Whitten Miranda M A, Xue Qi, Taning Clauvis Nji Tizi, James Reuben, Smagghe Guy, Del Sol Ricardo, Hitchings Matthew, Dyson Paul
Institute of Life Science, Swansea University Medical School, Singleton Park, Swansea, United Kingdom.
Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium.
Front Insect Sci. 2023 Mar 8;3:1093970. doi: 10.3389/finsc.2023.1093970. eCollection 2023.
Insecticidal RNAi is a targeted pest insect population control measure. The specificity of insecticidal RNAi can theoretically be enhanced by using symbiotic bacteria with a narrow host range to deliver RNAi, an approach termed symbiont-mediated RNAi (SMR), a technology we have previously demonstrated in the globally-invasive pest species Western Flower Thrips (WFT).
Here we examine distribution of the two predominant bacterial symbionts of WFT, BFo1 and BFo2, among genome-sequenced insects. Moreover, we have challenged two non-target insect species with both bacterial species, namely the pollinating European bumblebee, Bombus terrestris, and an insect predator of WFT, the pirate bug Orius laevigatus.
Our data indicate a very limited distribution of either symbiont among insects other than WFT. Moreover, whereas BFo1 could establish itself in both bees and pirate bugs, albeit with no significant effects on insect fitness, BFo2 was unable to persist in either species.
In terms of biosafety, these data, together with its more specific growth requirements, vindicate the choice of BFo2 for delivery of RNAi and precision pest management of WFT.
杀虫RNA干扰是一种针对害虫种群的控制措施。理论上，通过使用宿主范围狭窄的共生细菌来传递RNA干扰，可以提高杀虫RNA干扰的特异性，这种方法称为共生菌介导的RNA干扰（SMR），我们之前已在全球入侵性害虫西花蓟马（WFT）中证明了这项技术。
在此，我们研究了西花蓟马的两种主要细菌共生菌BFo1和BFo2在已进行基因组测序的昆虫中的分布情况。此外，我们用这两种细菌分别对两种非靶标昆虫进行了试验，即传粉昆虫欧洲熊蜂（Bombus terrestris）和西花蓟马的捕食性昆虫猎蝽（Orius laevigatus）。
我们的数据表明，除西花蓟马外，这两种共生菌在其他昆虫中的分布非常有限。此外，虽然BFo1能够在蜜蜂和猎蝽体内定殖，尽管对昆虫的适应性没有显著影响，但BFo2无法在这两种昆虫中持续存在。
在生物安全性方面，这些数据及其更特殊的生长要求，证明了选择BFo2用于传递RNA干扰以及对西花蓟马进行精准害虫管理的合理性。
