CMV 通过影响效应因子 MpC002 的表达干预桃蚜种群 增长的机制.

【Objective】 Peach aphid (Myzus persicae) is an important vector of cucumber mosaic virus (CMV), and the effector MpC002 plays a key role in the feeding process. CMV and MpC002 are both present in aphid saliva, but little is known about their interaction and how MpC002 facilitate virus transmission. Therefore, this study aims to preliminarily investigate the mechanism by which CMV influences the expression of MpC002 for interfering the population growth of GPA. .【Method】 The CMV copy number was calculated by the standard curve y=-3.163 1x+39.763, via applying the absolute quantitative polymerase chain reaction (qPCR) 【Result】 The CMV content in the peach aphid fed with CMV-infected pepper reached the highest at 10 s, then the CMV content decreased gradually along with the feeding time, and its virulence acquisition process conformed to the characteristics of non-persistent transmission. In addition, the expressions of MpC002 in the peach aphids fed on CMV-infested peppers within 5 min-24 h significantly decreased to 37%-58%, compared with those before feeding. While feeding on CMV-infested peppers, the average developmental duration of third, fourth instar and the entire nymph stages were 1.58, 2.07 and 6.47 d, which were significantly longer than those fed on the untreated peppers (1.25 d, 1.47 d and 5.33 d) ; in contrast, the developmental duration of the first and second instars did not show significantly difference between CMV-infested and untreated peppers. The average laying period, the total peach aphid number and the average peach aphid in a single day were 10.03 d, 16.87 and 1.67, which were significantly shorter than those of untreated peppers (14.27 d, 39.73 and 2.82) . In addition, analysis of GPA life table parameters revealed that the net growth rate, intrinsic rate of increase, and finite rate of increase were 16.87, 0.21, and 1.21, respectively, which were significantly lower than those of peach aphids feeding on untreated peppers (39.73, 0.31, and 1.36, respectively), whereas the mean generation time (13.02 d) and the population doubling time (3.26 d) were both significantly longer than those of peach aphids feeding untreated peppers (12.00 d and 2.30 d) .【Conclusion】CMV significantly inhibited the expressions of MpC002, and then prolongated the developmental duration and decreased the reproduction, which in turn adversely affected its population growth. [ABSTRACT FROM AUTHOR]

【目的】桃蚜是 CMV 的重要传毒媒介，效应因子 MpC002 在桃蚜取食寄主过程中发挥关键作用，CMV 和 MpC002 均存在于蚜虫唾液中，但两者如何相互作用从而利于病毒传播知之甚少。为探讨 CMV 影响 MpC002 表达干预桃蚜种群增长的机制。 【方法】利用绝对定量的 qPCR 法建立 CMV 拷贝数检测的标准曲线方程 y=-3.163 1x+39.763。【结果】桃蚜取食 CMV 感染辣椒 10 s 体内 CMV 含量最高，然后随着取食时间的延长 CMV 含量不断降低，其获毒过程符合非持久性传毒特征。取食 CMV 感染辣椒 5 min-24 h 的桃蚜 MpC002 表达量显著降低至取食前的 37%-58% ；取食 CMV 感染辣椒的 3 龄、4 龄若蚜和 1-4 龄若蚜的平均发育历 期分别为 1.58 d、2.07 d 和 6.47 d，显著长于取食未处理辣椒的 1.25 d、1.47 d 和 5.33 d，但 1 龄和 2 龄若蚜发育历期在 CMV 感染 辣椒和未处理辣椒间无显著差异 ；平均产蚜期、总产蚜量和单日平均产蚜量分别为 10.03 d、16.87 头和 1.67 头，显著短于取食未 处理辣椒桃蚜的 14.27 d，39.73 头和 2.82 头 ；净增殖率、内禀增长率、周限增长率分别为 16.87、0.21、1.24，均显著低于取食未 处理辣椒桃蚜的 39.73、0.31、1.36，平均世代周期（13.02 d）和种群加倍时间（3.26 d）均显著长于取食未处理辣椒桃蚜的 12.00 d 和 2.30 d。【结论】CMV 能显著抑制桃蚜 MpC002 的表达，从而延长其发育历期和降低其繁殖，最终抑制其种群的增长。 [ABSTRACT FROM AUTHOR]