Growth Forms and Functional Guilds Distribution of Soil Fungi in Coastal Versus Inland Sites of Victoria Land, Antarctica

Abstract

In Victoria Land, Antarctica, ice-free areas are restricted to coastal regions and dominate the landscape of the McMurdo Dry Valleys. These two environments are subjected to different pressures that determine the establishment of highly adapted fungal communities. Within the kingdom of fungi, filamentous, yeasts and meristematic/microcolonial growth forms on one side and different lifestyles on the other side may be considered adaptive strategies of particular interest in the frame of Antarctic constraints. In this optic, soil fungal communities from both coastal and Dry Valleys sites, already characterized thorough ITS1 metabarcoding sequencing, have been compared to determine the different distribution of phyla, growth forms, and lifestyles. Though we did not find significant differences in the richness between the two environments, the communities were highly differentiated and Dry Valleys sites had a higher evenness compared to coastal ones. Additionally, the distribution of different growth forms and lifestyles were well differentiated, and their diversity and composition were likely influenced by soil abiotic parameters, among which soil granulometry, pH, P, and C contents were the potential main determinants.

Basidiomycetous Yeast, Glaciozyma antarctica, Forming Frost-Columnar Colonies on Frozen Medium

“…Basidiomycetous yeast Mrakia blollopis changed their morphology under different nutrient conditions [ 40 ]; M. blollopis showed yeast cells on eutrophic media and hyphal cells on oligotrophic media. Filamentous growth allows fungi to explore a more excellent surface search for water and nutrients and makes it possible to form aggregates to retain water and nutrients in unconsolidated and sandy soils [ 8 ]. On the other hand, G. antarctica kept the yeast-form under the conditions tested.…”

“…Basidiomycetous yeasts have belonged in Pucciniomycotina , Ustilaginomycotina , and Tremellomycetes in Agricomycotina . Tremellomycetes and Agaricomycetes (known species were filamentous form) were detected in soils near glacial lakes in the McMurdo Dry Valley [ 7 ] and Victoria Land [ 8 ] by DNA metabarcording, and Tremellomycetes were the dominant taxa in these areas. DNA metabarcording suggested that Coprinellus and Pleurotus (both in Agaricomycetes) were included in dominant fungal taxa on rocks in the polar desert of the Ellsworth Mountains [ 9 ].…”

“…Several cold-adapted yeasts, including basidiomycetes, could grow under freezing conditions [ 12 , 13 ] because they were exceptionally well adapted to cold environments where they thrived in combinations of several stressful conditions [ 8 , 14 , 15 ]. Among basidiomycetous yeasts, trehalose and glycerol are well-known frost protectants in yeasts, and trehalose accumulated in the cytoplasm in Mrakia spp.…”

The poly‐extreme tolerant black yeasts are prevalent under high ultraviolet light and climatic seasonality across soils of global biomes

“…The importance of seasonality and fine soil texture in shaping the soil microbial community was recently demonstrated at global scale (Delgado‐Baquerizo et al ., 2016). In addition, soil texture is an important predictor in promoting soil fungal richness globally (Xia et al ., 2020; Ding and Eldridge, 2020), which is consistent with the results of a recent study conducted on black yeasts from soils of Antarctic desert (Canini et al ., 2021). On the other hand, high levels of UV light are known to reduce the abundance of several fungal lineages (Pfendler et al ., 2019) as well as other microbial groups (e.g.…”

“…Yet, for many species, their natural habitat is still unknown and hence their actual ecology remains enigmatic. Recent studies reported them also as fundamental inhabitants of Antarctic soils (Canini et al ., 2021). Despite their prominent contribution to key terrestrial processes, the proportion of black yeasts has been largely neglected in both regional, continental and global‐scale soil surveys (Maestre et al ., 2015; Cox et al ., 2016; Eldridge and Delgado‐Baquerizo, 2018; Egidi et al ., 2019; Větrovský et al ., 2019; Regmi and Huettmann, 2020).…”