Ge Panpan, Lu Xiangyang, Zhao Wan, Wu Shaohui, Smith Neil, Gao Ling-Ling, Guo Hui-Shan, Wang Ming-Bo, Cui Feng
State Key Laboratory of Animal Biodiversity Conservation and Integrated Pest Management, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
College of Plant Protection, Shandong Agricultural University, Taian, Shandong Province, China.
Insect Sci. 2025 Jul 14. doi: 10.1111/1744-7917.70128.
RNA interference, induced by double-stranded RNA (dsRNA), has emerged as a biopesticide for pest control. However, the stability of dsRNA remains a challenge in topical delivery, preventing widespread agricultural application. Here, we tested a dsRNA variant, called loop-ended dsRNA or LedRNA, for controlling a notorious vector insect, the small brown planthopper (SBPH). LedRNA is characterized by having a loop at both ends of the dsRNA stem, resembling a close-circled RNA. Three SBPH target genes, including Flotillin2, which is vital for viral transmission, and trehalose-6-phosphate synthase (TPS) and malate dehydrogenases (MDH), which are essential for insect survival, were tested for gene silencing efficiencies through microinjection, soaking, or oral delivery of the conventional dsRNA, hairpin dsRNA, and LedRNA. All 3 molecules induced effective gene silencing using microinjection, but did not suppress target gene expression through soaking. Notably, LedRNA demonstrated superior efficacy in inducing gene silencing in SBPH through oral feeding compared to the other 2 molecules. Silencing efficiencies ranged from 26% to 39% for Flotillin2, 39% to 51% for TPS, and 45% to 64% for MDH. When SBPH were fed Escherichia coli-synthesized LedRNA targeting these 3 genes, silencing efficiencies ultimately reached 28% to 74%, leading to reduced insect survival and decreased viral transmission in host plant rice. This study highlights the potential of LedRNA as a biopesticide for insect pest control.
由双链RNA（dsRNA）诱导的RNA干扰已成为一种用于害虫防治的生物农药。然而，dsRNA的稳定性在局部递送中仍然是一个挑战，阻碍了其在农业中的广泛应用。在此，我们测试了一种dsRNA变体，称为环端dsRNA或LedRNA，用于控制一种臭名昭著的媒介昆虫——褐飞虱（SBPH）。LedRNA的特征是在dsRNA茎的两端都有一个环，类似于一个闭环RNA。通过显微注射、浸泡或口服递送常规dsRNA、发夹dsRNA和LedRNA，测试了三个SBPH靶基因的基因沉默效率，其中包括对病毒传播至关重要的Flotillin2，以及对昆虫生存必不可少的海藻糖-6-磷酸合酶（TPS）和苹果酸脱氢酶（MDH）。所有这三种分子通过显微注射都能诱导有效的基因沉默，但通过浸泡不能抑制靶基因表达。值得注意的是，与其他两种分子相比，LedRNA通过口服喂食在诱导SBPH基因沉默方面表现出更高的效率。Flotillin2的沉默效率为26%至39%，TPS为39%至51%，MDH为45%至64%。当给SBPH喂食大肠杆菌合成的靶向这三个基因的LedRNA时，沉默效率最终达到28%至74%，导致昆虫存活率降低，宿主植物水稻中的病毒传播减少。这项研究突出了LedRNA作为一种用于害虫防治的生物农药的潜力。
