Downregulation and mutation of a Cadherin gene associated with Cry1Ac resistance in the Asian Corn Borer, Ostrinia furnacalis (Guenée).
Downregulation and mutation of a Cadherin gene associated with Cry1Ac resistance in the Asian Corn Borer, Ostrinia furnacalis (Guenée).
复制标题
作者：
Jin T;Chang X;Gatehouse AM;Wang Z;Edwards MG;He K
目标害虫产生抗药性是长期使用表达苏云金芽孢杆菌 (Bt) Cry 毒素的转基因作物的主要威胁。为了通过实施有效的策略来管理和/或延迟目标昆虫的抗性进化，有必要了解抗性的基础。昆虫对 Bt 作物产生抗性的最重要机制之一是 Cry 毒素与其中肠受体之间相互作用的改变。 Cry1Ac 选择的亚洲玉米螟 (ACB) 菌株，亚洲玉米螟 (Ostriniafurnacalis)，中国玉米的主要害虫，进化出了钙粘蛋白样蛋白 (OfCAD) 的三个突变等位基因 (MPR-r1、MPR-r2 和 MPR-r3)，这些基因位于毒素结合区 (TBR) 内。三个突变等位基因均在该区域具有两个或三个氨基酸取代，尤其是 Thr1457→Ser。在高抗性幼虫（ACB-Ac200）中，MPR-r2 在 TBR 中缺失了 26 个氨基酸残基，与易感菌株的 MPR 相比，这导致 Cry1Ac 的结合减少，表明氨基酸缺失的数量影响抗性水平。此外，在 Cry1Ac 抗性菌株 ACB-Ac24 中观察到 OfCAD 基因 (ofcad) 转录下调，表明 ACB 中的 Cry1Ac 抗性与钙粘蛋白样蛋白基因转录水平的下调相关。从 ACB 中鉴定出的 OfCAD 与鳞翅目物种中钙粘蛋白超家族的其他成员表现出高度相似性。
Development of resistance in target pests is a major threat to long-term use of transgenic crops expressing Bacillus thuringiensis (Bt) Cry toxins. To manage and/or delay the evolution of resistance in target insects through the implementation of effective strategies, it is essential to understand the basis of resistance. One of the most important mechanisms of insect resistance to Bt crops is the alteration of the interactions between Cry toxins and their receptors in the midgut. A Cry1Ac-selected strain of Asian corn borer (ACB), Ostrinia furnacalis, a key pest of maize in China, evolved three mutant alleles of a cadherin-like protein (OfCAD) (MPR-r1, MPR-r2 and MPR-r3), which mapped within the toxin-binding region (TBR). Each of the three mutant alleles possessed two or three amino acid substitutions in this region, especially Thr1457→Ser. In highly resistant larvae (ACB-Ac200), MPR-r2 had a 26-amino acid residue deletion in the TBR, which resulted in reduced binding of Cry1Ac compared to the MPR from the susceptible strain, suggesting that the number of amino acid deletions influences the level of resistance. Furthermore, downregulation of OfCAD gene (ofcad) transcription was observed in the Cry1Ac resistant strain, ACB-Ac24, suggesting that Cry1Ac resistance in ACB is associated with the downregulation of the transcript levels of the cadherin-like protein gene. The OfCAD identified from ACB exhibited a high degree of similarity to other members of the cadherin super-family in lepidopteran species.
登录
查看更多内容
通过可溶性毒素结合钙粘蛋白片段减少苏云金芽孢杆菌 Cry1Ac 对棉铃虫的毒性
影响因子：
2.2
作者：
Liu, Chenxi;Wu, Kongming;Oppert, Brenda
通讯作者：
Oppert, Brenda
影响因子：
2.9
作者：
Hua, Gang;Zhang, Rui;Adang, Michael J.
通讯作者：
Adang, Michael J.
影响因子：
2.2
作者：
Li, Guo-Ping;Wu, Kong-Ming;Guo, Yu-Yuan
通讯作者：
Guo, Yu-Yuan
影响因子：
2.2
作者：
Huang, FN;Higgins, RA;Buschman, LL
通讯作者：
Buschman, LL
影响因子：
3.4
作者：
Braun, L;Keddie, BA
通讯作者：
Keddie, BA