Functional characterization of SURF-1 genes in Arabidopsis thaliana

GRAS DE; GONZÁLEZ DH

Foz Iguazú

Congreso; 11th Congress of International Plant Molecular Biology; 2015

Cytochrome c oxidase (COX)biogenesis is a complex process that requires the action of multiple factorsincluding SURF1 proteins. SURF1 deficiency is a mitochondrial disorder and isthe most frequent cause of Leigh syndrome associated with COX deficiency inhumans. The role of SURF1 in plants still remains unknown. SURF1 is encoded bytwo genes, SURF1-1 and SURF1-2, in Arabidopsis thaliana. Heterozygotesurf1-1 mutant plants produce 25% abnormal seeds with defective embryosarrested at the cotyledon stage, showing that SURF1-1 function isessential at early stages of plant development. surf1-2 mutant plantsexhibit a shortened hypocotyl phenotype under low white light. Histochemicalanalysis using SURF1-2 promoter GUS fusions showed that expressionlevels increase in elongating hypocotyls. Interestingly, shortened elongation of the surf1-2 mutant hypocotylswas recovered in the presence of exogenous GA and IAA. Taken together, ourresults suggest that SURF1-2 is capable of regulating the elongation of Arabidopsishypocotyls acting on GA and auxin homeostasis.