INVESTIGADORES
GOMEZ CASATI Diego Fabian
congresos y reuniones científicas
Título:
Structural alteration of plant cell wall in transgenic Arabidopsis thaliana
Autor/es:
BUSI, M. V.; PERALTA, DA; GRISOLIA, M.; VALDEZ, H.; DIEGO FABIAN GOMEZ CASATI
Lugar:
}puerto Madryn
Reunión:
Congreso; XLVI Reunion SAIB; 2010
Resumen:
Carbohydrate-binding
modules (CBM) are non-catalytic domains, clasified in 59 families, which are
found being part of non-catalytic proteins, transport proteins and enzymes
involved in polysaccharide metabolism (i.e. the dynamic plant cell wall
metabolism). The SBD123 (Starch Binding
Domain) from the N-term region of starch synthase III from A. thaliana was classified into the CBM53
family and this was the first CBM described in a biosynthetic enzyme. In vitro adsorption assays show that
SBD123 has a promiscuous binding to starch and to other plant cell wall polysaccharides
such as xylane, pectin and cellulose. Considering
the evolutionary advantage of SBDs to posses two binding sites in regard to the
rest of the CBMs, we decided to evaluate this behavior in vivo. Thus, we carried out the expression of de SBD123 protein
targeted to the plant cell wall by the transformation of A. thaliana plants with a chimeric construct of the signal peptide
of Expansin 8 from A. thaliana fused
to SBD123. Transgenic plants phenotype was evaluated by transcriptomic,
metabolomic and fluorescence confocal microscopy. We found a decrease of cell wall polysaccharide content with alterations
in cell wall integrity, decrease of xylose and galactose (hemicellulose compounds)
and increased mRNA levels for CESA 4, 7, 8 (involved in secondary cell wall
synthesis) compared to wild type plants.