STUDY OF MITOCHONDRIAL GAMMA CARBONIC ANHYDRASES IN THE DIATOM HALAMPHORA COFFEAEFORMIS STR. BAHÍA BLANCA ESTUARY

CAINZOS MAXIMILIANO; CORDOBA JUAN PABLO; POPOVICH, CECILIA; LEONARDI, PATRICIA; PAGNUSSAT G; EDUARDO JULIAN ZABALETA

Buenos Aires

Congreso; REUNIÓN CONJUNTA DE SOCIEDADES DE BIOCIENCIAS; 2017

SAIB

Diatoms are responsible for 25% of total terrestrial primary productionand approximately 40% of annual marine biomass production,which make the most dominant group of organisms sequesteringcarbon from the atmosphere. It has been proposed that the highphotosynthetic efficiency of diatoms is mainly based on the closerelationship between their mitochondria and chloroplasts. In previousstudies in our laboratory, we have shown that the mitochondrialgamma carbonic anhydrases (CA?s) forming the CA domain ofthe mitochondrial complex I are important components involved incomplex I assembly, in development and in the basal carbon concentratingmechanism in plants. Now we are studying the role ofthe gammaCA?s in diatoms. In all sequenced genomes of diatoms,we found at least three gammaCAs predicted to be in mitochondriaas in plants. We cloned partial sequences of gammaCA?s and othergenes from a highly oil productive strain (Bahía Blanca Estuary,38° 45? S, 62| 22? W) of H. coffeaeformis. This strain has around80% 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 directpositive impact in the growth of H.coffeaeformis.. In this context,we are studying, by silencing strategies, the role of the mitochondrialgammaCA?s in the growth and development of south AmericanH.coffeaeformis strain.