Transcriptomic response of Pinus massoniana to infection stress from the pine wood nematode Bursaphelenchus xylophilus

Abstract

The pinewood nematode (PWN) Bursaphelenchus xylophilus is a forestry quarantine pest and causes an extremely dangerous forest disease that is spreading worldwide. Due to the complex pathogenic factors of pine wood nematode disease, the pathogenesis is still unknown. B. xylophilus ultimately invades a host and causes death. However, little is known about the defence-regulating process of host pine after infection by B. xylophilus at the molecular level. Therefore, we wanted to understand how Pinus massoniana regulates its response to invasion by B. xylophilus. P. massoniana were artificially inoculated with B. xylophilus solution, while those without B. xylophilus solution were used as controls. P. massoniana inoculated with B. xylophilus solution for 0 h, 6 h, 24 h, and 120 h was subjected to high-throughput sequencing to obtain transcriptome data. At various time points (0 h, 6 h, 24 h, 120 h), gene transcription was measured in P. massoniana inoculated with PWN. At different time points, P. massoniana gene transcription differed significantly, with a response to early invasion by PWN. According to Gene Ontology (GO) classification and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis, P. massoniana response to PWN invasion involves a wide range of genes, including plant hormone signal transformation, flavonoid biosynthesis, amino sugar and nucleoside sugar metabolism, and MAPK signalling pathways. Among them, inoculation for 120 hours had the greatest impact on differential genes. Subsequently, weighted gene coexpression network analysis (WGCNA) was used to analyse transcriptional regulation of P. massoniana after PWN infection. The results showed that the core gene module of P. massoniana responding to PWN was “MEmagenta”, enriched in oxidative phosphorylation, amino sugar and nucleotide sugar metabolism, and the MAPK signalling pathway. MYB family transcription factors with the highest number of changes between infected and healthy pine trees accounted for 20.4% of the total differentially expressed transcription factors. To conclude, this study contributes to our understanding of the molecular mechanism of initial PWN infection of P. massoniana. Moreover, it provides some important background information on PWN pathogenic mechanisms.

Response analysis of Pinus sibirica to pine wood nematode infection through transcriptomics and metabolomics study

“…Numerous studies provide evidence that pine trees undergo genetic changes over time in response to PWN infection. For instance, in P. massoniana , through transcriptomic data analysis, the core gene module in the early stage of response to PWN was identified, and genes closely related to this module were found to play important roles in oxidative phosphorylation, amino sugar, and nucleotide sugar metabolism, as well as the plant MAPK signaling pathway ( An et al., 2023 ). In this study, after expression trend analysis, all genes were divided into 12 clusters.…”

The molecular basis of pine wilt disease resistance inPinus massoniana

“…Pinus massoniana is severely affected by PWD in southern China. Since the disease was first discovered, over 5,000,000 m³ of Pinus forests have been infected (Cai et al, 2021;An et al, 2023;Li et al, 2023). Due to its hardiness and low maintenance costs, P. massoniana is the main cultivated variety of Pinus in impoverished areas of southern China, and it is irreplaceable (Yu et al, 2020;Zhu et al, 2022).…”