The interaction between Septoria stem canker and the mycobiome of Populus trichocarpa stems

mSystems

卷:11

Research Article

Morgan G. A. Miller¹  Gillian E. Bergmann¹  Ricardo I. Alcalá Briseño¹  Yung-Hsiang Lan¹  Kelsey L. Søndreli¹  Posy E. Busby¹  Jared M. LeBoldus^1,2 

[1] Forest Engineering, Resources and Management Department, Oregon State University, Corvallis, Oregon, USA

[2] Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon, USA

关键词: microbiome;    microbial invasion;    Sphaerulina musiva;    Septoria canker;    poplar;    phytobiome;    microbial ecology;   

DOI  :  10.1128/msystems.00055-26

 received in 2026-01-15, accepted in 2026-05-07,  发布年份 2026

来源: American Society for Microbiology

【 摘 要 】

ABSTRACTSphaerulina musiva, a fungal pathogen causing leaf spot and canker disease of poplar trees (Populus spp.), was recently introduced to the Pacific Northwest, where it threatens commercially valuable plantations and native riparian ecosystems. Vascular tissue was collected from the stems of 410 symptomatic and asymptomatic trees in an S. musiva-infested Populus trichocarpa plantation. Resident fungal endophyte communities were characterized with ITS amplicon sequencing. Canker expression and S. musiva presence corresponded with reduced fungal diversity across multiple indices. Fungal endophyte communities of symptomatic tissues were frequently dominated by S. musiva and thus compositionally distinct from those of asymptomatic tissues. Asymptomatic-tissue communities from healthy and diseased stems did not differ in composition or diversity, indicating disease-associated low-diversity mycobiome states are local to the cankered site. The relative abundance of S. musiva was positively correlated with stem cankering. S. musiva was negatively correlated with key non-pathogenic fungal endophytes, which were themselves strongly inter-correlated. Our results illustrate S. musiva’s ability to exploit the vascular microhabitat of susceptible Populus trichocarpa stems and dominate resident fungal assemblies at the site of infection.IMPORTANCEPlant-associated microbial communities can both mediate and be modified by pathogen infection. Thus, understanding disease outcomes of complex plant pathosystems requires characterization of pathogen-phytobiome interactions. Efforts to characterize these interactions have yielded microecological insights with applied relevance for disease management in herbaceous leaf- and root-associated pathosystems. However, pathogen-phytobiome interactions in the vascular tissues of hardwood stems remain largely unexplored. Our findings illuminate the ecological organization of the Populus trichocarpa stem mycobiome under S. musiva disease pressure and advance understanding of microfungal community dynamics in the Septoria stem canker pathosystem. Additionally, we identify potentially interactive fungal taxa that may disproportionately shape mycobiome structure and disease dynamics in Populus trichocarpa stems.

【 授权许可】

CC BY   
Copyright © 2026 Miller et al.

【 图 表 】

Fig 3

Fig. 1