Auxin signaling integrates growth responses and adaptative mechanisms during salt stress.

IGLESIAS MJ; TERRILE MC; BARTOLI, C; CASALONGUÉ C

Tucumán

Congreso; 45 Annual Meeting Argentine Society for Biochemistry and Molecular Biology; 2009

Auxin signaling integrates growth responses and adaptative mechanisms during salt stress. Iglesias, María José; Terrile, María Cecilia; Bartoli, Carlos and Casalongué, Claudia. IIB-CONICET-UNMdP, Funes 3250, 4to nivel, 7600, Mar del Plata. E-mail: majoi84@hotmail.com The plant hormone auxin is required for diverse aspects of plant growth and development. In addition, there is an increasing body of evidence on the participation of auxin signaling during the adaptative response to adverse conditions. We have previously reported that the double mutant for auxin receptors, TIR1 and AFB2, modifies root growth and is rather tolerant to abiotic stress. The aim of this work was to study the mechanism involved in the adaptative response of tir1/afb2 mutant under salt and oxidative stress. We demonstrated that tir1/afb2 mutant presents lower levels of superoxide ion and hydrogen peroxide compared to wild-type. Furthermore, this double mutant displays increased gene expression and activity of antioxidant enzymes such as catalase, glutation-S-transferase and ascorbate peroxidase. Under salinity, total and reduced ascorbate content in tir1/afb2 mutant was 3 folds higher than in wild-type plants. These data suggest that auxin could transduce and integrate developmental and environmental signals by modulating components of the antioxidant metabolism. Partially supported by CONICET; UNMDP; ANPCyT.