INVESTIGADORES
WELCHEN Elina
artículos
Título:
The promoters of Arabidopsis thaliana genes AtCOX17-1 and -2, encoding a cooper chaperone involved in cytochrome c oxidase biogenesis, are preferentially active in roots and anthers and induced by biotic and abiotic stress.
Autor/es:
ATTALLAH, CV., WELCHEN, E. AND GONZALEZ, DH.
Revista:
PHYSIOLOGIA PLANTARUM
Referencias:
Año: 2007 vol. 129 p. 123 - 134
ISSN:
0031-9317
Resumen:
AtCOX17 genes encode Arabidopsis thaliana homologs of the yeast metallochaperone
Cox17p, involved in the delivery of copper for cytochrome c
oxidase (COX) assembly. Two different AtCOX17 genes, located in chromosomes
1 and 3, are present in the Arabidopsis genome. Sequences available
in data banks indicate that the presence of two genes is a common feature
in monocots, but not in dicots, suggesting that Arabidopsis genes may be the
result of a recent duplication. Sequences upstream from the translation start
sites of AtCOX17 genes, which include an intron located in the 5# leader
region, were introduced into plants in front of the gus gene. For both genes,
expression was localized preferentially in young roots and anthers, but almost
10-fold higher b-glucuronidase activity levels were observed in plants
transformed with AtCOX17-1 upstream regions. Both promoters were induced
to different extents by wounding, treatment of leaves with the bacterial
pathogen Pseudomonas syringae and incubation with agents that produce
oxidative stress and metals. AtCOX17-2 showed similar responses to these
factors, while AtCOX17-1 was more strongly induced by relatively low
(10100 mM) copper. The results indicate that both AtCOX17 genes have
similar, though not identical, expression characteristics and suggest the
existence in their promoters of elements involved in tissue-specific expression
and in responses to factors that may produce mitochondrial or cell damage.
It can be speculated that Arabidopsis COX17 accumulates under stress
conditions to actively replace damaged or inactive cytochrome c oxidase to
sustain cyanide-sensitive respiration in plant cells.