| dc.creator |
Leterrier, Marina |
|
| dc.creator |
Corpas, Francisco J. |
|
| dc.creator |
Barroso-Albarracín, Juan Bautista |
|
| dc.creator |
Sandalio, Luisa M. |
|
| dc.creator |
Río, Luis A. del |
|
| dc.date |
2008-04-01T07:34:47Z |
|
| dc.date |
2008-04-01T07:34:47Z |
|
| dc.date |
2005-08 |
|
| dc.date.accessioned |
2017-01-31T01:01:23Z |
|
| dc.date.available |
2017-01-31T01:01:23Z |
|
| dc.identifier |
Plant Physiology 138(4): 2111–2123 (2005) |
|
| dc.identifier |
1532-2548 |
|
| dc.identifier |
http://hdl.handle.net/10261/3396 |
|
| dc.identifier |
10.1104/pp.105.066225 |
|
| dc.identifier.uri |
http://dspace.mediu.edu.my:8181/xmlui/handle/10261/3396 |
|
| dc.description |
In plant cells, ascorbate is a major antioxidant that is involved in the ascorbate-glutathione cycle. Monodehydroascorbate
reductase (MDAR) is the enzymatic component of this cycle involved in the regeneration of reduced ascorbate. The
identification of the intron-exon organization and the promoter region of the pea (Pisum sativum) MDAR 1 gene was achieved
in pea leaves using the method of walking polymerase chain reaction on genomic DNA. The nuclear gene of MDAR
1 comprises nine exons and eight introns, giving a total length of 3,770 bp. The sequence of 544 bp upstream of the initiation
codon, which contains the promoter and 5# untranslated region, and 190 bp downstream of the stop codon were also
determined. The presence of different regulatory motifs in the promoter region of the gene might indicate distinct responses to
various conditions. The expression analysis in different plant organs by northern blots showed that fruits had the highest level
of MDAR. Confocal laser scanning microscopy analysis of pea leaves transformed with Agrobacterium tumefaciens having the
binary vectors pGD, which contain the autofluorescent proteins enhanced green fluorescent protein and enhanced yellow
fluorescent protein with the full-length cDNA for MDAR 1 and catalase, indicated that the MDAR 1 encoded the peroxisomal
isoform. The functional analysis of MDAR by activity and protein expression was studied in pea plants grown under eight
stress conditions, including continuous light, high light intensity, continuous dark, mechanical wounding, low and high
temperature, cadmium, and the herbicide 2,4-dichlorophenoxyacetic acid. This functional analysis is representative of all the
MDAR isoforms present in the different cell compartments. Results obtained showed a significant induction by high light
intensity and cadmium. On the other hand, expression studies, performed by semiquantitative reverse transcriptionpolymerase
chain reaction demonstrated differential expression patterns of peroxisomal MDAR 1 transcripts in pea plants
grown under the mentioned stress conditions. These findings show that the peroxisomal MDAR 1 has a differential regulation
that could be indicative of its specific function in peroxisomes. All these biochemical and molecular data represent a significant
step to understand the specific physiological role of each MDAR isoenzyme and its participation in the antioxidant
mechanisms of plant cells. |
|
| dc.description |
This work was supported by an Research Training Network
grant of the European Union (contract HPRN–CT–2000–00094) and
the Ministry of Science and Technology (projects AGL2003–05524
and BFI2002–04440–CO2–01). |
|
| dc.description |
Peer reviewed |
|
| dc.format |
448713 bytes |
|
| dc.format |
application/pdf |
|
| dc.language |
eng |
|
| dc.publisher |
American Society of Plant Physiologists |
|
| dc.relation |
http://dx.doi.org/10.1104/pp.105.066225 |
|
| dc.rights |
closedAccess |
|
| dc.title |
Peroxisomal Monodehydroascorbate Reductase. Genomic Clone Characterization and Functional Analysis under Environmental Stress Conditions |
|
| dc.type |
Artículo |
|