CEFOBI   05405
CENTRO DE ESTUDIOS FOTOSINTETICOS Y BIOQUIMICOS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Gain of cytosolic NADP-ME activity impacts on primary metabolism and stress tolerance of A. thaliana
Autor/es:
BADIA, M. B.; ARIAS, C. L.; TRONCONI, M. A.; MAURINO, V. G.; ANDREO, C. S.; DRINCOVICH, M. F.; GERRARD WHEELER, M. C.
Lugar:
Mendoza
Reunión:
Congreso; XLVIII Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2012
Institución organizadora:
Sociedad Argentina de Investigación en Bioquímica y Biología Molecular
Resumen:
NAD(P)-malic enzyme (ME) catalyzes the
reversible oxidative decarboxylation of malate to pyruvate, CO2 and
NAD(P)H and is present as a multigene family in Arabidopsis thaliana. Phenotypic and
molecular characterization of plants over-expressing cytosolic NADP-ME2 was
carried out. These plants exhibited lower rosette weight and root length
relative to wild-type, added to an increased sensitivity to mannitol treatment on MS-plates or irrigation with PEG on
soil-grown plants. Interestingly, the increased NADP-ME
activity led to a decreased expression of the others constitutive ME isoforms
and of another malate metabolism related enzyme, the malate dehydrogenase. In
addition, this line presented higher content of organic acids and sugars
relative to wild-type under typical growth conditions.
However, the accumulation of these metabolites was substantially less
pronounced after osmotic stress exposure. This
indicates that altering malate metabolism by raising NADP-ME2 activity has
profound consequences for the response of the entire primary metabolism upon normal
and stress conditions. Overall, the gain of NADP-ME activity
produces changes in gene expression, enzymatic activities and metabolite levels
which reflect the relevance of this enzyme in the organic acid plant
metabolism.