Microbial diversity in Antarctic Dry Valley soils across an altitudinal gradient

Frontiers in Microbiology

Microbiology

Pedro H. Lebre¹  Don A. Cowan¹  Lefentse Mashamaite¹  Silindile Maphosa¹  Max Ortiz²  Gilda Varliero³  Ian D. Hogg⁴ 

[1] Department of Biochemistry, Genetics and Microbiology, Centre for Microbial Ecology and Genomics, University of Pretoria, Pretoria, South Africa;Department of Biochemistry, Genetics and Microbiology, Centre for Microbial Ecology and Genomics, University of Pretoria, Pretoria, South Africa;Clemson University Genomics & Bioinformatics Facility, Clemson University, Clemson, SC, United States;Department of Biochemistry, Genetics and Microbiology, Centre for Microbial Ecology and Genomics, University of Pretoria, Pretoria, South Africa;Rhizosphere Processes Group, Swiss Federal Research Institute WSL, Birmensdorf, Switzerland;Department of Biochemistry, Genetics and Microbiology, Centre for Microbial Ecology and Genomics, University of Pretoria, Pretoria, South Africa;School of Science, University of Waikato, Hamilton, New Zealand;Canadian High Arctic Research Station, Polar Knowledge Canada, Cambridge Bay, NU, Canada;

关键词: Antarctic microbiology;    McMurdo Dry Valleys;    edaphic habitats;    microbial diversity;    altitudinal gradients;   

DOI  :  10.3389/fmicb.2023.1203216

 received in 2023-04-10, accepted in 2023-06-23,  发布年份 2023

来源: Frontiers

【 摘 要 】

IntroductionThe Antarctic McMurdo Dry Valleys are geologically diverse, encompassing a wide variety of soil habitats. These environments are largely dominated by microorganisms, which drive the ecosystem services of the region. While altitude is a well-established driver of eukaryotic biodiversity in these Antarctic ice-free areas (and many non-Antarctic environments), little is known of the relationship between altitude and microbial community structure and functionality in continental Antarctica.MethodsWe analysed prokaryotic and lower eukaryotic diversity from soil samples across a 684 m altitudinal transect in the lower Taylor Valley, Antarctica and performed a phylogenic characterization of soil microbial communities using short-read sequencing of the 16S rRNA and ITS marker gene amplicons.Results and DiscussionPhylogenetic analysis showed clear altitudinal trends in soil microbial composition and structure. Cyanobacteria were more prevalent in higher altitude samples, while the highly stress resistant Chloroflexota and Deinococcota were more prevalent in lower altitude samples. We also detected a shift from Basidiomycota to Chytridiomycota with increasing altitude. Several genera associated with trace gas chemotrophy, including Rubrobacter and Ornithinicoccus, were widely distributed across the entire transect, suggesting that trace-gas chemotrophy may be an important trophic strategy for microbial survival in oligotrophic environments. The ratio of trace-gas chemotrophs to photoautotrophs was significantly higher in lower altitude samples. Co-occurrence network analysis of prokaryotic communities showed some significant differences in connectivity within the communities from different altitudinal zones, with cyanobacterial and trace-gas chemotrophy-associated taxa being identified as potential keystone taxa for soil communities at higher altitudes. By contrast, the prokaryotic network at low altitudes was dominated by heterotrophic keystone taxa, thus suggesting a clear trophic distinction between soil prokaryotic communities at different altitudes. Based on these results, we conclude that altitude is an important driver of microbial ecology in Antarctic ice-free soil habitats.

【 授权许可】

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Copyright © 2023 Mashamaite, Lebre, Varliero, Maphosa, Ortiz, Hogg and Cowan.