Introgression of a disrupted cadherin gene enables susceptible Helicoverpa armigera to obtain resistance to Bacillus thuringiensis toxin Cry1Ac.
Introgression of a disrupted cadherin gene enables susceptible Helicoverpa armigera to obtain resistance to Bacillus thuringiensis toxin Cry1Ac.
复制标题
DOI：
10.1017/s0007485308006226
复制
发表时间：
2009-04
影响因子：
1.9
通讯作者：
Y-H Yang;Y-J Yang;W. Gao;J.-J. Guo-J.;Y.‐H. Wu;Y-D Wu
中科院分区：
文献类型：
--
作者：
Y-H Yang;Y-J Yang;W. Gao;J.-J. Guo-J.;Y.‐H. Wu;Y-D Wu
棉铃虫（Helicoverpaarmigera）的钙粘蛋白基因（Ha_BtR）的一个被破坏的等位基因（r1）与对苏云金芽孢杆菌毒素Cry 1Ac的不完全隐性抗性相关。通过GYBT株系与SCD株系杂交，再与SCD株系反复回交，利用分子标记辅助家系选择，将Ha_BtR的r1等位基因渗入感病SCD株系。导入菌株（SCD-r1，携带纯合r1等位基因）对Cry 1Ac的抗性是SCD菌株的438倍，对Cry 1Aa的抗性是SCD菌株的41倍，对Cry 1Ab的抗性是SCD菌株的31倍，但对Cry 2Aa的敏感性与亲本菌株无显著差异。这证实了Ha_BtR单独的功能缺失突变可以赋予H. armigera。SCD和SCD-r1株系间的正反交试验表明，SCD-r1株系对Cry 1Ac的抗性为完全隐性。构建了SCD和SCD-r1菌株在实验室人工饲料中的生命表，结果表明，菌株之间的净替代率（R 0）没有差异。氰戊菊酯和久效磷两种化学杀虫剂对SCD-r1菌株和SCD菌株的毒力差异不显著。然而，SCD-r1菌株的幼虫发育时间显著长于SCD菌株，表明在H. armigera。
A disrupted allele (r1) of a cadherin gene (Ha_BtR) is genetically associated with incompletely recessive resistance to Bacillus thuringiensis toxin Cry1Ac in a Cry1Ac-selected strain (GYBT) of Helicoverpa armigera. The r1 allele of Ha_BtR was introgressed into a susceptible SCD strain by crossing the GYBT strain to the SCD strain, followed by repeated backcrossing to the SCD strain and molecular marker assisted family selection. The introgressed strain (designated as SCD-r1, carrying homozygous r1 allele) obtained 438-fold resistance to Cry1Ac, >41-fold resistance to Cry1Aa and 31-fold resistance Cry1Ab compared with the SCD strain; however, there was no significant difference in susceptibility to Cry2Aa between the integrated and parent strains. It confirms that the loss of function mutation of Ha_BtR alone can confer medium to high levels of resistance to the three Cry1A toxins in H. armigera. Reciprocal crosses between the SCD and SCD-r1 strains showed that resistance to Cry1Ac in the SCD-r1 strain was completely recessive. Life tables of the SCD and SCD-r1 strains on artificial diet in the laboratory were constructed, and results showed that the net replacement rate (R0) did not differ between the strains. The toxicity of two chemical insecticides, fenvalerate and monocrotophos, against the SCD-r1 strain was not significantly different from that to the SCD strain. However, larval development time of the SCD-r1 strain was significantly longer than that of the SCD strain, indicating a fitness cost of slower larval growth is associated with Ha_BtR disruption in H. armigera.