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Tuber-specific cytosolic expression of a bacterial phosphoglucomutase in potato (Solanum tuberosum L.) dramatically alters carbon partitioning.
- Source :
-
Plant & cell physiology [Plant Cell Physiol] 2005 Apr; Vol. 46 (4), pp. 588-97. Date of Electronic Publication: 2005 Feb 02. - Publication Year :
- 2005
-
Abstract
- Constitutive antisense inhibition of the cytosolic isoform of phosphoglucomutase in the potato (Solanum tuberosum L.) results in restriction of photosynthesis, growth inhibition and modified tuber morphology, and a severe restriction of tuber starch synthesis. Here we describe the consequences of the tuber-specific expression of an Escherichia coli phosphoglucomutase in the cytosol. Analysis of [14C]glucose metabolism by tuber discs isolated from wild type and transformants revealed that the rates of sucrose and starch synthesis were unaltered but that the rate of glycolysis was depressed in the transgenics. The transformant tubers also contained dramatically reduced amino acid content and significantly higher levels of ADP, but were characterized by elevated levels of Krebs cycle intermediates and an unaltered rate of respiration. In addition to these metabolic consequences of the overexpression of the E. coli enzyme, we observed morphological changes in tubers, with the transformants having a smaller number of larger tubers which exhibited delayed rates of sprouting with respect to the wild type. These results are discussed with respect to current models of the regulation of central plant metabolism and tuber dormancy.
- Subjects :
- Adenosine Monophosphate metabolism
Carbohydrate Metabolism
Carbon metabolism
Escherichia coli genetics
Gene Expression Regulation, Plant
Glucose metabolism
Glycolysis
Phenotype
Phosphoglucomutase metabolism
Phosphorylation
Plant Tubers growth & development
Plants, Genetically Modified
Solanum tuberosum growth & development
Starch metabolism
Sucrose metabolism
Transformation, Genetic
Uridine metabolism
Cytosol enzymology
Escherichia coli enzymology
Phosphoglucomutase genetics
Plant Tubers enzymology
Solanum tuberosum enzymology
Solanum tuberosum genetics
Subjects
Details
- Language :
- English
- ISSN :
- 0032-0781
- Volume :
- 46
- Issue :
- 4
- Database :
- MEDLINE
- Journal :
- Plant & cell physiology
- Publication Type :
- Academic Journal
- Accession number :
- 15695443
- Full Text :
- https://doi.org/10.1093/pcp/pci058