Enhanced resistance to Bacillus thuringiensis Cry1Ac toxin mediated by the activation of prophenoloxidase in a cosmopolitan pest

Zeyun Li; Lei Xiong; Jingge Li; Shuyuan Yao; Yi Dong; Yongbin Li; Xuanhao Chen; Min Ye; Yangrui Zhang; Xuefeng Xie; Minsheng You; Zhiguang Yuchi; Yuanyuan Liu; Shijun You

doi:10.1016/j.ijbiomac.2023.124678

Enhanced resistance to Bacillus thuringiensis Cry1Ac toxin mediated by the activation of prophenoloxidase in a cosmopolitan pest

Int J Biol Macromol. 2023 Jul 1;242(Pt 1):124678. doi: 10.1016/j.ijbiomac.2023.124678. Epub 2023 May 2.

Authors

Zeyun Li¹, Lei Xiong¹, Jingge Li¹, Shuyuan Yao¹, Yi Dong¹, Yongbin Li¹, Xuanhao Chen¹, Min Ye¹, Yangrui Zhang², Xuefeng Xie³, Minsheng You⁴, Zhiguang Yuchi⁵, Yuanyuan Liu⁶, Shijun You⁷

Affiliations

¹ State Key Laboratory of Crop Pest Control in Fujian and Taiwan, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China; International Joint Research Laboratory of Ecological Pest Control, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Key Laboratory of Integrated Pest Management for Fujian-Taiwan Crops, Ministry of Agriculture and Rural Affairs, Fuzhou 350002, China; Key Laboratory of Green Control of Insect Pests, Fujian Province University, Fuzhou 350002, China.
² BGI-Sanya, BGI-Shenzhen, Sanya 572025, China. Electronic address: zhangyangrui@genomics.cn.
³ BGI-Sanya, BGI-Shenzhen, Sanya 572025, China. Electronic address: xiexuefeng@genomics.cn.
⁴ State Key Laboratory of Crop Pest Control in Fujian and Taiwan, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China; International Joint Research Laboratory of Ecological Pest Control, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Key Laboratory of Integrated Pest Management for Fujian-Taiwan Crops, Ministry of Agriculture and Rural Affairs, Fuzhou 350002, China; Key Laboratory of Green Control of Insect Pests, Fujian Province University, Fuzhou 350002, China. Electronic address: msyou@fafu.edu.cn.
⁵ School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 300072, China. Electronic address: yuchi@tju.edu.cn.
⁶ State Key Laboratory of Crop Pest Control in Fujian and Taiwan, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China; BGI-Sanya, BGI-Shenzhen, Sanya 572025, China; Basic Forestry and Proteomics Center, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou 350002, China. Electronic address: yyliu@fafu.edu.cn.
⁷ State Key Laboratory of Crop Pest Control in Fujian and Taiwan, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China; International Joint Research Laboratory of Ecological Pest Control, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Key Laboratory of Integrated Pest Management for Fujian-Taiwan Crops, Ministry of Agriculture and Rural Affairs, Fuzhou 350002, China; Key Laboratory of Green Control of Insect Pests, Fujian Province University, Fuzhou 350002, China; BGI-Sanya, BGI-Shenzhen, Sanya 572025, China. Electronic address: sjyou@fafu.edu.cn.

PMID: 37141972
DOI: 10.1016/j.ijbiomac.2023.124678

Abstract

Plutella xylostella has evolved resistance to Bacillus thuringiensis Cry1Ac toxin over a long evolutionary period. Enhanced immune response is an important factor in insect resistance to a variety of insecticides, and whether phenoloxidase (PO), an immune protein, is involved in resistance to Cry1Ac toxin in P. xylostella remains unclear. Here, spatial and temporal expression patterns showed that prophenoloxidase (PxPPO1 and PxPPO2) in the Cry1S1000-resistant strain was more highly expressed in eggs, 4th instar, head, and hemolymph than those in G88-susceptible strain. The results of PO activity analysis showed that after treatment with Cry1Ac toxin PO activity was about 3 times higher than that before treatment. Furthermore, knockout of PxPPO1 and PxPPO2 significantly increased the susceptibility to Cry1Ac toxin. These findings were further supported by the knockdown of Clip-SPH2, a negative regulator of PO, which resulted in increased PxPPO1 and PxPPO2 expression and Cry1Ac susceptibility in the Cry1S1000-resistant strain. Finally, the synergistic effect of quercetin showed that larval survival decreased from 100 % to <20 % compared to the control group. This study will provide a theoretical basis for the analysis of immune-related genes (PO) genes involved in the resistance mechanism and pest control of P. xylostella.

Keywords: Cry1Ac resistance; Plutella xylostella; Prophenoloxidase.

MeSH terms

Animals
Bacillus thuringiensis Toxins / metabolism
Bacillus thuringiensis* / genetics
Bacterial Proteins / metabolism
Endotoxins / metabolism
Hemolysin Proteins / genetics
Hemolysin Proteins / metabolism
Hemolysin Proteins / pharmacology
Larva
Monophenol Monooxygenase / metabolism
Moths* / metabolism

Substances

pro-phenoloxidase
Endotoxins
Bacillus thuringiensis Toxins
Monophenol Monooxygenase
Hemolysin Proteins
Bacterial Proteins