INVESTIGADORES
CHAN Raquel Lia
congresos y reuniones científicas
Título:
Glucanase proteins are involved in freezing stress tolerance in Arabidopsis
Autor/es:
CABELLO JV; CHAN RL
Lugar:
San Miguel de Tucumán
Reunión:
Congreso; XLV Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2009
Institución organizadora:
SAIB
Resumen:
GLUCANASE PROTEINS ARE INVOLVED IN FREEZING STRESS TOLERANCE IN ARABIDOPSISCabello, J. V. and Chan, R. L.Instituto de Agrobiotecnología del Litoral, CONICET/ UNL. Santa Fe, Argentina.E-mail: jcabello@fbcb.unl.edu.arTranscription factors (TFs) are key regulatory proteins in many plant stress responses.  We previously reported that a sunflower TF belonging to the HD-Zip subfamily I confers antifreeze tolerance to transgenic Arabidopsis plants. This survey reports the molecular mechanisms involved in such tolerance. A transcriptome analysis performed with these plants showed increased transcript levels of glucanases, chitinases, thaumatin-like and pathogenesis related proteins. Based on these and qRT-PCR results, we obtained novel transgenic plants overexpressing the Arabidopsis glucanase (At4g16260) and PR2 (At3g57260) encoding genes. Both genotypes exhibited a normal morphological phenotype in normal conditions, but were more tolerant than WT plants to freezing stress. The tolerance presented by plants expressing the glucanase was higher than in those which express PR2. Apoplastic extracts obtained from transgenic plants after 3 hours at -8 °C were almost twice concentrated in proteins than those obtained from WT plants and showed a differential pattern in SDS-PAGE  On the other hand; apoplastic proteins extracted from cold-acclimated plants expressing the sunflower TF were able to inhibit the recrystallization of iceWe propose that the cold tolerance conferred by the sunflower TF occurs  via the regulated action of the induced glucanase and PR proteins.