Double-strand RNAs targeting MaltRelish and MaltSpz reveals potential targets for pest management of Monochamus alternatus

Xu Chu; Meijiao Yang; Lu Yu; Hongyun Xie; Jinyan Liu; Songqing Wu; Feiping Zhang; Xia Hu

doi:10.1016/j.pestbp.2023.105495

Double-strand RNAs targeting MaltRelish and MaltSpz reveals potential targets for pest management of Monochamus alternatus

Pestic Biochem Physiol. 2023 Aug:194:105495. doi: 10.1016/j.pestbp.2023.105495. Epub 2023 Jun 14.

Authors

Xu Chu¹, Meijiao Yang¹, Lu Yu¹, Hongyun Xie², Jinyan Liu¹, Songqing Wu¹, Feiping Zhang³, Xia Hu⁴

Affiliations

¹ Forestry College, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Key Laboratory of Integrated Pest Management in Ecological Forests, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
² Forestry College, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
³ Forestry College, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Key Laboratory of Integrated Pest Management in Ecological Forests, Fujian Agriculture and Forestry University, Fuzhou 350002, China. Electronic address: fpzhang@fafu.edu.cn.
⁴ Forestry College, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Key Laboratory of Integrated Pest Management in Ecological Forests, Fujian Agriculture and Forestry University, Fuzhou 350002, China. Electronic address: lake-autumn@fafu.edu.cn.

PMID: 37532354
DOI: 10.1016/j.pestbp.2023.105495

Abstract

Overcoming the innate immunity of insects is a key process to improve the efficiency of biological control. Antimicrobial peptides (AMPs) are important effectors in insect innate immunity, usually mediating resistance to pathogenic microorganisms through Toll and IMD signaling pathways. This study investigated the effect of key genes on upstream immune recognition receptor (GNBP₃) and downstream effectors (AMPs) by RNAi technology. The transcriptome KEGG enrichment analysis and differential gene annotation results showed that the immune response genes MaltSpz and MaltRelish are important regulators of Toll and IMD signaling pathways, respectively. Both dsSpz and dsRelish could affect AMP gene expression and increase the expression of the immune recognition receptor MaltGNBP₃. Moreover, they significantly reduce the survival rate of Monochamus alternatus and promote hyphal growth after Beauveria bassiana infection. This helps to improve the biological control effect of B. bassiana, control the population of vector insects and cut off the transmission route of pine wood nematode. The combined MaltSpz and MaltRelish knockdown increased the infection rate of M. alternatus larvae from 20.69% to 83.93%, achieving the best efficiency in synergistic B. bassiana infection. Our results showed important roles of MaltRelish- and MaltSpz-mediated regulation of AMP genes function in insect entomopathogenic fungi tolerance and induced significant mortality in larvae. Based on this study, MaltSpz and MaltRelish could represent candidate gene targets for the biological control of M. alternatus by RNAi.

Keywords: Biological control; Entomopathogenic fungus; Monochamus alternatus; RNAi.

MeSH terms

Animals
Beauveria*
Coleoptera* / genetics
Gene Expression Profiling
Larva
Pest Control