The Changes of Microbial Communities and Key Metabolites after Early Bursaphelenchus xylophilus Invasion of Pinus massoniana

Abstract

Pine wood nematode, Bursaphelenchus xylophilus, is a worldwide pest of pine trees, spreading at an alarming rate and with great ecological adaptability. In the process of causing disease, the nematode causes metabolic disorders and changes in the endophytic microbial community of the pine tree. However, the changes at the pine nidus during early nematode invasion have not been well studied, especially the differential metabolites, in Pinus massoniana, the main host of B. xylophilus in China. In this study, we analyzed the endophytic bacterial and fungal communities associated with healthy and B. xylophilus-caused wilted pine trees. The results show that 1333 bacterial OTUs and 502 fungal OTUs were annotated from P. massoniana stem samples. The abundance of bacterial communities in pine trees varies more following infection by B. xylophilus, but the abundance changes of fungal communities are less visible. There were significant differences in endophytic microbial diversity between wilted and healthy P. massoniana. In wilted pine trees, Actinobacteria and Bacteroidia were differential indicators of bacterial communities, whereas, in healthy pine trees, Rhizobiales in the Proteobacteria phylum were the major markers of bacterial communities. Meanwhile, the differential markers of fungal communities in healthy pines are Malasseziales, Tremellales, Sordariales, and Fusarium, whereas Pleosporaceae is the key marker of fungal communities in wilted pines. Our study examines the effect of changes in the endophytic microbial community on the health of pine trees that may be caused by B. xylophilus infection. In parallel, a non-targeted metabolomic study based on liquid mass spectrometry (LC-MS) technology was conducted on pine trees inoculated with pine nematodes and healthy pine trees with a view to identifying key compounds affecting early pine lesions. Ultimately, 307 distinctly different metabolites were identified. Among them, the riboflavin metabolic pathway in pine trees may play a key role in the early pathogenesis of pine wood nematode disease.

The novel nematicide chiricanine A suppresses Bursaphelenchus xylophilus pathogenicity in Pinus massoniana by inhibiting Aspergillus and its secondary metabolite, sterigmatocystin

“…Ophiostomatoids and molds are two major fungal families well known for being highly correlated with the propagation and distribution of the PWN (Feng et al, 2022). Although molds do play crucial roles in multiple processes of PWD epidemics (Guo et al, 2020), in a way unlike the known contributions of ophiostomatoids to PWN (important food resources) (An et al, 2022;Cai et al, 2022;Li et al, 2022), how molds are involved in PWD epidemics remains unclear. The present work, for the first time, clarifies how an important genus of molds, Aspergillus, contributes to the PWD epidemic via its secondary metabolite.…”

Integrated skin microbiome and metabolome analyses reveal altered bacterial community composition and metabolites in psoriasis

“…The ultra-high performance (UHP) LC-MS/MS analyses were performed on a Vanquish UHPLC system (Thermo Fisher Scientific, Germering, Germany) with an Orbitrap Q Exactive HF-X mass spectrometer (Thermo Fisher) following prescribed steps. 11 A Q Exactive HF mass spectrometer was operated in positive or negative polarity mode for detection of metabolites. Quality control samples were mixtures of equal volumes of samples from each experiment.…”