Hafeez Muhammad, Li Xiaowei, Ullah Farman, Zhang Zhijun, Zhang Jinming, Huang Jun, Fernández-Grandon G Mandela, Khan Muhammad Musa, Siddiqui Junaid Ali, Chen Limin, Ren Xiao Yun, Zhou Shuxing, Lou Yonggen, Lu Yaobin
State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, Hangzhou, China.
State Key Laboratory of Rice Biology and Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China.
Front Physiol. 2022 May 9;13:884447. doi: 10.3389/fphys.2022.884447. eCollection 2022.
The fall armyworm (FAW), (J.E. Smith), is a pest of many important crops globally. Effective control is challenging, with the pest exhibiting resistance to different synthetic pesticides across various groups. However, the mechanisms employed by resistant insects for overexpression of relevant detoxification genes remain unclear. The activity of detoxification enzymes was investigated in this study. Additionally, using RNA interference (RNAi), a functional analysis was completed of two P450s genes in an indoxacarb resistant population of fall armyworms. Elevated resistance levels (resistance ratio = 31.37-fold) in indoxacarb-selected populations of FAW were observed after 14 generations. The qRT-PCR showed higher expression of two cytochrome P450 genes, and , in this selected population compared to the control population. RNAi was applied to knock down the P450 ds and ds genes in the FAW larvae. Droplet feeding of the dsRNAs ( and ) via an artificial diet significantly increased mortality rates in the indoxacarb treated population. A shorter larval developmental time of FAW was detected in all dsRNAs-fed larvae. Correspondingly, larval mass was reduced by dsRNAs in indoxacarb resistant populations of fall armyworm. Larval feeding assays demonstrate that dsRNAs targeting, specifically of and enzymes, could be a beneficial technique in the management of indoxacarb resistant populations. Further study on the potential use of dsRNA and its application should be conducted in efforts to counter the development of resistance in FAW against various insecticides in the field.
草地贪夜蛾（Spodoptera frugiperda (J.E. Smith)）是全球许多重要农作物的害虫。有效控制具有挑战性，该害虫对不同类别的合成农药均表现出抗性。然而，抗性昆虫过表达相关解毒基因所采用的机制仍不清楚。本研究调查了解毒酶的活性。此外，利用RNA干扰（RNAi）技术，对草地贪夜蛾茚虫威抗性种群中的两个细胞色素P450基因进行了功能分析。经过14代筛选后，草地贪夜蛾茚虫威选择种群的抗性水平升高（抗性倍数 = 31.37倍）。qRT-PCR结果显示，与对照种群相比，该选择种群中两个细胞色素P450基因CYP9A2和CYP9A3的表达更高。应用RNAi技术敲低草地贪夜蛾幼虫中的P450 ds和ds基因。通过人工饲料点滴饲喂dsRNAs（CYP9A2和CYP9A3）显著提高了茚虫威处理种群的死亡率。在所有饲喂dsRNAs的幼虫中均检测到草地贪夜蛾幼虫发育时间缩短。相应地，dsRNAs降低了草地贪夜蛾茚虫威抗性种群的幼虫体重。幼虫取食试验表明，靶向CYP9A2和CYP9A3酶的dsRNAs可能是管理茚虫威抗性种群的一种有益技术。应进一步研究dsRNA的潜在用途及其应用，以应对草地贪夜蛾在田间对各种杀虫剂产生抗性的问题。
