CEFOBI   05405
CENTRO DE ESTUDIOS FOTOSINTETICOS Y BIOQUIMICOS
Unidad Ejecutora - UE
artículos
Título:
Enhanced cytosolic NADP-ME2 activity in A. thaliana affects plant development, stress tolerance and specific diurnal and nocturnal cellular processes
Autor/es:
BADIA, M. B.; ARIAS, C. L.; TRONCONI, M. A.; MAURINO, V. G.; ANDREO, C. S.; DRINCOVICH, M. F.; GERRARD WHEELER, M. C.
Revista:
PLANT SCIENCE
Editorial:
ELSEVIER IRELAND LTD
Referencias:
Lugar: Amsterdam; Año: 2015 p. 193 - 203
ISSN:
0168-9452
Resumen:
Arabidopsis thaliana hasfour NADP-dependent malic enzymes (NADP-ME 1-4) for reversible malate decarboxylation,with NADP-ME2 being the only cytosolic isoform ubiquitously expressed and responsiblefor most of the total activity. In this work, we further investigated itsphysiological function by characterizing Arabidopsis plants over-expressingNADP-ME2 constitutively. In comparison to wild type, these plants exhibited reducedrosette and root sizes, delayed flowering time and increased sensitivity to mannitoland polyethylene glycol. The increased NADP-ME2 activity led to a decreasedexpression of other ME and malate dehydrogenase isoforms and generated a redoximbalance with opposite characteristics depending on the time point of the dayanalyzed. The over-expressing plants also presented a higher content of C4organic acids and sugars under normal growth conditions. However, theaccumulation of these metabolites in the over-expressing plants wassubstantially less pronounced after osmotic stress exposure compared to wild type.Also, a lower level ofseveral amino acids and osmoprotector compounds was observed in transgenicplants. Thus, the gain of NADP-ME2 expression has profound consequences in the modulationof primary metabolism in A. thaliana,which reflect the relevance of this enzyme and its substrates and products in planthomeostasis.