为深入理解杀虫剂胁迫对烟粉虱Bemisia tabaci适应逆境能力的影响,本研究运用实时荧光定量PCR技术测定了LC25,LC50和LC753种浓度的烯啶虫胺、毒死蜱和高效氯氰菊酯分别处理对烟粉虱地中海隐种B.tabaci Mediterranean成虫体内热激蛋白hsp70表达水平的影响。结果表明:在低温(15℃)条件下,LC50和LC75的烯啶虫胺、毒死蜱、高效氯氰菊酯可显著诱导烟粉虱地中海隐种hsp70的表达量增加,此后随时间延长hsp70表达量逐渐下降,到72h时恢复到对照水平,但LC25的3种杀虫剂对hsp70的表达无明显影响;在常温(25℃)下,较高浓度(LC50和LC75)的烯啶虫胺、毒死蜱和高效氯氰菊酯处理24h同样可促进hsp70表达量的增加,然后hsp70表达量逐渐下降,到72h时恢复至正常水平,但低浓度(LC25)的3种药剂处理后hsp70表达量随时间延长而增加,到72h时达到最高;在高温(32℃)条件下,LC25和LC50的烯啶虫胺、毒死蜱和高效氯氰菊酯处理24h可显著增强hsp70的表达水平,此后随时问的延长hsp70表达恢复至正常水平。杀虫药剂诱导的hsp70表达量增加增强了烟粉虱地中海隐种对杀虫药剂和高温的耐受能力,这可能是导致其在我国快速扩张的原因之一。
Abstract: To understand the effects of insecticides on the adaption of the white fly Bemisia tabaci Mediterranean to stress environment, the expression of the heat shock protein gene hsp70 in this whitefly was investigated using real-time quantitative PCR after treatment with LC25, LC50 and LC70 of nitenpyram, chlorpyrifos and beta-cypermethrin, respectively, at different temperatures. The results showed that at the lower temperature ( 15℃ ) the treatments of the three insecticides at LC50 and LC75 for 24 h significantly induced an increase in the expression level of hsp70, and then the expression was decreased gradually and showed no difference from the untreated control at 72 h after treatment; the three insecticides at LC25, however, showed no effect on the expression of hsp70. At room temperature (25℃ ), nitenpyram, chlorpyrifos and beta-cypermethrin at LC50 and LC75 induced the expression of hsp70 significantly at 24 h after treatment, and then the expression levels were decreased gradually to the normal level at 72 h after treatment; the three insecticides at LC25, however, induced an increased expression of hsp70 with the treatment time. At a higher temperature (32℃), nitenpyram, chlorpyrifos and cypermethrin at LC25 and LC50significantly induced the expression of hsp70 at 24 h after treatment and the expression levels were then decreased and showed no difference from the control at 72 h after treatment. The high-level expression of hsp70 induced by insecticides enhances the tolerance of the whitefly to insecticides and high temperature, which may be one of the reasons that this whiteflv expanded quickly in China.