ANALYSIS OF AN OXIDATIVE STRESS TOLERANT MUTANT OF Arabidopsis thaliana

BONDINO, H.G.; SCARPECI, T.E.; CARRILLO, N.; VALLE, E.M.

Rosario, Santa Fe

Congreso; SAIB 2006; 2006

SAIB

The goal of this study is the analysis of a mutant line of Arabidopsis thaliana with a phenotype of tolerance to methyl viologen (MV). This mutant was isolated in an assay aimed to identify lines tolerant to oxidative stress, in which 8,850 independent lines that had been mutated by activation tagging (Weigel et al., 2000) were exposed to MV. A line named 44/1 was isolated and the T-DNA insertion site in the Arabidopsis genome was identified using the plasmid rescue technique. Sequencing of the rescued plasmids revealed that the T-DNA had been inserted within the activation range of two genes, one of unknown function (UFG) and one that codes for a 2-Cys peroxiredoxine (2-Cys Prx). The participation of both genes as candidates responsible for the oxidative stress tolerant phenotype was analyzed in silico. Although the 2-Cys Prx gene was the most likely candidate owing to the involvement of this protein in the antioxidant defense, the analysis of the expression of these genes revealed that the UFG could be responsible for the phenotype. This is indicated by the variation of the mRNA levels of UFG, which increased when exposed to oxidative stress, while the mRNA levels of 2-Cys Prx remained constant