TY - JOUR

T1 - Unrecognized diversity and distribution of soil algae from Maritime Antarctica (Fildes Peninsula, King George Island)

AU - Rybalka, Nataliya

AU - Blanke, Matthias

AU - Tzvetkova, Ana

AU - Noll, Angela

AU - Roos, Christian

AU - Boy, Jens

AU - Boy, Diana

AU - Nimptsch, Daniel

AU - Godoy, Roberto

AU - Friedl, Thomas

N1 - Funding Information: This study was supported by the German Science Foundation (DFG), Grant Number 258740995, within the program “Antarctic Research with Comparable Investigations in Arctic Sea Ice Areas (SPP 1158),” extended to TF. Funding Information: We thank Heiko Nakes for helping with the DNA extraction from soil samples, Rolf Daniel for supporting the laboratory work, and Norman Gentsch and Lars Ganzert for initial statistical analyses. We acknowledge the laboratory work of Eleni K. Ehlers with the SchF soil sample and the assistance of Dorothea Hause-Reitner in organizing the collection of the soil samples. We thank the Instituto Antarctico Chileno (INACH-T 28–11) for the logistic fieldwork support. We acknowledge support from the Open Access Publication Funds of Göttingen University.

PY - 2023/6/26

Y1 - 2023/6/26

N2 - Introduction: Eukaryotic algae in the top few centimeters of fellfield soils of ice-free Maritime Antarctica have many important effects on their habitat, such as being significant drivers of organic matter input into the soils and reducing the impact of wind erosion by soil aggregate formation. To better understand the diversity and distribution of Antarctic terrestrial algae, we performed a pilot study on the surface soils of Meseta, an ice-free plateau mountain crest of Fildes Peninsula, King George Island, being hardly influenced by the marine realm and anthropogenic disturbances. It is openly exposed to microbial colonization from outside Antarctica and connected to the much harsher and dryer ice-free zones of the continental Antarctic. A temperate reference site under mild land use, SchF, was included to further test for the Meseta algae distribution in a contrasting environment. Methods: We employed a paired-end metabarcoding analysis based on amplicons of the highly variable nuclear-encoded ITS2 rDNA region, complemented by a clone library approach. It targeted the four algal classes, Chlorophyceae, Trebouxiophyceae, Ulvophyceae, and Xanthophyceae, representing key groups of cold-adapted soil algae. Results: A surprisingly high diversity of 830 algal OTUs was revealed, assigned to 58 genera in the four targeted algal classes. Members of the green algal class Trebouxiophyceae predominated in the soil algae communities. The major part of the algal biodiversity, 86.1% of all algal OTUs, could not be identified at the species level due to insufficient representation in reference sequence databases. The classes Ulvophyceae and Xanthophyceae exhibited the most unknown species diversity. About 9% of the Meseta algae species diversity was shared with that of the temperate reference site in Germany. Discussion: In the small portion of algal OTUs for which their distribution could be assessed, the entire ITS2 sequence identity with references shows that the soil algae likely have a wide distribution beyond the Polar regions. They probably originated from soil algae propagule banks in far southern regions, transported by aeolian transport over long distances. The dynamics and severity of environmental conditions at the soil surface, determined by high wind currents, and the soil algae’s high adaptability to harsh environmental conditions may account for the high similarity of soil algal communities between the northern and southern parts of the Meseta.

AB - Introduction: Eukaryotic algae in the top few centimeters of fellfield soils of ice-free Maritime Antarctica have many important effects on their habitat, such as being significant drivers of organic matter input into the soils and reducing the impact of wind erosion by soil aggregate formation. To better understand the diversity and distribution of Antarctic terrestrial algae, we performed a pilot study on the surface soils of Meseta, an ice-free plateau mountain crest of Fildes Peninsula, King George Island, being hardly influenced by the marine realm and anthropogenic disturbances. It is openly exposed to microbial colonization from outside Antarctica and connected to the much harsher and dryer ice-free zones of the continental Antarctic. A temperate reference site under mild land use, SchF, was included to further test for the Meseta algae distribution in a contrasting environment. Methods: We employed a paired-end metabarcoding analysis based on amplicons of the highly variable nuclear-encoded ITS2 rDNA region, complemented by a clone library approach. It targeted the four algal classes, Chlorophyceae, Trebouxiophyceae, Ulvophyceae, and Xanthophyceae, representing key groups of cold-adapted soil algae. Results: A surprisingly high diversity of 830 algal OTUs was revealed, assigned to 58 genera in the four targeted algal classes. Members of the green algal class Trebouxiophyceae predominated in the soil algae communities. The major part of the algal biodiversity, 86.1% of all algal OTUs, could not be identified at the species level due to insufficient representation in reference sequence databases. The classes Ulvophyceae and Xanthophyceae exhibited the most unknown species diversity. About 9% of the Meseta algae species diversity was shared with that of the temperate reference site in Germany. Discussion: In the small portion of algal OTUs for which their distribution could be assessed, the entire ITS2 sequence identity with references shows that the soil algae likely have a wide distribution beyond the Polar regions. They probably originated from soil algae propagule banks in far southern regions, transported by aeolian transport over long distances. The dynamics and severity of environmental conditions at the soil surface, determined by high wind currents, and the soil algae’s high adaptability to harsh environmental conditions may account for the high similarity of soil algal communities between the northern and southern parts of the Meseta.

KW - Antarctica

KW - distribution

KW - Fildes Peninsula

KW - green algae

KW - paired-end (ITS2) sequencing

KW - soil algae

KW - Xanthophyceae

UR - http://www.scopus.com/inward/record.url?scp=85164671567&partnerID=8YFLogxK

U2 - 10.3389/fmicb.2023.1118747

DO - 10.3389/fmicb.2023.1118747

M3 - Article

AN - SCOPUS:85164671567

VL - 14

JO - Frontiers in microbiology

JF - Frontiers in microbiology

SN - 1664-302X

M1 - 1118747

ER -