2024 journal article

Environmental drivers and cryptic biodiversity hotspots define endophytes in Earth's largest terrestrial biome

CURRENT BIOLOGY, 34(5).

UN Sustainable Development Goal Categories
Source: Web Of Science
Added: May 7, 2024

Understanding how symbiotic associations differ across environmental gradients is key to predicting the fate of symbioses as environments change, and it is vital for detecting global reservoirs of symbiont biodiversity in a changing world. 1 Arnold A.E. Mejía L.C. Kyllo D. Rojas E.I. Maynard Z. Robbins N. Herre E.A. Fungal endophytes limit pathogen damage in a tropical tree. Proc. Natl. Acad. Sci. USA. 2003; 100: 15649-15654 Crossref PubMed Scopus (1012) Google Scholar ,2 Rodriguez R.J. Henson J. Van Volkenburgh E. Hoy M. Wright L. Beckwith F. Kim Y.O. Redman R.S. Stress tolerance in plants via habitat-adapted symbiosis. ISME J. 2008; 2: 404-416 Crossref PubMed Scopus (799) Google Scholar ,3 Busby P.E. Soman C. Wagner M.R. Friesen M.L. Kremer J. Bennett A. Morsy M. Eisen J.A. Leach J.E. Dangl J.L. Research priorities for harnessing plant microbiomes in sustainable agriculture. PLoS Biol. 2017; 15e2001793 Crossref PubMed Scopus (487) Google Scholar However, sampling of symbiotic partners at the full-biome scale is difficult and rare. As Earth's largest terrestrial biome, boreal forests influence carbon dynamics and climate regulation at a planetary scale. Plants and lichens in this biome host the highest known phylogenetic diversity of fungal endophytes, which occur within healthy photosynthetic tissues and can influence hosts' resilience to stress. 4 U'Ren J.M. Lutzoni F. Miadlikowska J. Zimmerman N.B. Carbone I. May G. Arnold A.E. Host availability drives distributions of fungal endophytes in the imperilled boreal realm. Nat. Ecol. Evol. 2019; 3: 1430-1437 Crossref PubMed Scopus (82) Google Scholar ,5 Arnold A.E. Lutzoni F. Diversity and host range of foliar fungal endophytes: are tropical leaves biodiversity hotspots?. Ecology. 2007; 88: 541-549 Crossref PubMed Scopus (728) Google Scholar We examined how communities of endophytes are structured across the climate gradient of the boreal biome, focusing on the dominant plant and lichen species occurring across the entire south-to-north span of the boreal zone in eastern North America. Although often invoked for understanding the distribution of biodiversity, neither a latitudinal gradient nor mid-domain effect 5 Arnold A.E. Lutzoni F. Diversity and host range of foliar fungal endophytes: are tropical leaves biodiversity hotspots?. Ecology. 2007; 88: 541-549 Crossref PubMed Scopus (728) Google Scholar ,6 Hillebrand H. On the generality of the latitudinal diversity gradient. Am. Nat. 2004; 163: 192-211 Crossref PubMed Scopus (1393) Google Scholar ,7 Colwell R.K. Lees D.C. The mid-domain effect: geometric constraints on the geography of species richness. Trends Ecol. Evol. 2000; 15: 70-76 Abstract Full Text Full Text PDF PubMed Scopus (869) Google Scholar can explain variation in endophyte diversity at this trans-biome scale. Instead, analyses considering shifts in forest characteristics, Picea biomass and age, and nutrients in host tissues from 46° to 58° N reveal strong and distinctive signatures of climate in defining endophyte assemblages in each host lineage. Host breadth of endophytes varies with climate factors, and biodiversity hotspots can be identified at plant-community transitions across the boreal zone at a global scale. Placed against a backdrop of global circumboreal sampling, 4 U'Ren J.M. Lutzoni F. Miadlikowska J. Zimmerman N.B. Carbone I. May G. Arnold A.E. Host availability drives distributions of fungal endophytes in the imperilled boreal realm. Nat. Ecol. Evol. 2019; 3: 1430-1437 Crossref PubMed Scopus (82) Google Scholar our study reveals the sensitivity of endophytic fungi, their reservoirs of biodiversity, and their important symbiotic associations, to climate.