title: Down-regulation of a novel ABC transporter gene (Pxwhite) is associated with Cry1Ac resistance in the diamondback moth, Plutella xylostella (L.).
abstract: Biopesticides or transgenic crops based on Cry toxins from the soil bacterium Bacillus thuringiensis (Bt) effectively control agricultural insect pests. The sustainable use of Bt biopesticides and Bt crops is threatened, however, by the development of Cry resistance in the target pests. The diamondback moth, Plutella xylostella (L.), is the first pest that developed resistance to a Bt biopesticide in the field, and a recent study has shown that the resistance of P. xylostella to Cry1Ac is caused by a mutation in an ATP-binding cassette (ABC) transporter gene (ABCC2). In this study, we report that down-regulation of a novel ABC transporter gene from ABCG subfamily (Pxwhite) is associated with Cry1Ac resistance in P. xylostella. The full-length cDNA sequence of Pxwhite was cloned and analyzed. Spatial-temporal expression detection revealed that Pxwhite was expressed in all tissues and developmental stages, and highest expressed in Malpighian tubule tissue and in egg stage. Sequence variation analysis of Pxwhite indicated the absence of constant non-synonymous mutations between susceptible and resistant strains, whereas midgut transcript analysis showed that Pxwhite was remarkably reduced in all resistant strains and further reduced when larvae of the moderately resistant SZ-R strain were subjected to selection with Cry1Ac toxin. Furthermore, RNA interference (RNAi)-mediated suppression of Pxwhite gene expression significantly reduced larval susceptibility to Cry1Ac toxin, and genetic linkage analysis confirmed that down-regulation of Pxwhite gene is tightly linked to Cry1Ac resistance in P. xylostella. To our knowledge, this is the first report indicating that Pxwhite gene is involved in Cry1Ac resistance in P. xylostella.
authors: Department of Plant Protection, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China. Electronic address: zjguo1988@163.com.
authors: Zhaojiang
authors: Z
authors: Guo
authors: Department of Plant Protection, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China. Electronic address: kangshi0718@163.com.
authors: Shi
authors: S
authors: Kang
authors: Department of Plant Protection, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China. Electronic address: zhuxun99@gmail.com.
authors: Xun
authors: X
authors: Zhu
authors: Department of Plant Protection, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China. Electronic address: jixingxia@126.com.
authors: Jixing
authors: J
authors: Xia
authors: Department of Plant Protection, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China. Electronic address: wuqingjun@caas.cn.
authors: Qingjun
authors: Q
authors: Wu
authors: Department of Plant Protection, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China. Electronic address: wangshaoli@caas.cn.
authors: Shaoli
authors: S
authors: Wang
authors: Department of Plant Protection, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China. Electronic address: xiewen@caas.cn.
authors: Wen
authors: W
authors: Xie
authors: Department of Plant Protection, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China. Electronic address: zhangyoujun@caas.cn.
authors: Youjun
authors: Y
authors: Zhang
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D001413:Bacillus thuringiensis / Q000201:enzymology*; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000378:metabolism* / Q000633:toxicity; D001427:Bacterial Toxins / Q000378:metabolism; D004064:Digestive System / Q000378:metabolism; D015536:Down-Regulation; D004731:Endotoxins / Q000378:metabolism* / Q000633:toxicity; D006460:Hemolysin Proteins / Q000378:metabolism* / Q000633:toxicity; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism*; D007814:Larva / Q000187:drug effects / Q000378:metabolism; D009036:Moths / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D034622:RNA Interference
chemical_list: D018528:ATP-Binding Cassette Transporters; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004731:Endotoxins; D006460:Hemolysin Proteins; D019476:Insect Proteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis
keywords: ABC transporter; Bacillus thuringiensis; Cry1Ac resistance; Plutella xylostella; Pxwhite gene