Host identity and phylogeny shape the foliar endophytic fungal assemblages of Ficus

Abstract

Foliar endophytic fungi (FEF) are diverse and ubiquitously associated with photosynthetic land plants. However, processes shaping FEF assemblages remain poorly understood. Previous studies have indicated that host identity and host habitat are contributing factors, but these factors are often difficult to disentangle. In this study, we studied FEF assemblages from plants grown in a botanical garden, enabling us to minimize the variation in abiotic environmental conditions and fungal dispersal capacity. FEF assemblages from 46 Ficus species were sequenced using next‐generation methods, and the results indicated that closely related host species had clearly differentiated FEF assemblages. Furthermore, host phylogenetic proximity was significantly correlated with the similarity of their FEF assemblages. In the canonical correspondence analysis, eleven leaf traits explained 32.9% of the total variation in FEF assemblages, whereas six traits (specific leaf area, leaf N content, leaf pH, toughness, latex alkaloid content, and latex volume per leaf area) were significant in the first two dimensions of ordination space. In the multiple regression on distance matrix analysis, 21.0% of the total variance in FEF assemblage was explained by both host phylogeny and leaf traits while phylogeny alone explained 7.9% of the variance. Thus, our findings suggest that both evolutionary and ecological processes are involved in shaping FEF assemblages.

Foliar fungal endophyte community structure is independent of phylogenetic relatedness in an Asteraceae common garden

“…The genotypic and phenotypic divergence among host species underlying phylogenetic relationships is complex and undoubtedly includes a wide array of traits that differentially influence colonization success of specific microbial taxa (Liu et al, 2019). For example, research on plant-pathogen interactions suggests that more closely related hosts share similar genetic pathways for cellular recognition of proteins and effector molecules during pathogen colonization and resistance (Barrett & Heil, 2012).…”

“…and tropical forest grasses; Eusemann et al., 2016; Higgins et al., 2014). Similarly, one recent study found that FFE community structure was significantly related to host phylogeny among Ficus tree species in a mixed botanical garden (Liu et al., 2019), but no evidence for host phylogenetic drivers was found among families of trees in a tropical forest (Vincent et al., 2016). Thus, experiments that control for host phylogeny, but minimize broad regional differences in spatial and temporal sampling of host individuals, would be a strong test for the relative importance of host phylogeny versus local ecological conditions on the distribution of FFE.…”

“…The use of a common garden framework allowed us to control for potentially confounding spatial and temporal factors, such as regional‐scale changes in environmental and climatic conditions, long‐distance dispersal limitation of FFE, and host age, by spatially randomizing all species under similar environmental conditions (Kawecki & Ebert, 2004). We predicted that FFE community structure would differ significantly among host species (Laforest‐Lapointe et al., 2017) and that FFE community dissimilarity would be positively associated with phylogenetic divergence among host taxa (Liu et al., 2019). Similarly, we expected to see a positive, though weaker, effect of spatial distance with FFE community dissimilarity across the plots in the common garden due to the limited distance between plots.…”

Fungal communities living within leaves of native Hawaiian dicots are structured by landscape‐scale variables as well as by host plants

“…The association we found between FEF beta diversity and host plant phylogenetic distance was the most important predictor in our GDM model. Previous studies of FEF have surveyed multiple host species and have found that host identity is commonly associated with fungal endophyte community composition (Liu, Zhao, Wang, & Chen, 2019;U'Ren et al, 2012;Vincent et al, 2016), even among closely related hosts (Christian et al, 2020), so our result was mostly expected. But unlike most previous studies that found host associations of FEF (although see Davis & Shaw, 2008), we used the phylogeny of host plants as an explanatory variable in place of their identity.…”

Host Specificity of Endophytic Fungi from Stem Tissue of Nature Farming Tomato (Solanum lycopersicum Mill.) in Japan

“…The plant and endophytes coevolved millions of years ago [1]. The composition of endophytic fungi is often diversified [2][3][4], and may vary as a function of host plant species [5,6], geographically distanced individuals of the same host species, and within the tissues or organs of a host plant [7]. In plant-endophyte mutualistic symbiosis, plants provide accommodation and diverse niches for endophytes [8].…”