The cotton bollworm, Helicoverpa armigera , is a major insect pest for a wide range of agricultural crops. It causes significant yield loss through feeding damage and by increasing the crop’s vulnerability to bacterial and fungal infections. Although expression of Bacillus thuringiensis (Bt) toxins in transgenic crops has been very successful in protecting against insect pests, including H. armigera , field‐evolved resistance has occurred in multiple species. To manage resistant populations, new protection strategies must be continuously developed. Trans‐kingdom RNA interference (TK‐RNAi) is a promising method for controlling herbivorous pests. TK‐RNAi is based on delivering dsRNA or hairpin RNA containing essential insect gene sequences to the feeding insect. The ingested molecules are processed by the insect’s RNAi machinery and guide it to silence the target genes. Recently, TK‐RNAi delivery has been enhanced by expressing the ds‐ or hpRNAs in the chloroplast. This compartmentalizes the duplexed RNA away from the plant’s RNAi machinery, ensuring that it is delivered in an unprocessed form to the insect. Here, we report another alternative approach for delivering precursor anti‐insect RNA in plants. Insect pre‐microRNA (pre‐miR) transcripts were modified to contain artificial microRNAs (amiRs), targeting insect genes, and expressed in transgenic Nicotiana benthamiana plants. These modified pre‐miRs remained largely unprocessed in the plants, and H. armigera feeding on leaves from these plants had increased mortality, developmental abnormalities and delayed growth rates. This shows that plant‐expressed insect pre‐amiRs (plin‐amiRs) are a new strategy of protecting plants against herbivorous insects.

中文翻译：

---

Plin-amiR，一种基于前 microRNA 的技术，用于控制草食性害虫。


棉铃虫Helicoverpa armigera是多种农作物的主要害虫。它通过喂养损害和增加作物对细菌和真菌感染的脆弱性而导致严重的产量损失。尽管在转基因作物中表达苏云金芽孢杆菌(Bt) 毒素在预防包括棉铃虫在内的害虫方面非常成功，但多个物种中都出现了田间进化的抗性。为了管理耐药种群，必须不断制定新的保护策略。跨界RNA干扰（TK-RNAi）是控制草食性害虫的一种有前途的方法。 TK-RNAi 的基础是将含有昆虫必需基因序列的 dsRNA 或发夹 RNA 传递给摄食昆虫。摄入的分子由昆虫的 RNAi 机器处理并引导其沉默目标基因。最近，通过在叶绿体中表达 ds- 或 hpRNA 增强了 TK-RNAi 的传递。这将双链 RNA 与植物的 RNAi 机器分开，确保它以未加工的形式传递给昆虫。在这里，我们报告了另一种在植物中传递前体抗昆虫 RNA 的替代方法。昆虫前 microRNA (pre-miR) 转录物经过修饰，含有针对昆虫基因的人工 microRNA (amiR)，并在转基因本塞姆氏烟草植物中表达。这些经过修饰的 pre-miR 在植物中基本上未被加工，以这些植物的叶子为食的棉铃虫会增加死亡率、发育异常和生长速度延迟。 这表明植物表达的昆虫前amiRs（plin-amiRs）是保护植物免受草食性昆虫侵害的新策略。