The impact of pine wilt disease on the endophytic microbial communities structure of Pinus koraiensis

Pine Wilt Disease (PWD) is a devastating pine tree disease characterized by rapid onset, high mortality rate, quick spread, and difficulty in control. Plant microbiome plays a significant role in the development of PWD. However, the endophytic microbial communities of <i>Pinus koraiensis</i> infected by pine wood nematode (PWN) <i>Bursaphelenchus xylophilus</i> remain largely unexplored. In this study, we analyzed the structural changes of endophytic communities of <i>P. koraiensis</i> after infection by the PWN using high-throughput sequencing technology. The results showed that the community structure underwent significant changes as the degree of PWN infection intensified. The diversity and abundance of endophytic fungi in <i>P. koraiensis</i> increased, while those of endophytic bacteria in <i>P. koraiensis</i> decreased during the infection process. Meanwhile, the abundance of some dominant microorganisms has also changed, including species such as <i>Graphilbum</i> and <i>Pseudoalteromonas</i>. Functional prediction analysis showed that the functional composition of endophytic fungi in <i>P. koraiensis</i> was significantly different across the development of PWD, while the composition of endophytic bacteria remained essentially similar. The results indicated that PWN infection had a significant impact on the structure, diversity, abundance, and functional gene composition of endophytic microbial communities in <i>P. koraiensis</i>, and most of the main endophytic microbial groups tended to coordinate with each other. This work provides a better understanding of the changes in endophytic community structure and function caused by PWD infection of <i>P. koraiensis</i>, which may benefit the exploration of potential endophytes for PWN biocontrol.