Arbuscular mycorrhizal fungal diversity in high-altitude hypersaline andean wetlands studied by 454 pyrosequencing metagenomic and morphological approaches.

COLOMBO R; SILVANI VA; SCORZA M V; FERNÁNDEZ BIDONDO LAURA; ROTHEN CAROLINA; SCOTTI ADALISA; FRACCHIA S; GODEAS AM

Flagstaff

Congreso; Conferencia; International Conference on Mycorrhiza 8; 2015

International Mycorrhizal Society

The Laguna Brava wetland is a stressful habitat in the Andean Mountains (Argentina) dominated by extreme abiotic factors: high altitude (4300m above sea level) and UV radiance, hypersalinity, alkalinity, and high heavy metal content in soils. Organisms have evolved in order to survive under these extreme conditions. The sparse vegetation that inhabits this wetland is frequently colonized by Arbuscular Mycorrhizal (AM) fungi. But it is unknown which AM species can survive in such harsh environment and how it may affect the structure of AM community. To answer these questions, 454 amplicon pyrosequencing and morphological (based on spore traits) approaches were used for assessing fungal diversity. Physical and chemical soil analyses were also performed. A total of 22 molecular operational taxonomic units (MOTUs) and 29 morphospecies of AM fungi were identified. Glomeraceae and Claroideoglomeraceae were the dominant families. AM community composition differed significantly between sampled sites. AM fungi were not detected in two sites with high electrical conductivity, Na, Sr, U, Pb and As content in soils. Some MOTUs were found in all the remaining three sites, while others were specific of each site. Plant and AM communities were more diverse and equitable in soils with high organic matter, N and P. Spore density dramatically decreased with salinity. In the most saline soils, Rhizophagus af. intraradices-irregularis and Claroideoglomus species were the most abundant taxa. Both methodologies showed that cosmopolitan AM species that occur across a broad range of environments also occurred in this habitat. Our results strongly suggest that presence of AM fungi and their community structure are strongly associated with local environmental variations in Laguna Brava. This study represents the first metagenomic analysis of AM fungal community in high Andean wetland in Argentina, improving the knowledge about these fungi in extreme environments.