Are mycoheterotrophs actually parasites? Proximity-based ITS metabarcoding of fungal communities associated with Sarcodes sanguinea and Corallorhiza striata Raw sequence reads

This study investigates how mycoheterotrophic plants influence the structure and spatial distribution of ectomycorrhizal fungal communities in forest soils. Using ITS1 DNA metabarcoding, we analyzed rhizosphere soil samples collected at varying distances from the root systems of two mycoheterotrophic plant species (Sarcodes sanguinea (Ericaceae) and Corallorhiza striata (Orchidaceae)) to assess whether their known fungal symbionts (Rhizopogon ellenae and Tomentella fuscocinerea, respectively) exhibit localized enrichment patterns. By comparing the relative abundance and community composition of fungi across distance gradients, this research provides new insights into the structuring effects of plant-fungal specificity and parasitism on ectomycorrhizal networks. Findings have implications for understanding common mycorrhizal networks, symbiotic specificity, and the ecological role of mycoheterotrophs in forest ecosystems.