瑞士伯尔尼大学Ricardo A. R. Machado团队发现，线虫的工程细菌共生体提高了西部玉米根虫（WCR）的生物防治潜能。这一研究成果2020年2月17日在线发表在国际学术期刊《自然—生物技术》上。

研究人员利用实验进化和选择对苯并嗪类化合物具有抗性的细菌共生体的方法，提高了线虫-共生体对WCR幼虫的杀伤能力。研究人员从不同的线虫中分离出五种光梭菌共生体，并通过实验进化提高了它们对苯并嗪类的抗性。苯并恶嗪类抗性通过多种机制进化获得，包括类水通道蛋白通道基因aqpZ的突变。研究人员将耐苯并嗪酮类的光杆状菌菌株重新引入其原昆虫病原线虫（EPN）宿主中，并鉴定出一对线虫-共生体对，它们能够更有效地杀死与苯并嗪酮类螯合的WCR幼虫。 该研究表明，细菌共生体的修饰可能为改善农业害虫生物防治提供普遍的策略。

据了解，西部玉米根虫（WCR）对全世界的玉米作物产生破坏性。用昆虫病原线虫（EPN）处理是控制这种害虫的一种潜在方法，该病原线虫具有对昆虫致病的细菌共生体。但是，螯合的WCR幼虫可利用玉米产生的苯并恶嗪类次生代谢物来增强其对线虫及其共生体的抗性。

附：英文原文

Title: Engineering bacterial symbionts of nematodes improves biocontrol potential of the western corn rootworm

Author: Ricardo A. R. Machado, Lisa Thnen, Carla C. M. Arce, Vanitha Theepan, Fausto Prada, Daniel Wthrich, Christelle A. M. Robert, Evangelia Vogiatzaki, Yi-Ming Shi, Olivier P. Schaeren, Matheus Notter, Rmy Bruggmann, Siegfried Hapfelmeier, Helge B. Bode, Matthias Erb

Issue&Volume: 2020-02-17

Abstract: The western corn rootworm (WCR) decimates maize crops worldwide. One potential way to control this pest is treatment with entomopathogenic nematodes (EPNs) that harbor bacterial symbionts that are pathogenic to insects. However, WCR larvae sequester benzoxazinoid secondary metabolites that are produced by maize and use them to increase their resistance to the nematodes and their symbionts. Here we report that experimental evolution and selection for bacterial symbionts that are resistant to benzoxazinoids improve the ability of a nematode–symbiont pair to kill WCR larvae. We isolated five Photorhabdus symbionts from different nematodes and increased their benzoxazinoid resistance through experimental evolution. Benzoxazinoid resistance evolved through multiple mechanisms, including a mutation in the aquaporin-like channel gene aqpZ. We reintroduced benzoxazinoid-resistant Photorhabdus strains into their original EPN hosts and identified one nematode–symbiont pair that was able to kill benzoxazinoid-sequestering WCR larvae more efficiently. Our results suggest that modification of bacterial symbionts might provide a generalizable strategy to improve biocontrol of agricultural pests.

DOI: 10.1038/s41587-020-0419-1

Source: https://www.nature.com/articles/s41587-020-0419-1