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

ABSTRACT

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.

KEYWORDS:

• Dark septate endophyte
• Darksidea
• fungal bioremediation
• Fusarium
• heavy metal contamination
• root-associated Ascomycota

ACKNOWLEDGMENTS

We thank Paul Owen-Smith, Roxanne Marquez, Amanda Anderson, Purbendra Yogi, and Tonny Nyonga for laboratory assistance. Additional assistance was provided by C. DeVore and T. Busch (Department of Civil Engineering, University of New Mexico).

DISCLOSURE STATEMENT

No potential conflict of interest was reported by the authors.

SUPPLEMENTARY MATERIAL

Supplemental data for this article can be accessed online at https://doi.org/10.1080/00275514.2022.2156746.

Additional information

Funding

This work was supported by National Science Foundation grants NSF-DEB 1911451 COLLABORATIVE RESEARCH: Quantifying the microbial contribution to community recovery from drought and NSF-DEB 1456955 COLLABORATIVE RESEARCH: Parsing the effects of host specificity and geography on plant-fungal symbioses under climate change.