Reduced enzyme activity and starch level in an induced mutant of chloroplast phosphoglucose isomerase
Ethyl methane sulfonate treatment was used to induce a mutation in the nuclear gene encoding the chloroplast isozyme of phosphoglucose isomerase in Clarkia xantiana. The mutation, which proved allelic to wild type activity, was backcrossed to wild type for five generations so that the two could be compared in a near isogenic background. An immunological analysis showed that the mutant, when homozygous, reduced the activity of the isozyme by about 50%. In contrast to wild type, the mutant showed little change in leaf starch level over a diurnal period or following a 72-hour continuous light treatment. By the end of the diurnal light period, the mutant accumulated only about 60% as much starch as wild type. However, mutant leaves had an increased sucrose level presumably because photosynthate was directly exported from the chloroplasts. The mutant also exhibited reduced leaf weight. These changes in metabolism and growth suggest that the wild type level of plastid phosphoglucose isomerase activity is necessary to achieve wild type carbohydrate status.
- Research Organization:
- Welsh Plant Breeding Station, Aberystwyth
- OSTI ID:
- 6989380
- Journal Information:
- Plant Physiol.; (United States), Journal Name: Plant Physiol.; (United States) Vol. 81:2; ISSN PLPHA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
CARBOHYDRATES
CHEMICAL REACTIONS
DATA
EMS
ENZYME ACTIVITY
ENZYMES
ESTERS
EXPERIMENTAL DATA
GROWTH
INFORMATION
ISOENZYMES
METABOLISM
MUTAGENESIS
MUTAGENS
MUTANTS
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
OXIDOREDUCTASES
PHOTOCHEMICAL REACTIONS
PHOTOSYNTHESIS
PLANT GROWTH
PLANTS
POLYSACCHARIDES
REAGENTS
SACCHARIDES
SEEDS
STARCH
SULFONIC ACID ESTERS
SYNTHESIS