INVESTIGADORES
IGLESIAS Alberto Alvaro
artículos
Título:
Characterization of Arabidopsis thaliana lines deficient in GAPC-1, a cytosolic NAD-dependent glyceraldehyde 3-phosphate dehydrogenase
Autor/es:
S.P. RIUS, P. CASATI, A.A. IGLESIAS, D.F. GOMEZ-CASATI
Revista:
PLANT PHYSIOLOGY.
Editorial:
American Society of Plant Biologists
Referencias:
Año: 2008 vol. 148 p. 1655 - 1667
ISSN:
0032-0889
Resumen:
Phosphorylating glyceraldehyde-3-P dehydrogenase (GAPC-1) is a highly conserved cytosolic enzyme that catalyzes theconversion of glyceraldehyde-3-P to 1,3-bis-phosphoglycerate; besides its participation in glycolysis, it is thought to beinvolved in additional cellular functions. To reach an integrative view on the many roles played by this enzyme, wecharacterized a homozygous gapc-1 null mutant and an as-GAPC1 line of Arabidopsis (Arabidopsis thaliana). Both mutant plantlines show a delay in growth, morphological alterations in siliques, and low seed number. Embryo development was altered,showing abortions and empty embryonic sacs in basal and apical siliques, respectively. The gapc-1 line shows a decrease in ATPlevels and reduced respiratory rate. Furthermore, both lines exhibit a decrease in the expression and activity of aconitase andsuccinate dehydrogenase and reduced levels of pyruvate and several Krebs cycle intermediates, as well as increased reactiveoxygen species levels. Transcriptome analysis of the gapc-1 mutants unveils a differential accumulation of transcripts encodingfor enzymes involved in carbon partitioning. According to these studies, some enzymes involved in carbon flux decreased(phosphoenolpyruvate carboxylase, NAD-malic enzyme, glucose-6-P dehydrogenase) or increased (NAD-malate dehydrogenase)their activities compared to the wild-type line. Taken together, our data indicate that a deficiency in the cytosolic GAPCactivity results in modifications of carbon flux and mitochondrial dysfunction, leading to an alteration of plant and embryodevelopment with decreased number of seeds, indicating that GAPC-1 is essential for normal fertility in Arabidopsis plants.