THE GAMMA CARBONIC ANHYDRASE DOMAIN IS ESSENTIAL FOR MITOCHONDRIAL COMPLEX I VIABILITY AND EMBRYO DEVELOPMENT IN ARABIDOPSIS

CORDOBA JUAN PABLO; FASSOLARI S; MARCHETTI, MARIA FERNANDA; SOTO DEBORA; PAGNUSSAT G; EDUARDO JULIAN ZABALETA

Chascomus

Taller; IV Taller de Biología celular y Desarrollo; 2018

Mitochondria are involved in several mechanisms and metabolic pathways. One of the main func=onsthey possess is the cellular ATP synthesis through Electron Transport Chain (ETC). The biggest proteincomplex of ETC (and all mitochondria) is the NADH dehydrogenase complex or Complex I, which is themain entrance of electrons. Through the evolu=on, and organism complexa=on, the Complex I gainedmore protein subunits called ?accessory subunits?. An example of this is the presence of highly similarsubunits to gamma-type carbonic anhydrases (gammaCAs), which are grouped into the CA Domain. InArabidopsis thaliana, five members (CA1, CA2, CA3, CAL1 and CAL2) compose the gammaCA family.Since single null mutant plants did not show visible altera=ons, mul=ple null mutants were studied. Inthis way, we found that disrup=on of CA1/CA2 or CA1/CA3 genes leads to delay on embryodevelopment and inability of embryos to survive a}er germina=on. Developing embryos showdeficiencies in mitochondrial ac=vity, with highly reac=ve oxygen species accumula=on, null fullyassembled complex I and therefore, absence of NADH dehydrogenase ac=vity. In addi=on, these doublemutants show altera=ons in reserve accumula=on, such as abnormal oil storage in oil bodies indeveloping seeds. Despite double mutant seedlings are unable to survive, sucrose supplementa=on?rescues? that phenotype. Finally, a discussion about complex I essen=ality for plant life is proposed.