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

ROXANA COLOMBO; VANESA SILVANI; SCORZA MARIA VICTORIA; FERNÁNDEZ BIDONDO LAURA; ROTHEN CAROLINA; BENAVIDEZ MATIAS; SCOTTI ADALGISA; PERGOLA MARIANA; SEBASTIAN FRACCHIA; ALICIA GODEAS

Arizona

Conferencia; ICOM 8; 2015

International Mycorrhiza Society

The Laguna Brava wetland is a stressful habitat in the Andean Mountains(Argentina) dominated by extreme abiotic factors: high altitude (4300 m abovesea level) and UV radiance, hypersalinity, alkalinity, and high heavy metal contentin soils. Organisms have evolved in order to survive under these extremeconditions. The sparse vegetation that inhabits this wetland is frequentlycolonized by arbuscular mycorrhizal (AM) fungi. However, it is unknown which AMspecies can survive in such a harsh environment and how it may affect thestructure of AM community. To answer these questions, 454 ampliconpyrosequencing and morphological (based on spore traits) approaches were usedfor assessing fungal diversity. Physical and chemical soil analyses were alsoperformed. A total of 22 molecular operational taxonomic units (MOTUs) and 29morphospecies of AM fungi were identified. Glomeraceae and Claroideoglomeraceaewere the dominant families. AM community composition differed significantlybetween sampled sites. AM fungi were not detected in two sites with highelectrical conductivity, Na, Sr, U, Pb, and As content in soils. Some MOTUswere found in all the remaining three sites, while others were specific of eachsite. Plant and AM communities were more diverse and equitable in soils withhigh organic matter, N, and P. Spore density dramatically decreased withsalinity. In the most saline soils, Rhizophagus af. intraradices-irregularis andClaroideoglomus species were the most abundant taxa. Both methodologies showedthat cosmopolitan AM species that occur across a broad range of environmentsalso occurred in this habitat. Our results strongly suggest that presence of AMfungi and their community structure are strongly associated with local environmentalvariations in Laguna Brava. This study represents the first metagenomicanalysis of AM fungal community in high Andean wetland in Argentina, improvingthe knowledge about these fungi in extreme environments