He C, Xie W, Yang X, Wang S-L, Wu Q-J, Zhang Y-J
College of Plant Protection of Hunan Agricultural University, Changsha, China.
Department of Plant Protection, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China.
Insect Mol Biol. 2018 Feb;27(1):22-35. doi: 10.1111/imb.12337. Epub 2017 Aug 2.
The Bemisia tabaci (Gennadius) (Hemiptera:Aleyrodidae) species complex includes invasive and destructive pests of field crops, and the sibling species MEAM1 and MED are its two most damaging members. Previous research indicated that the replacement of Middle East-Minor Asia 1 (MEAM1) by Mediterranean (MED) as the dominant B. tabaci species in China can be mainly attributed to MED's greater tolerance to insecticides. Glutathione S-transferases (GSTs) play important roles in the detoxification of hydrophobic toxic compounds. To increase our understanding of differences in insecticide resistance between B. tabaci MEAM1 and MED, we searched the genomic and transcriptomic databases and identified 23 putative GSTs in both B. tabaci MEAM1 and MED. Through measuring mRNA levels of 18 of the GSTs after B. tabaci MEAM1 and MED adults were exposed to the insecticide imidacloprid, we found that the expression levels were increased more in B. tabaci MED than in MEAM1 (in particular, the expression level of GST-d7 was increased by 4.39-fold relative to the control). Knockdown of GST-d7 in B. tabaci MED but not in B. tabaci MEAM1 resulted in a substantial increase in the mortality of imidacloprid-treated adults. These results indicate that differences in GST-d7 may help explain why insecticide tolerance is greater in B. tabaci MED than in B. tabaci MEAM1.
烟粉虱（Bemisia tabaci (Gennadius)，半翅目：粉虱科）物种复合体包含田间作物的入侵性和破坏性害虫，其同胞物种MEAM1和MED是危害最大的两个成员。先前的研究表明，在中国，地中海烟粉虱（MED）取代中东-小亚细亚1型烟粉虱（MEAM1）成为优势烟粉虱物种，主要归因于MED对杀虫剂具有更强的耐受性。谷胱甘肽S-转移酶（GSTs）在疏水性有毒化合物的解毒过程中发挥着重要作用。为了加深我们对烟粉虱MEAM1和MED在杀虫剂抗性方面差异的理解，我们搜索了基因组和转录组数据库，并在烟粉虱MEAM1和MED中鉴定出23个假定的GSTs。通过测量烟粉虱MEAM1和MED成虫接触杀虫剂吡虫啉后18个GSTs的mRNA水平，我们发现烟粉虱MED中的表达水平比MEAM1中的增加得更多（特别是，GST-d7的表达水平相对于对照增加了4.39倍）。在烟粉虱MED中敲低GST-d7，但在烟粉虱MEAM1中不敲低，导致吡虫啉处理的成虫死亡率大幅增加。这些结果表明，GST-d7的差异可能有助于解释为什么烟粉虱MED比烟粉虱MEAM1对杀虫剂的耐受性更强。
