AUTHOR=Tanunchai Benjawan , Ji Li , Schroeter Simon Andreas , Wahdan Sara Fareed Mohamed , Larpkern Panadda , Lehnert Ann-Sophie , Alves Eliane Gomes , Gleixner Gerd , Schulze Ernst-Detlef , Noll Matthias , Buscot François , Purahong Witoon TITLE=A poisoned apple: First insights into community assembly and networks of the fungal pathobiome of healthy-looking senescing leaves of temperate trees in mixed forest ecosystem JOURNAL=Frontiers in Plant Science VOLUME=Volume 13 - 2022 YEAR=2022 URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.968218 DOI=10.3389/fpls.2022.968218 ISSN=1664-462X ABSTRACT=Despite the abundance of observations of foliar pathogens, our knowledge is severely lacking regarding how the fungal pathobiome is structured and which processes determine community assembly. In this study, we addressed these questions by analysing the fungal pathobiome associated with the senescing leaves and needles of 12 temperate tree species. We compared fungal pathogen load in the senescing leaves and demonstrated that healthy-looking leaves are inhabited by diverse and distinct fungal pathogens. We detected 400 fungal pathogenic ASVs belonging to 130 genera. The pathogenic generalist, Mycosphaerella, was found to be the potential most significant contributor to foliar disease in seedlings. The analyses of assembly process and co-occurrence network showed that the fungal pathogenic communities in different tree types are mainly determined by stochastic processes. However, the homogenising dispersal highly contributes in broadleaf trees, whereas ecological drift plays an important role in conifer trees. The deterministic assembly processes (dominated by variable selection) contributed more in broadleaf trees as compared to coniferous trees. We found that pH and P levels significantly correspond with fungal pathogenic community compositions in both tree types. Our study provides the first insight and mechanistic understanding into the community assembly, networks, and complete taxonomy of the foliar fungal pathobiome in senescing leaves and needles.