RNA interference (RNAi) is a promising technology for the development of next‐generation insect pest control products. Though RNAi is efficient and systemic in coleopteran insects, it is inefficient and variable in lepidopteron insects. In this study, we explored the possibility of improving RNAi in the fall armyworm (FAW), Spodoptera frugiperda by conjugating double‐stranded RNA (dsRNA) with biodegradable chitosan (Chi). dsRNA conjugated with chitosan was protected from degradation by endonucleases present in Sf9 cell‐conditioned medium, hemolymph, and midgut lumen contents collected from the FAW larvae. Chi–dsRNA complexes showed reduced accumulation in the endosomes of Sf9 cells and FAW tissues. Exposing chitosan formulated dsRNA in Sf9 cells and the tissues induced a significant knockdown of endogenous genes. Chi–dsIAP fed to FAW larvae induced knockdown of iap gene, growth retardation, and mortality. Processing of dsRNA into small interfering RNA was detected with chitosan‐conjugated ³²P‐UTP‐labeled ds green fluorescent protein in Sf9 cells and FAW larval tissues. Overall, these data suggest that dsRNA conjugated with chitosan helps dsRNA escape from the endosomes and improves RNAi efficiency in FAW cells and tissues.

中文翻译：

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壳聚糖纳米颗粒帮助双链RNA从内体中逸出，并改善了秋天粘虫Spodoptera frugiperda中的RNA干扰。

RNA干扰（RNAi）是开发下一代病虫害防治产品的有前途的技术。尽管RNAi在鞘翅目昆虫中是有效的和内吸性的，但在鳞翅目昆虫中是无效的且可变的。在这项研究中，我们探讨了改善秋天粘虫（FAW），斜纹夜蛾（Spodoptera frugiperda）RNAi的可能性通过将双链RNA（dsRNA）与可生物降解的壳聚糖（Chi）结合。从一汽幼虫收集的Sf9细胞条件培养基，血淋巴和中肠腔内容物中存在的核酸内切酶可保护与壳聚糖偶联的dsRNA免受降解。Chi-dsRNA复合物在Sf9细胞和一汽组织的内体中显示出减少的积累。暴露于壳聚糖中的Sf9细胞和组织中的dsRNA诱导了显着的内源基因敲低。向一汽幼虫喂食的Chi–dsIAP诱导了iap基因的敲低，生长迟缓和死亡率。用壳聚糖偶联的³²检测到将dsRNA加工成小干扰RNAP-UTP标记的Sf9细胞和一汽幼虫组织中的ds绿色荧光蛋白。总体而言，这些数据表明与壳聚糖缀合的dsRNA有助于dsRNA从内体中逸出并提高一汽细胞和组织中RNAi的效率。