Plant Biotechnol J:中科院遗传所朱祯研究组等发表植物RNAi抗虫研究
2017年3月16日，国际期刊《Plant Biotechnology Journal》在线发表了中国科学院遗传与发育生物学研究所朱祯研究组、南京农业大学农学院张天真教授研究组和亚利桑那大学昆虫系教授Bruce E. Tabashnik研究组共同合作的研究论文，研究在植物RNAi抗虫研究中取得进展。倪密、马卫、王晓芳、高美静等为共同第一作者，朱祯研究员、张天真教授和Bruce E. Tabashnik教授为文章通讯作者。
植物寄主介导的rnai技术，对于植物鞘翅目和鳞翅目害虫的防治具有巨大的潜力。利用寄主植物表达靶基因dsRNA，高量表达的dsRNA能够被植食性昆虫摄入体内，然后诱发系统RNAi反应，进而成功干扰目标昆虫靶基因的表达达到杀虫目的。挖掘理想的RNAi靶标基因并将其应用于植物抗虫育种是当前的关键问题。
朱祯研究组通过大量RNAi靶标的筛选，最终确定控制昆虫保幼激素代谢的关键基因为最佳靶标，培育了可表达阻断棉铃虫激素合成dsRNA的转基因棉花，该转基因棉表现出很强的抗虫性，尤其对于Bt耐受性棉铃虫系有很好防治效果。分子检测结果表明，转基因棉花成功表达了高量dsRNA，受试昆虫体内靶基因表达明显下调，保幼激素本身合成被显著抑制。聚合上述RNAi和Bt的转基因棉花抗虫效果进一步增强。此外，分析多年抗虫生测数据表明，RNAi抗虫棉可明显延缓棉铃虫抗性的产生。以昆虫保幼激素RNAi抗虫棉及RNAi + Bt的聚合棉可以克服棉铃虫对单一策略转基因棉易产生耐受性的难题，同时为下一代抗虫作物的研发奠定了基础。
原文链接：
Next-generation transgenic cotton: pyramiding RNAi and Bt counters insect resistance
原文摘要：
Transgenic crops producing insecticidal proteins from the bacterium Bacillus thuringiensis (Bt) are extensively cultivated worldwide. To counter rapidly increasing pest resistance to crops that produce single Bt toxins, transgenic plant ‘pyramids’ producing two or more Bt toxins that kill the same pest have been widely adopted. However, cross-resistance and antagonism between Bt toxins limit the sustainability of this approach. Here we describe development and testing of the first pyramids of cotton combining protection from a Bt toxin and RNA interference (RNAi). We developed two types of transgenic cotton plants producing double-stranded RNA (dsRNA) from the global lepidopteran pest Helicoverpa armigera designed to interfere with its metabolism of juvenile hormone (JH). We focused on suppression of JH acid methyltransferase (JHAMT), which is crucial for JH synthesis, and JH-binding protein (JHBP), which transports JH to organs. In 2015 and 2016, we tested larvae from a Bt-resistant strain and a related susceptible strain of H. armigera on seven types of cotton: two controls, Bt cotton, two types of RNAi cotton (targeting JHAMT or JHBP) and two pyramids (Bt cotton plus each type of RNAi). Both types of RNAi cotton were effective against Bt-resistant insects. Bt cotton and RNAi acted independently against the susceptible strain. In computer simulations of conditions in northern China, where millions of farmers grow Bt cotton as well as abundant non-transgenic host plants of H. armigera, pyramided cotton combining a Bt toxin and RNAi substantially delayed resistance relative to using Bt cotton alone.
作者：朱祯
