Expression of double-stranded RNAs in plastids offers great potential for the efficient control of chewing insects. However, many insect pests do not consume plant tissue but rather feed on the host plant by sucking sap from the vascular system. Whether or not plastid-mediated RNA interference (RNAi) can be employed to control sap-sucking insects is unknown. Here, we show that five species of sap-sucking hemipteran insects acquire plastid RNA upon feeding on plants. We generated both nuclear transgenic and transplastomic tobacco plants expressing double-stranded RNAs targeting the MpDhc64C gene, a newly identified efficient target gene of RNAi whose silencing causes lethality to the green peach aphid Myzus persicae. In a whole-plant bioassay, transplastomic plants exhibited significant resistance to aphids, as evidenced by reduced insect survival, impaired fecundity, and decreased weight of survivors. The protective effect was comparable with that conferred by the best-performing nuclear transgenic plants. We found that the proportion of aphids on mature leaves of transplastomic plants was significantly lower compared with that of nuclear transgenic plants. When aphids were allowed to infest only the mature leaves, transplastomic plants grew significantly faster and were overall better protected from the pest compared with nuclear transgenic plants. When monitored by electrical-penetration-graph analyses and aphid avoidance response experiments, the insects displayed remarkable alterations in feeding behavior, which was different in nuclear transgenic and transplastomic plants, likely reflecting specific avoidance strategies to toxic RNA molecules. Taken together, our study demonstrates that plastid-mediated RNAi provides an efficient strategy for controlling at least some sap-sucking insect pests, even though there is most likely no or only very little chloroplast RNA in the sap.

双链RNA在质体中的表达为有效控制咀嚼昆虫提供了巨大的潜力。然而，许多害虫不消耗植物组织，而是通过从维管系统中吸取汁液以寄主植物为食。是否可以使用质体介导的 RNA 干扰 (RNAi) 来控制吸汁昆虫是未知的。在这里，我们展示了五种吸汁半翅目昆虫在以植物为食时获得质体 RNA。我们生成了表达靶向MpDhc64C基因的双链 RNA 的核转基因烟草植物和转质体烟草植物，这是一种新发现的有效 RNAi 靶基因，其沉默导致绿桃蚜虫 桃蚜致死. 在全植物生物测定中，转基因植物对蚜虫表现出显着的抗性，这可以通过昆虫存活率降低、繁殖力受损和幸存者体重减轻来证明。保护作用与表现最好的核转基因植物所赋予的保护作用相当。我们发现，与核转基因植物相比，转质体植物成熟叶片上蚜虫的比例显着降低。当蚜虫只允许侵染成熟的叶子时，与核转基因植物相比，转质体植物的生长速度明显更快，并且总体上更好地保护了免受害虫的侵害。当通过电穿透图分析和蚜虫回避反应实验进行监测时，昆虫在摄食行为方面表现出显着变化，这在核转基因和转质体植物中是不同的，可能反映了对有毒 RNA 分子的特定回避策略。总之，我们的研究表明，质体介导的 RNAi 提供了一种有效的策略来控制至少一些吸汁害虫，即使汁液中很可能没有或只有很少的叶绿体 RNA。