Characterization of root-associated fungi and reduced plant growth in soils from a New Mexico uranium mine

Characterizing the diverse, root-associated fungi in mine wastes can accelerate the development of bioremediation strategies to stabilize heavy metals. Ascomycota fungi are well known for their mutualistic associations with plant roots and, separately, for roles in the accumulation of toxic compounds from the environment, such as heavy metals. We sampled soils and cultured root-associated fungi from blue grama grass (Bouteloua gracilis) collected from lands with a history of uranium (U) mining and contrasted against communities in nearby, off-mine sites. Plant root-associated fungal communities from mine sites were lower in taxonomic richness and diversity than root fungi from paired, off-mine sites. We assessed potential functional consequences of unique mine-associated soil microbial communities using plant bioassays, which revealed that plants grown in mine soils in the greenhouse had significantly lower germination, survival, and less total biomass than plants grown in off-mine soils but did not alter allocation patterns to roots versus shoots. We identified candidate culturable root-associated Ascomycota taxa for bioremediation and increased understanding of the biological impacts of heavy metals on microbial communities and plant growth.

Automated summary

Characterizing root-associated fungi in mine wastes is important for bioremediation strategies. Ascomycota fungi have both mutualistic associations with plant roots and accumulate heavy metals. Fungal communities in mine sites were less diverse than off-mine sites, and plant growth in mine soils was negatively affected. Identification of candidate fungi for bioremediation and understanding the effects of heavy metals on microbial communities and plant growth are crucial.