Host-induced gene silencing (HIGS) of insect growth and development is a promising measure for pest control in practice; the feasibility of disarming insect detoxification of toxic phytochemicals via HIGS of insect detoxification enzymes remains largely unexplored. In this study, a HIGS system was applied to interfere with glutathione S-transferase (GST) gene expression in brown planthopper (BPH, Nilaparvata lugens), a key insect pest in rice of Asia, and regulate rice resistance to the insect. The recombination vector in transgenic plants was expressed in almost all organs, especially in vascular bundle tissues, mesophyll, epidermal cells and leaf sheath sap, but not in xylem. Target BPH NlGST1-1 was successfully integrated into rice genome, the resultant transgenic rice lines harbored a single-copy of BPH NlGST1-1 dsRNA, and expression of NlGST1-1 dsRNA was detected in leaves and leaf sheaths of transgenic lines. However, the content of phytochemical gramine, an inherent alkaloid in gramineous plants, did not change in these transgenic plants. BPH nymphs reared on the transgenic rice expressing NlGST1-1 dsRNA displayed significant reductions in NlGST1-1 transcript expression and GST activity. The transgenic plants significantly retarded relative growth rate of the nymphs and the insect female fecundity, the plants also showed enhanced resistance when attacked by BPH. Our study demonstrated the feasibility of reinforcing gramine-mediated plant defense via HIGS of GSTs in herbivorous insects. HIGS-mediated suppression of the herbivore adaptive mechanism has significant implications for efficiently managing BPH and other pests in rice.

昆虫生长发育的宿主诱导基因沉默（HIGS）是实践中有害生物控制的一种有前途的措施。通过昆虫解毒酶的HIGS消除昆虫对有毒植物化学物质的解毒的可行性仍未得到充分的探讨。在这项研究中，HIGS系统被应用于干扰亚洲稻米的主要害虫褐飞虱（BPH，Nilaparvata lugens）中的谷胱甘肽S-转移酶（GST）基因表达，并调节水稻对这种昆虫的抗性。转基因植物中的重组载体在几乎所有器官中都有表达，尤其是在维管束组织，叶肉，表皮细胞和叶鞘汁液中表达，而在木质部中则没有。目标BPH NlGST1 - 1被成功地整合到水稻基因组中，所得到的转基因水稻品系窝藏BPH的单拷贝NlGST1 - 1的dsRNA，和表达的NlGST1 - 1的dsRNA在叶子和转基因品系叶鞘进行检测。然而，在这些转基因植物中，植物化学禾胺的含量没有变化，禾本科植物中固有的生物碱。饲养转基因水稻褐飞虱表达若虫NlGST1 - 1的dsRNA在显示显著减少NlGST1 - 1转录表达和GST活性。转基因植物显着阻碍了若虫的相对生长速度和昆虫雌性繁殖力，当受到BPH攻击时，这些植物还显示出增强的抗性。我们的研究证明了在草食性昆虫中通过GST的HIGS增强草胺介导的植物防御的可行性。HIGS介导的对草食动物适应机制的抑制对于有效管理水稻中的BPH和其他害虫具有重要意义。