Caracterización funcional del co-activador transcripcional de papa, StMBF1, bajo diferentes condiciones de estrés

ARCE, DÉBORA; TONÓN CLAUDIA; GODOY, ANDREA VERÓNICA; CASALONGUÉ, CLAUDIA ANAHÍ

Iguazú

Congreso; XL Reunión Anual SOCIEDAD ARGENTINA DE INVESTIGACIÓN BIOQUÍMICA Y BIOLOGÍA MOLECULAR; 2004

SAIB

P { margin-bottom: 0.08in; } Multiprotein bridging factors 1 (MBF1) have been described as transcriptional coactivators that mediates transcriptional activation by bridging between an activator and TATA-box binding protein (TBP). We have reported the identification of a Solanum tuberosum transcriptional coactivator named StMBF1, which is up-regulated by biotic and abiotic stress in potato tubers. In this work we described a fast StMBF1 protein accumulation in potato cell suspensions treated with 20 mM H 2O 2. Hydrogen peroxide production is though to be increased under various biotic and abiotic stresses and to enhance gene expression of active oxygen scavenging (AOS) enzymes. To further study the possible role of MBF1 during stress, we persuade its functional characterization in Arabidopsis thaliana. MBF1 protein levels in flower and fruit were higher than in root and leaves. Furthermore, we have developed transgenic antisense lines of the Arabidopsis MBF1c gene and we are also characterizing a T-DNA insertion line in this gene from the SALK collection. Five day-old plants from these lines were treated with 15 mM H2O2 (30 min to 24 h) and analyzed cell death by Evans blue staining. We also tested if high salt concentrations (50-100 mM NaCl) affect root elongation. In both cases, transgenic plants were more susceptible to the stress treatments. All these findings reinforce the role of MBF1 in plant stress responses, although their regulation in the transcriptional mechanism remained unclear.