Influence of Bxpel1 Gene Silencing by dsRNA Interference on the Development and Pathogenicity of the Pine Wood Nematode, Bursaphelenchus xylophilus.

Xiu-Wen Qiu,Lin Huang,Jian-Ren Ye,Xiao-Qin Wu

doi:10.3390/ijms17010125

Xiu-Wen Qiu, Lin Huang + Show 2 more

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https://doi.org/10.3390/ijms17010125

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Abstract

As the causal agent of pine wilt disease (PWD), the pine wood nematode (PWN), Bursaphelenchus xylophilus, causes huge economic losses by devastating pine forests worldwide. The pectate lyase gene is essential for successful invasion of their host plants by plant-parasitic nematodes. To demonstrate the role of pectate lyase gene in the PWD process, RNA interference (RNAi) is used to analyze the function of the pectate lyase 1 gene in B. xylophilus (Bxpel1). The efficiency of RNAi was detected by real-time PCR. The result demonstrated that the quantity of B. xylophilus propagated with control solution treatment was 62 times greater than that soaking in double-stranded RNA (dsRNA) after B. xylophilus inoculation in Botrytis cinerea for the first generation (F1). The number of B. xylophilus soaking in control solution was doubled compared to that soaking in Bxpel1 dsRNA four days after inoculation in Pinus thunbergii. The quantity of B. xylophilus was reduced significantly (p < 0.001) after treatment with dsRNAi compared with that using a control solution treatment. Bxpel1 dsRNAi reduced the migration speed and reproduction of B. xylophilus in pine trees. The pathogenicity to P. thunbergii seedling of B. xylophilus was weaker after soaking in dsRNA solution compared with that after soaking in the control solution. Our results suggest that Bxpel1 gene is a significant pathogenic factor in the PWD process and this basic information may facilitate a better understanding of the molecular mechanism of PWD.

Highlights

Pine wilt disease (PWD), which is caused by the pine wood nematode (PWN), Bursaphelenchus xylophilus (Steiner & Buhrer) Nickle, is one of the most serious diseases that damages coniferous forests [1,2,3,4]
Morphology of B. xylophilus after Double-Stranded RNA Interference We performed an experiment to determine the differences in morphology of B. xylophilus with and wWiethpoeurftodrmsReNdAani ienxpoerrdimeretnot etoludceidteartme itnheetehfefedcitfsfeoref nRcNesAini omnoBrp. hxoylopghyiloufsB
The results of our study demonstrated that B. xylophilus is susceptible to RNA interference (RNAi), and that Bxpel1 plays a critical role in the PWD process

Summary

Introduction

Pine wilt disease (PWD), which is caused by the pine wood nematode (PWN), Bursaphelenchus xylophilus (Steiner & Buhrer) Nickle, is one of the most serious diseases that damages coniferous forests [1,2,3,4]. The nematode feeds mainly on the xylem ray parenchyma cells of healthy pine trees [9]. There are various control methods to prevent the dispersal of PWD and many studies have focused on the pathogenic mechanism of B. xylophilus by sequencing analysis [10,11,12]. When invading their hosts, PWNs need to break down the cell wall barrier in pine trees. Pectin is an essential component of the plant cell wall, PWNs need to secrete a mixture of

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