CEFOBI   05405
CENTRO DE ESTUDIOS FOTOSINTETICOS Y BIOQUIMICOS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Loss of function of NADP-malic enzyme 1 results in lower sensitivity to aluminium
Autor/es:
BADIA, MARIANA; MARIEL GERRARD WHEELER; ANDREO, CARLOS S; MARIA FABIANA DRINCOVICH
Reunión:
Congreso; XII Panamerican Association for Biochemistry and Molecular Biology (PABMB) Congress; 2013
Resumen:
In acidic soils,
aluminum (Al) toxic species are solubilized causing root growth inhibition.
The release of organic acids that chelate these ions plays a central role in
plant Al tolerance. In A. thaliana,
malate is the organic acid excreted to a greater extent. It has been
demonstrated the importance of malate channels in this mechanism, but little
is known about the metabolic changes underlying excretion. To determine if
malic enzyme (ME), which catalyzes the oxidative decarboxylation of malate
might be involved in this process, Arabidopsis
mutant lines of each gene of the ME family were analyzed in response to Al.
Plants lacking NADP-ME1 presented lower inhibition of root elongation and an
increase in root malate levels after Al treatment. This increased tolerance
was not seen in mutants of the other isoforms and could be related to the
particular and confined localization of this protein in roots. Moreover,
quantification of transcript levels showed a specific decrease in the
expression of nadp-me1 in wild type seedlings exposed to Al. Thus, NADP-ME1
could be involved in regulating the levels of malate in the cytosol of the
root apex and it loss may result in an increase in the content of this
organic acid being available for excretion. Additionally, this isoform may be
affecting the levels of signaling molecules of Al stress such as ROS or
aminoacids