数据可用线性拟合方程表示。序列相关系数较高（D-W为2.444），表明Pr1蛋白酶活性和Pr1基因表达对真菌毒力有很大影响。此外，VIF = 12.705，表明Pr1蛋白酶活性和Pr1基因表达之间存在中度多重共线性。因此，Pr1蛋白酶活性和Pr1基因表达可作为菌株毒力筛选的重要指标。
