Transcriptome Analysis of the Japanese Pine Sawyer Beetle, Monochamus alternatus, Infected with the Entomopathogenic Fungus Metarhizium anisopliae JEF-197

Abstract

The Japanese pine sawyer (JPS) beetle, Monochamus alternatus Hope (Coleoptera: Cerambycidae), damages pine trees and transmits the pine wilt nematode, Bursaphelenchus xylophilus Nickle. Chemical agents have been used to control JPS beetle, but due to various issues, efforts are being made to replace these chemical agents with entomopathogenic fungi. We investigated the expression of immune-related genes in JPS beetle in response to infection with JEF-197, a Metarhizium anisopliae isolate, using RNA-seq. RNA samples were obtained from JEF-197, JPS adults treated with JEF-197, and non-treated JPS adults on the 8th day after fungal treatment, and RNA-seq was performed using Illumina sequencing. JPS beetle transcriptome was assembled de novo and differentially expressed gene (DEG) analysis was performed. There were 719 and 1953 up- and downregulated unigenes upon JEF-197 infection, respectively. Upregulated contigs included genes involved in RNA transport, ribosome biogenesis in eukaryotes, spliceosome-related genes, and genes involved in immune-related signaling pathways such as the Toll and Imd pathways. Forty-two fungal DEGs related to energy and protein metabolism were upregulated, and genes involved in the stress response were also upregulated in the infected JPS beetles. Together, our results indicate that infection of JPS beetles by JEF-197 induces the expression of immune-related genes.

Phytochemicals as Biopesticides against the Pinewood Nematode Bursaphelenchus xylophilus: A Review on Essential Oils and Their Volatiles

“…Important breakthroughs have been achieved with the analysis of genes involved in development, reproduction, parasitism, and drug resistance [44][45][46][47]. In addition, the transcriptomic analysis of the effects of novel pesticides or biocontrol agents for the PWN or its insect vector may reveal new mechanisms of activity with higher nematicidal efficiency [48,49].…”

Early-Stage Defense Mechanism of the Cotton Aphid Aphis gossypii Against Infection With the Insect-Killing Fungus Beauveria bassiana JEF-544

“…Pathogens are recognized inside the insect body and activate signaling pathways such as Toll, immune deficiency (IMD), Jun N-terminal kinase (JNK), and prophenoloxidase (PPO), and the consequent immune response occurs through production of antimicrobial peptide (AMP) and the cellular immune response. In a previous study, genes of the immune-related Toll and IMD pathways were up-regulated during infection by the Japanese pine sawyer beetle, Monochamus alternatus , which was infected with the fungal pathogen M. anisopliae ( 38 ). Longhorned ticks in the early stages of M. anisopliae infection expend a large amount of energy in catabolic processes against the fungal attack ( 39 ).…”

Identification of 35 C-Type Lectins in the Oriental Armyworm, Mythimna separata (Walker)

“…These data suggest that IMLs are important for immune responses in these stages. In the Japanese pine sawyer beetle, Monochamus alternatus infected with the entomopathogenic fungus Metarhizium anisopliae , several differentially expressed unigenes were CTLs [ 51 ]. Twelve CTL genes were identified in Adelphocoris suturalis (Hemiptera: Miridae) immune responsive genes against fungal and bacterial pathogens [ 52 ].…”