PHOTORECEPTORS DISTRIBUTION FOLLOWS A LIGHT GRADIENT IN MODERN STROMATOLITES FROM LAKE SOCOMPA (4,570 M), HIGH-ANDES PUNA REGION

ALONSO REYES, DANIEL GONZALO; IRAZOQUI, JOSE MATIAS; AMADIO, ARIEL; TSCHOEKE, DIOGO; THOMPSON, FABIANO; FARÍAS, MARÍA EUGENIA; ALBARRACÍN, VIRGINIA HELENA

París

Conferencia; M-fed 2021 Workshop & Conference; 2021

Muséum National d?Histoire Naturelle (MNHN)

Modern non-lithifying stromatolites on the shore of the volcanic lake Socompa (STs) in the Puna are affected by several extreme conditions. The present study assesses for the first time light utilization of STs on a millimeter scale through shotgun metagenomics. The analysis on ST unveiled a high abundance of genes for UV-screening, oxidant-quenching pigments, and CPF (photoreactivation) in the UV-stressed layers which could indicate that the zone itself works as an UV-shield. There is a remarkable density of sequences associated photoreceptors in the first two layers. Also, genetic evidence of photosynthesis split in eukaryotic (layer 1) and prokaryotic (layer 2). Photoheterotrophic bacteria, aerobic photoautotrophic bacteria and anaerobic photoautotrophic bacteria coexist by selectively absorbing different parts of the light spectrum (blue, red and IR respectively) at different positions of the mat.