Silencing of mitochondrial gammaCAs using small interfering and micro RNAs. Soto D, Cordoba JP, Pagnussat G, Braun HP and Zabaleta E

SOTO DEBORA; CORDOBA JUAN PABLO; PAGNUSSAT G; BRAUN, H.; ZABALETA, E

San Luis

Congreso; Sociedad Argentina de Investigación Bioquímia y Biología Molecular SAIB; 2011

The gene family of putative gamma-class Carbonic Anhydrases (CA) in Arabidopsis genome includes five members. Three of these genes (CA1, CA2 and CA3), share high homology with the highly characterized gamma-CAs from the archaea M. thermophila, and two CA-Like genes (CAL1 and CAL2) showing a minor degree of homology. CA and CAL proteins are located into mitochondria and bonded to mitochondrial Complex I, forming an extra domain exclusive of photosynthetic organisms. However, the physiological function of this plant specific extra domain is largely unknown. Single mutants do not show a visible phenotype although ca2 null mutant shows 90% reduction of mitochondrial complex I. Thus, partial redundancy might exists. In order to gain insight about this redundancy, several approaches to silence multiple genes encoding proteins of the CA domain were undertaken. Using a microRNA designer tool, 35S::amiRCAs and 35S::amiRCALs were constructed and introduced into Arabidopsis thaliana, var Col-0. On the other hand, a specific 200 bp to perform siRNA against CAs or CALs using pHANNIBAL or pOpOff2 (dexamethasone inducible) vectors were independently introduced into Col-0. Physiological parameters such as oxygen consumption, carbon dioxide fixation and preliminary mitochondrial proteomic analyses were compared with those of single and double null mutants.