Xiao Da, Lu Yan-Hui, Shang Qing-Li, Song Dun-Lun, Gao Xi-Wu
Department of Entomology, China Agricultural University, Beijing, China.
Pest Manag Sci. 2015 Apr;71(4):523-30. doi: 10.1002/ps.3800. Epub 2014 May 12.
The function of acetylcholinesterase (AChE) is to terminate synaptic transmission by hydrolysing the neurotransmitter acetylcholine (ACh) in the synaptic cleft, and thus it is an effective target for organophosphate (OP) and carbamate (CB) insecticides.
The transcript levels of the four Ace genes were dramatically suppressed by injection of their respective dsRNA in Rhopalosiphum padi and Sitobion avenae. However, the AChE activity changes in the Ace1 knockdown aphids were consistent with the significant transcript level changes of Ace1 genes in these aphids, but not for Ace2. Bioassay results indicated that the suppression of RpAce1 increased its susceptibilities to pirimicarb and malathion, and SaAce1 silencing also increased susceptibility to pirimicarb in S. avenae, whereas the knockdowns of RpAce2 and SaAce2 had a slight effect on their susceptibilities. The knockdown of Ace1 genes also caused significant reductions in fecundity in the aphids of their parental generation.
These results suggest that AChE1 is a predominant cholinergic enzyme and is the target of anticholinesterase insecticides in both R. padi and S. avenae. It also plays a non-cholinergic role in fecundity of these aphids. AChE2 may also be important for the toxicological function, although its importance appeared to be lower than that of AChE1.
乙酰胆碱酯酶（AChE）的功能是通过水解突触间隙中的神经递质乙酰胆碱（ACh）来终止突触传递，因此它是有机磷酸酯（OP）和氨基甲酸酯（CB）类杀虫剂的有效作用靶点。
在禾谷缢管蚜和麦长管蚜中，通过注射各自的dsRNA可显著抑制四个Ace基因的转录水平。然而，Ace1基因敲低的蚜虫中AChE活性变化与这些蚜虫中Ace1基因显著的转录水平变化一致，但Ace2基因敲低的蚜虫并非如此。生物测定结果表明，禾谷缢管蚜RpAce1的抑制增加了其对抗蚜威和马拉硫磷的敏感性，麦长管蚜中SaAce1的沉默也增加了其对抗蚜威的敏感性，而禾谷缢管蚜RpAce2和麦长管蚜SaAce2的敲低对其敏感性影响较小。Ace1基因的敲低还导致其亲代蚜虫的繁殖力显著下降。
这些结果表明，AChE1是主要的胆碱能酶，是禾谷缢管蚜和麦长管蚜中抗胆碱酯酶杀虫剂的作用靶点。它在这些蚜虫的繁殖中也发挥非胆碱能作用。AChE2可能对毒理学功能也很重要，尽管其重要性似乎低于AChE1。
