Cis-mediated down-regulation of a trypsin gene associated with Bt resistance in cotton bollworm.
Cis-mediated down-regulation of a trypsin gene associated with Bt resistance in cotton bollworm.
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顺式介导的与棉铃虫 Bt 抗性相关的胰蛋白酶基因的下调
DOI：
10.1038/srep07219
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发表时间：
2014-11-27
影响因子：
4.6
通讯作者：
Wu K
中科院分区：
文献类型：
--
作者：
Liu C;Xiao Y;Li X;Oppert B;Tabashnik BE;Wu K
从苏云金芽孢杆菌（Bt）中产生杀虫蛋白的转基因植物可用于害虫防治，但当害虫产生抗性时，其效力会降低。本文研究了棉铃虫LF5品系对Bt毒素Cry1Ac的抗性机制。该菌株对Cry1Ac原毒素的抗性为110倍，对Cry1Ac激活毒素的抗性为39倍。对5个胰蛋白酶基因的评估显示，其中一个胰蛋白酶基因（HaTryR）的转录减少了99%与耐药性相关。在易感幼虫中用RNA干扰沉默该基因增加了它们在含有Cry1Ac的饮食中的存活率。对杂交后代的生物测定表明，对Cry1Ac的抗性与HaTryR存在遗传连锁。我们鉴定了耐药菌株HaTryR启动子区的突变。在转染的昆虫细胞系中，与敏感启动子相比，抗性启动子驱动的转录较低，这意味着HaTryR转录的顺式介导的下调是抗性的一种机制。结果表明，H.棉铃虫通过降低胰蛋白酶的表达来适应Bt毒素Cry1Ac。由于胰蛋白酶激活原毒素是毒性的关键步骤，因此具有激活毒素而不是原毒素的转基因植物可能会增加Bt作物的耐久性。
Transgenic plants producing insecticidal proteins from the bacteriumBacillus thuringiensis(Bt) are useful for pest control, but their efficacy is reduced when pests evolve resistance. Here we examined the mechanism of resistance to Bt toxin Cry1Ac in the laboratory-selected LF5 strain of the cotton bollworm,Helicoverpa armigera. This strain had 110-fold resistance to Cry1Ac protoxin and 39-fold resistance to Cry1Ac activated toxin. Evaluation of five trypsin genes revealed 99% reduced transcription of one trypsin gene (HaTryR) was associated with resistance. Silencing of this gene with RNA interference in susceptible larvae increased their survival on diets containing Cry1Ac. Bioassays of progeny from crosses revealed that resistance to Cry1Ac was genetically linked withHaTryR. We identified mutations in the promoter region ofHaTryRin the resistant strain. In transfected insect cell lines, transcription was lower when driven by the resistant promoter compared with the susceptible promoter, implicatingcis-mediated down-regulation ofHaTryRtranscription as a mechanism of resistance. The results suggest thatH. armigeracan adapt to Bt toxin Cry1Ac by decreased expression of trypsin. Because trypsin activation of protoxin is a critical step in toxicity, transgenic plants with activated toxins rather than protoxins might increase the durability of Bt crops.
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影响因子：
3.7
作者：
Jurat-Fuentes JL;Karumbaiah L;Jakka SR;Ning C;Liu C;Wu K;Jackson J;Gould F;Blanco C;Portilla M;Perera O;Adang M
通讯作者：
Adang M
影响因子：
4.4
作者：
Sayyed, AH;Gatsi, R;Crickmore, N
通讯作者：
Crickmore, N
DOI：
10.1073/pnas.1102555108
发表时间：
2011-08-23
影响因子：
11.1
作者：
Tiewsiri, Kasorn;Wang, Ping
通讯作者：
Wang, Ping
影响因子：
2.8
作者：
Kranthi, KR;Dhawad, CS;Kranthi, S
通讯作者：
Kranthi, S
影响因子：
3.8
作者：
Li, HR;Oppert, B;Buschman, LL
通讯作者：
Buschman, LL