Auxin signaling integrates growth responses and adaptative mechanisms during salt stress

IGLESIAS, MARÍA JOSÉ; TERRILE, MARÍA CECILIA; BARTOLI, CARLOS GUILLERMO; CASALONGUÉ, CLAUDIA

San Miguel de Tucumán

Congreso; XLV Reunión Annual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2009

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular

The plant hormone auxin is required for diverse aspects of plant growth and development. However, there is an increasing body of evidence on the participation of auxin signaling also during the adaptative response to adverse conditions. We have previously reported that the double mutant for auxing receptors (TIR1 and AFB2) modifies root grwoth and is rather tolerant to abiotic stress. The aim of this work was to study the mechanism involved in the adaptative response of tir2/afb2 mutant to 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, gluathione-S-transferase and ascorbate peroxidase. Under salinity, total and reduced ascorbate concentration in tir1/afb2 mutant was higher than in wild-type plants. These data suggest that auxin could transduce and integrate devolpmental and environmental signals by modulating components of the antioxidant metabolism.