INVESTIGADORES
CABELLO Julieta Virginia
congresos y reuniones científicas
Título:
GLUCANASE PROTEINS ARE INVOLVED IN FREEZING STRESS TOLERANCE IN ARABIDOPSIS
Autor/es:
CABELLO, J. V. AND CHAN, R. L.
Lugar:
San Miguel de Tucumán
Reunión:
Congreso; Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB); 2009
Resumen:
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Transcription 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 freezing 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 proteins extracted from
cold-acclimated plants expressing the sunflower TF were able to inhibit the
recrystallization of ice. On the other hand, apoplastic proteins extracted
from transgenic and WT plants induced 3 hours at -8 °C show a differential
pattern in SDS-PAGE and the total protein concentration were almost twice in
transgenic plants than in WT ones.
We propose that this TF confers cold tolerance to Arabidopsis plants via the induction of
glucanase proteins.
