Cross-Resistance between Cry1 Proteins in Fall Armyworm (Spodoptera frugiperda) May Affect the Durability of Current Pyramided Bt Maize Hybrids in Brazil.
Cross-Resistance between Cry1 Proteins in Fall Armyworm (Spodoptera frugiperda) May Affect the Durability of Current Pyramided Bt Maize Hybrids in Brazil.
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DOI：
10.1371/journal.pone.0140130
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发表时间：
2015
期刊：
影响因子：
3.7
通讯作者：
Omoto C
中科院分区：
文献类型：
--
作者：
Bernardi D;Salmeron E;Horikoshi RJ;Bernardi O;Dourado PM;Carvalho RA;Martinelli S;Head GP;Omoto C
表达苏云金芽孢杆菌（Bt）杀虫蛋白的转基因植物为管理昆虫害虫提供了有价值的选择，具有相当大的环境和经济效益。尽管Bt作物提供了益处，但这些杀虫蛋白的连续表达对目标害虫种群的抗性施加了强选择。自2008年以来，Bt玉米（Zea mays）杂交种已成功控制了巴西主要的玉米害虫秋粘虫（Spodoptera frugiperda）;然而，最近有报道称，田间进化出了对Cry 1F蛋白质的抗性。因此，研究Bt玉米杂交种中Cry 1F与其他Cry蛋白的交叉抗性具有重要意义。在本研究中，采用F2筛选，随后在MON 89034玉米上进行选择以选择S。frugiperda菌株（RR）能够在表达Cry1A.105和Cry 2Ab 2蛋白的Bt玉米事件MON 89034上存活。从表达Cry 1F蛋白（事件TC 1507）的玉米田间收集的昆虫代表了发现的大多数阳性（含抗性等位基因）（iso）families. RR菌株显示出对Cry 1F的高水平抗性，这显然也赋予了对Cry 1A. 105和Cry 1Ab的高水平交叉抗性，但对Cry 2Ab 2仅具有低水平（10倍）抗性。生活史研究，调查健身成本与RR株的阻力显示，只有小的减少生殖率相比，敏感和杂合子株，但RR株产生的女性少32.2%和28.4%，从每个女性相对于SS和RS（合并）株，分别。与缺乏对Cry 2Ab 2的显著抗性一致，MON 89034玉米结合适当的管理措施继续提供对S. frugiperda在巴西尽管如此，在S. 105的交互抗性，表明目前基于Cry 1的玉米杂交种在管理S. frugiperda在巴西的研究，并强调了有效的昆虫抗性管理对这些技术的重要性。
Genetically modified plants expressing insecticidal proteins from Bacillus thuringiensis (Bt) offer valuable options for managing insect pests with considerable environmental and economic benefits. Despite the benefits provided by Bt crops, the continuous expression of these insecticidal proteins imposes strong selection for resistance in target pest populations. Bt maize (Zea mays) hybrids have been successful in controlling fall armyworm (Spodoptera frugiperda), the main maize pest in Brazil since 2008; however, field-evolved resistance to the protein Cry1F has recently been reported. Therefore it is important to assess the possibility of cross-resistance between Cry1F and other Cry proteins expressed in Bt maize hybrids. In this study, an F2 screen followed by subsequent selection on MON 89034 maize was used to select an S. frugiperda strain (RR) able to survive on the Bt maize event MON 89034, which expresses the Cry1A.105 and Cry2Ab2 proteins. Field-collected insects from maize expressing the Cry1F protein (event TC1507) represented most of the positive (resistance allele-containing) (iso)families found. The RR strain showed high levels of resistance to Cry1F, which apparently also conferred high levels of cross resistance to Cry1A.105 and Cry1Ab, but had only low-level (10-fold) resistance to Cry2Ab2. Life history studies to investigate fitness costs associated with the resistance in RR strain revealed only small reductions in reproductive rate when compared to susceptible and heterozygous strains, but the RR strain produced 32.2% and 28.4% fewer females from each female relative to the SS and RS (pooled) strains, respectively. Consistent with the lack of significant resistance to Cry2Ab2, MON 89034 maize in combination with appropriate management practices continues to provide effective control of S. frugiperda in Brazil. Nevertheless, the occurrence of Cry1F resistance in S. frugiperda across Brazil, and the cross-resistance to Cry1Ab and Cry1A.105, indicates that current Cry1-based maize hybrids face a challenge in managing S. frugiperda in Brazil and highlights the importance of effective insect resistance management for these technologies.