INVESTIGADORES
GONZALEZ Daniel Hector
artículos
Título:
Metabolic regulation of genes encoding cytochrome c and cytochrome c oxidase subunit Vb in Arabidopsis
Autor/es:
WELCHEN, ELINA; CHAN, RAQUEL L.; GONZALEZ, DANIEL H.
Revista:
PLANT, CELL AND ENVIRONMENT (PRINT)
Editorial:
WILEY-BLACKWELL PUBLISHING, INC
Referencias:
Año: 2002 vol. 25 p. 1605 - 1615
ISSN:
0140-7791
Resumen:
In this study an analysis of the
expression of four Arabidopsis nuclear genes encoding components of the
mitochondrial cyanide-sensitive respiratory pathway: two genes encoding
cytochrome c oxidase subunit Vb (COX5b) and two genes encoding
cytochrome c (Cytc), was carried out. Northern blot analysis indicated
that these genes are expressed in several organs. Incubation of plants
in solutions containing metabolizable sugars produced an increase in
transcript levels. The effect of carbohydrates showed the same time and
concentration dependence for the four genes, suggesting the operation of
a common regulatory mechanism. Light produced an increase in transcript
levels, although smaller than that produced by sugars. Incubation of
plants in solutions with different nitrogen sources also produced
changes in expression. In the presence of ammonium, higher transcript
levels were observed with respect to plants treated with either
nitrogen-free or nitrate solutions. Nitrate, on the other hand, produced
a slight decrease in transcript levels and abolished the inducing
effect of ammonium. Reporter enzyme activity in transgenic plants
carrying a fusion of a Cytc gene promoter with the beta-glucuronidase
coding region was increased by the inclusion of sucrose and ammonium in
the culture medium. The present results suggest that carbon and nitrogen
metabolites act in concert to regulate the expression of different
components of the cyanide-sensitive respiratory pathway.