Study of mitochondrial gamma carbonic anhydrases in the diatom Halamphora coffeaeformis str. Bahía Blanca Estuary

POPOVICH, CA; ZABALETA, E; CAINZOS, M; CÓRDOBA, JP; LEONARDI, PI; PAGNUSSAT, G

Buenos Aires

Congreso; Reunión Conjunta de Sociedades de BioCiencias; 2017

SAIB

Diatoms are responsible for 20?25% of total terrestrial primary production and approximately 40% of annual marine biomass production, which make the most dominant group of organisms sequestering carbon from the atmosphere. It has been proposed that the high photosynthetic efficiency of diatoms is mainly based on the close relationship between their mitochondria and chloroplasts. In previous studies in our laboratory, we have shown that the mitochondrial gamma carbonic anhydrases (CA´s) forming the CA domain of the mitochondrial complex I are important components involved in complex I assembly, in development and in the basal carbon concentrating mechanism in plants. Now we are studying the role of the gammaCA´s in diatoms. In all sequenced genomes of diatoms, we found at least three gammaCAs predicted to be in mitochondria as in plants. We cloned partial sequences of gammaCA´s and other genes from a highly oil productive strain (Bahía Blanca Estuary, 38° 45´ S, 62| 22´ W) of H. coffeaeformis. This strain has around 80% nucleotide identity with a north-american H.coffeaeformis strain (SRX691230) for which a RNA-seq experiment has been performed. We then proposed that both are both different strains of H coffeaeformis. We found that the enriched CO2 atmosphere has a direct positive impact in the growth of H.coffeaeformis. In this context, we are studying, by silencing strategies, the role of the mitochondrial gammaCA´s in the growth and development of south American H.coffeaeformis strain.