Promoting Effect of Choline-Phosphate Cytidylyltransferase Gene (pcyt-1) on Departure of Pinewood Nematode from Monochamus alternatus

Mingxia Jin,Yang Wang,Fengmao Chen,Lichao Wang,Guai Xie,Ailin Yu

doi:10.3390/f13010114

Mingxia Jin, Yang Wang + Show 4 more

Open Access

https://doi.org/10.3390/f13010114

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Journal: Forests	Publication Date: Jan 13, 2022
Citations: 2	License type: CC BY 4.0

Affiliation: Nanjing Forestry University, Jiangxi Academy of Forestry

Abstract

In order to study the key gene in internal causes of pinewood nematode (PWN), Bursaphelenchus xylophilus, a departure from its vector beetle, Monochamus alternatus, we collected PWNs extracted from newly emerged M. alternatus and beetles 7 days after emergence. The total RNAs of the two groups of PWNs were extracted, transcriptomes sequencing was performed, and gene expression differences between the two groups of PWN were analyzed. It was found that the expression of the choline-phosphate cytidylyltransferase gene (pcyt-1) was markedly up-regulated. After inhibition of pcyt-1 expression by RNA interference, the rate of lipid degradation in PWN decreased significantly, and the motility of PWN also decreased significantly. The analysis identified that phosphatidylcholine could promote the emulsification and degradation of neutral lipid granules in PWN, which provides sufficient energy for PWN departure from M. alternatus. The up-regulation of the gene pcyt-1 is an important internal factor for PWN departure from its vector.

Highlights

Academic Editors: Salvatore MoriccaPine wilt disease (PWD) constitutes one of the most serious conifer diseases worldwide, affecting Pinus spp. from the Far East forestlands (Japan, China, Korea) [1,2], and to Europe (Portugal and Spain) and North America [3,4,5,6,7]
PWD is caused by the pinewood nematode (PWN), Bursaphelenchus xylophilus (Steiner & Buhrer) Nickle, with PWN transmission being dependent on a vector insect, such as Monochamus alternatus Hope, the main vector in East
It was suggested that PWN departure is related to the motility but not associated volatiles and that increased motility required energy, which mainly comes from the degradation of neutral lipids [21,28]

Summary

Introduction

Pine wilt disease (PWD) constitutes one of the most serious conifer diseases worldwide, affecting Pinus spp. from the Far East forestlands (Japan, China, Korea) [1,2], and to Europe (Portugal and Spain) and North America [3,4,5,6,7]. The feeding period of adult M. alternatus is an important stage in the life cycle of the beetles as well as a key step in PWN transmission [10,11]. Enda et al dried Pinus twigs at 70 ◦ C to remove volatile substances, treated twigs with β-myrcene and fed them to the beetles, these twigs greatly promoted the departure of PWN from M. alternatus [25]. Previous studies showed that intrinsic factors play an important role in regulating PWN departure, whereas β-myrcene is a directional signal that promotes PWN escape from vector insects [26]. It was suggested that PWN departure is related to the motility but not associated volatiles and that increased motility required energy, which mainly comes from the degradation of neutral lipids [21,28]. Important genes related to lipid emulsification metabolism were screened, RNA interference (RNAi) was carried out, and the effect on lipid degradation and PWN motility was determined

PWN Collection and RNA Extraction

Collection

RNA Quantification and Qualification

Comparative Analysis and Gene Functional Annotation

Differential Expression Analysis

Pathway Enrichment Analysis

Comparison of Transcriptome Results

Motility and Lipid Content of PWN

Discussion