Bt Cry1Ab/2Ab toxins disrupt the structure of the gut bacterial community of Locusta migratoria through host immune responses

Yue Yin; Kaili Cao; Xinxin Zhao; Chuan Cao; Xuehui Dong; Jingang Liang; Wangpeng Shi

doi:10.1016/j.ecoenv.2022.113602

Bt Cry1Ab/2Ab toxins disrupt the structure of the gut bacterial community of Locusta migratoria through host immune responses

Ecotoxicol Environ Saf. 2022 Jun 15:238:113602. doi: 10.1016/j.ecoenv.2022.113602. Epub 2022 May 5.

Authors

Yue Yin¹, Kaili Cao², Xinxin Zhao³, Chuan Cao⁴, Xuehui Dong⁵, Jingang Liang⁶, Wangpeng Shi⁷

Affiliations

¹ Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, China Agricultural University, Beijing 100094, China. Electronic address: 15851075264@163.com.
² Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, China Agricultural University, Beijing 100094, China. Electronic address: caokailixjnu@163.com.
³ Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, China Agricultural University, Beijing 100094, China. Electronic address: 2016319010215@cau.edu.cn.
⁴ Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, China Agricultural University, Beijing 100094, China. Electronic address: chuancao@cau.edu.cn.
⁵ Department of Agriculture Science, China Agricultural University, Beijing 100094, China. Electronic address: xuehuidong@cau.edu.cn.
⁶ Development Center of Science and Technology, Ministry of Agriculture and Rural Affairs, Beijing 100176, China. Electronic address: liangjingang@agri.gov.cn.
⁷ Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, China Agricultural University, Beijing 100094, China. Electronic address: wpshi@cau.edu.cn.

PMID: 35526455
DOI: 10.1016/j.ecoenv.2022.113602

Abstract

The gut microbiota of insects plays a vital role in digestion, nutrient acquisition, metabolism of dietary toxins, pathogen immunity and maintenance of gut homeostasis. Bacillus thuringinensis (Bt) poisons target insects through its toxins that are activated in the insect gut. The effects of Bt toxins on gut microbiota of insects and their underlying mechanisms are not well understood. In this study, we found that Cry1Ab/2Ab toxins significantly changed the gut bacterial community's structure and reduced the total load of gut bacteria in the Locusta migratoria. In addition, Cry toxins significantly increased the level of reactive oxygen species (ROS) in the gut of locusts. Our results also showed that Cry1Ab/2Ab toxins induced the host gut's immune response by up-regulating of key genes in the Immune deficiency (IMD) and Toll pathway. RNA interference showed that knocking down Relish could narrow the difference in the load, diversity, and composition in gut bacteria caused by Cry toxins. Our findings suggest that Bt potentially influences the gut bacterial community of L. migratoria through host immune response.

Keywords: Bacillus thuringinensis; Cry toxins; Gut bacteria; Immune response; Locusta migratoria.

MeSH terms

Animals
Bacillus thuringiensis* / genetics
Bacillus*
Bacterial Proteins / genetics
Bacterial Proteins / toxicity
Endotoxins / toxicity
Gastrointestinal Microbiome*
Hemolysin Proteins / genetics
Hemolysin Proteins / toxicity
Immunity
Insecta
Locusta migratoria*
Neoptera

Substances

Bacterial Proteins
Endotoxins
Hemolysin Proteins