Andean páramo plant root-associated fungal metagenomics
The Páramo ecosystem in the high-altitude tropical Andes constitutes grasslands characterized by extreme environmental conditions and exceptional plant diversity, making it the world's coldest biodiversity hotspot. Despite the high concentration of endemic Ericaceae species within the páramo region, their root-associated fungal communities, including ericoid mycorrhizae, remain poorly explored. This study provides the first large-scale assessment of fungal diversity associated with Ericaceae roots across altitudinal gradients (2,700 to 3,800 m.a.s.l.) in the Tropical Andes, using Gaultheria myrsinoides as a model plant. Through DNA metabarcoding of the ITS2 region from root and soil samples collected at 12 locations across four páramo regions, we identified over 4,700 fungal OTUs associated with the roots, and 3,600 in the surrounding soil.   We documented that elevation is a primary driver of fungal community structure, with alpha diversity consistently decreasing with altitude and accompanied by shifts in fungal community composition. Additionally, each site harbored distinct fungal communities, reflecting the isolated nature of the páramo ecosystem. The fungal order Helotiales emerged as the dominant group within root-associated communities, comprising an average of 58% of the community and increasing in abundance with elevation. In contrast, Sebacinales—the second most abundant order, averaging 9% in relative abundance—showed a consistent decrease with elevation. Our results suggest a biogeographical pattern of Helotiales dominance in the mycobiome of Ericaceae roots in the high-altitude Andes. Notably, several potential ericoid mycorrhizal fungal genera—including Serendipita, Leohumicola, Lachnum, Pezicula, Capronia, Oidiodendron, Meliniomyces, and Hyaloscypa—were identified in the roots of Gaultheria myrsinoides. These findings offer unprecedented insights into the fungal diversity associated with Ericaceae roots in the high tropical Andes, addressing critical gaps in understanding root-associated fungal communities in high-elevation tropical ecosystems.
The Páramo ecosystem in the high-altitude tropical Andes constitutes grasslands characterized by extreme environmental conditions and exceptional plant diversity, making it the world's coldest biodiversity hotspot. Despite the high concentration of endemic Ericaceae species within the páramo region, their root-associated fungal communities, including ericoid mycorrhizae, remain poorly explored. This study provides the first large-scale assessment of fungal diversity associated with Ericaceae roots across altitudinal gradients (2,700 to 3,800 m.a.s.l.) in the Tropical Andes, using Gaultheria myrsinoides as a model plant. Through DNA metabarcoding of the ITS2 region from root and soil samples collected at 12 locations across four páramo regions, we identified over 4,700 fungal OTUs associated with the roots, and 3,600 in the surrounding soil.   We documented that elevation is a primary driver of fungal community structure, with alpha diversity consistently decreasing with altitude and accompanied by shifts in fungal community composition. Additionally, each site harbored distinct fungal communities, reflecting the isolated nature of the páramo ecosystem. The fungal order Helotiales emerged as the dominant group within root-associated communities, comprising an average of 58% of the community and increasing in abundance with elevation. In contrast, Sebacinales—the second most abundant order, averaging 9% in relative abundance—showed a consistent decrease with elevation. Our results suggest a biogeographical pattern of Helotiales dominance in the mycobiome of Ericaceae roots in the high-altitude Andes. Notably, several potential ericoid mycorrhizal fungal genera—including Serendipita, Leohumicola, Lachnum, Pezicula, Capronia, Oidiodendron, Meliniomyces, and Hyaloscypa—were identified in the roots of Gaultheria myrsinoides. These findings offer unprecedented insights into the fungal diversity associated with Ericaceae roots in the high tropical Andes, addressing critical gaps in understanding root-associated fungal communities in high-elevation tropical ecosystems.
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