Abstract：
RNA interference (RNAi) is recognized as a new and environmentally friendly pest control strategy due to its high specificity. However, the RNAi efficiency is relatively low in many sucking insect pests, such as Apolygus lucorum. Therefore, there is an urgent need to develop new and effective ways of dsRNA delivery. Bacterially expressed or T7 synthesized dsRNA targeting a G Protein-Coupled Receptor Kinase 2 gene was mixed with chitosan in a 1:2 ratio by mass. The size of the chitosan/dsRNA nanoparticles was 69 ± 12 nm, and the TEM and AFM images showed typical spherical or ellipsoidal structures. The chitosan nanoparticles protected the dsRNA from nuclease activity, and pH and temperature-dependent degradation, and the fluorescently-tagged nanoparticles were found to be stable on the surface of green bean plants (48 h) (Phaseolus vulgaris) and were absorbed by midgut epithelial cells and transported to hemolymph. Once fed to the A. lucorum nymph, chitosan/dsRNA could effectively inhibit the expression of the G protein-coupled receptor kinase 2 gene (70%), and led to significantly increase mortality (50%), reduced weight (26.54%) and a prolonged developmental period (8.04%). The feeding-based and chitosan-mediated dsRNA delivery method could be a new strategy for A. lucorum management, providing an effective tool for gene silencing of piercing-sucking insects.
摘要：
RNA干扰（RNAi）由于其高特异性而被认为是一种新型的环境友好型害虫控制策略。然而,在许多吸吮害虫中，RNAi效率相对较低，比如Ayarguslucorum.因此,迫切需要开发新的有效的dsRNA递送方式。将细菌表达的或T7合成的靶向G蛋白偶联受体激酶2基因的dsRNA与壳聚糖以1:2的质量比混合。壳聚糖/dsRNA纳米粒的大小为69±12nm,TEM和AFM图像显示典型的球形或椭圆形结构。壳聚糖纳米颗粒保护dsRNA免受核酸酶活性，和pH和温度依赖性降解，发现荧光标记的纳米颗粒在绿豆植物（48h）（菜豆）表面稳定，并被中肠上皮细胞吸收并转运至血淋巴。一旦喂给A.lucorum若虫，壳聚糖/dsRNA能有效抑制G蛋白偶联受体激酶2基因(70%)的表达,并导致死亡率显着增加（50％），体重减轻（26.54％）和发育期延长（8.04％）。基于饲喂和壳聚糖介导的dsRNA递送方法可能是A.lucorum管理的新策略，为刺吸昆虫的基因沉默提供了有效的工具。
