Transcriptomic insights into the effects of CytCo, a novel nematotoxic protein, on the pine wood nematode Bursaphelenchus xylophilus

Abstract

Abstract Background The pine wood nematode Bursaphelenchus xylophilus is a destructive pest of Pinus trees worldwide and lacks effective control measures. Screening for nematotoxic proteins has been undertaken to develop new strategies for nematode control. Results The results of the present study provided initial insights into the responses of B. xylophilus exposed to a nematotoxic cytolytic-like protein (CytCo) based on transcriptome profiling. A large set of differentially expressed genes (DEGs = 1265) was found to be related to nematode development, reproduction, metabolism, motion, and immune system. In response to the toxic protein, B. xylophilus upregulated DEGs encoding cuticle collagens, transporters, and cytochrome P450. In addition, many DEGs related to cell death, lipid metabolism, major sperm proteins, proteinases/peptidases, phosphatases, kinases, virulence factors, and transthyretin-like proteins were downregulated. Gene Ontology enrichment analysis showed that the CytCo treatment substantially affected DEGs involved in muscle contraction, lipid localization, and the mitogen-activated protein kinase cascade. The pathway richness of the Kyoto Encyclopedia of Genes and Genomes showed that the DEGs were concentrated in lysosomes and involved in fatty acid degradation. Weighted co-expression network analysis indicated that the hub genes affected by CytCo were associated with the nematode cuticular collagen. Conclusions These results showed that CytCo toxin interferes with gene expression to exert multiple nematotoxic effects, thereby providing insights into its potential use in pine wood nematode control.

Keywords

• Cyt δ-endotoxin
• Entomophthoromycotina
• Nematotoxicity
• Plant parasitic nematode
• Transcriptome profiling