Occurrence of arbuscular mycorrhizal fungi on King George Island, South Shetland Islands, Antarctica

Abstract

Arbuscular mycorrhizal fungi make up an important ecological niche in ecosystems, and knowledge of their diversity in extreme environments is still incipient. The objective of this work was to evaluate the density and diversity of arbuscular mycorrhizal fungi in the soil of King George Island in the South Shetland Islands archipelago, Antarctica. For that, soil and roots of Deschampsia antarctica were collected at the brazilian research station in Antarctica. The spore density, species diversity and mycorrhizal colonization in the roots were evaluated. There was a low density of spores (27.4 ± 17.7) and root mycorrhizal colonization (6 ± 5.1%), which did not present statistical difference. Four species of arbuscular mycorrhizal fungi were identified, distributed in two genera: three species of the genus Glomus (Glomus sp1, Glomus sp2 and Glomus sp3) and one of the genus Acaulospora, which was identified at species level (Acaulospora mellea). Greater soil diversity was verified with pH 5.9 and phosphorus concentration of 111 mg dm -3 , occurring two species of genus Glomus and A. mellea. Based on literature data, this may be the first record of this species of Acaulospora mellea in Antarctic soils, colonizing D. antarctica plants.

Global arbuscular mycorrhizal fungal diversity and abundance decreases with soil available phosphorus

“…In comparison to the others, cold zones had lower AMF diversity. The low number and abundance of AMF host plants and C allocation of host plants to symbiosis in cold zones affect the formation of mycorrhizal symbiosis (Barbosa et al, 2017; Barceló et al, 2019; Bueno et al, 2017; Gardes & Dahlberg, 1996; Olsson et al, 2004; Timling et al, 2012). Veresoglou et al (2019) proposed that irradiance constraints in cold zones contribute to a reduction in mycorrhizal responsiveness, and the reduced mycorrhizal responsiveness further induces a decline in AMF species.…”

First Record of Juncaceicola as Endophytic Fungi Associated with Deschampsia antarctica Desv.

“…Although sequences of nuclear ribosomal spacers are widely used for phylogenetic analysis, we must always be careful to avoid over interpretation, since sequences such as ITs can be misleading when incorporated into phylogenies, since these regions are involved in a lower rate in fungi and can be present in many copies in the plant genome [45]. Taking into account that our sample is an endophyte fungus obtained from leaves of an Antarctic plant, selection pressure is higher in the organism living there [46], and the molecular relationships between endophyte fungi and their hosts have not yet been fully established [47], further analyzes are necessary for the taxonomic determination of our new fungi species.…”

Mycorrhiza and Lichens as Two Models of Fungal Symbiosis

“…Occurring in both vascular plants and bryophytes, the environmental tolerance of arbuscular mycorrhiza are, in general, higher than ectomycorrhiza with the former occurring in a wide range of habitat types from desert to saturated and sodic ground (Bernardo et al 2019;Bahadur et al 2019;Wang et al 2019;Lee et al 2020). Consequently, arbuscular mycorrhiza have been found on every continent, including some Antarctic islands (Barbosa et al 2017). The establishment of arbuscular mycorrhiza requires a signalling cascade and this begins with plant-derived strigolactones being perceived by the arbuscular mycorrhiza fungi, which in turn produces chitooligosaccharides and lipochitooligosaccharides (Feng et al 2019;Pons et al 2020).…”