Intergenerational and horizontal transmission of wheat endophytic fungi

Understanding the mechanisms of endophytic fungal transmission is crucial for deciphering plant-microbe interactions and leveraging microbiomes in crop improvement. In this study, we examined the potential for intergenerational inheritance and external recruitment of endophytic fungi in common wheat. Fungal community structure was compared in generation G1 and parental G0 plants using ITS2 metabarcoding data and culture-based identification in four tissues (roots, stems, leaves, and seeds) in ten cultivars. A set of 27 operational taxonomic units (OTUs) was consistently detected in both generations, suggesting the presence of a core mycobiome dominated by genera such as Fusarium, Trichoderma, Penicillium, Cladosporium, Sarocladium and Lecanicillium. Experimental inoculation of axenic wheat seedlings with fungi Fusarium proliferatum, Penicillium expansum, Trichoderma hamatum originating from the wheat endosphere confirmed the ability of these species to recolonize host tissues and thus their role in stable association with plants. However, several other taxa (Engyodontium album, Sarocladium spinificis, Clonostachys candelabrum, and Nigrospora gorlenkoana) originating from internal wheat tissues failed to recolonize axenic plants, suggesting transient colonization via horizontal pathways. These findings highlight the dual contribution of vertical inheritance and environmental recruitment in shaping the wheat endomycobiome, offering a foundation for targeted manipulation of beneficial fungi in cereal crops.