Pyruvate orthophosphate dikinase gene expression in developing wheat seeds
The amount of pyruvate orthophosphate dikinase (PPDK) (EC 2.7.9.1) protein in wheat (Triticum aestivum L. var Cheyenne) grains was determined at different stages of development by the protein blot method. The variation in PPDK protein with time in developing wheat grains was similar to that of the enzyme's activity reported by Meyer et al. The variation in levels of PPDK mRNA with seed development was determined by analysis of polypeptides immunoprecipitated by anti-PPDK serum from in vitro translation products of extracted seed RNA. This mRNA variation was similar to that of the in vivo enzyme levels and the correlation is consistent with the regulation of PPDK gene expression by the level of its mRNA. The highest level of PPDK in developing wheat seeds occurs later than the highest levels of both ribulose bisphosphate carboxylase and of chlorophyll, which are located in the green pericarp tissue. PPDK was located in both endosperm and pericarp tissue of the seeds. The tissue location and development profile of seed PPDK are consistent with a metabolic role of providing phosphoenolpyruvate as a substrate for recapturing respiratory CO/sub 2/ in the seed, and possibly for amino acid interconversion during development.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- DOE Contract Number:
- AC03-76SF00098
- OSTI ID:
- 5975787
- Journal Information:
- Plant Physiol.; (United States), Vol. 75:2
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
PHOSPHOTRANSFERASES
ENZYME ACTIVITY
WHEAT
METABOLISM
CARBOXYLASE
CHLOROPHYLL
GENES
MESSENGER-RNA
PLANT TISSUES
PROTEINS
RNA
SEEDS
BODY
CARBOXYLIC ACIDS
CEREALS
ENZYMES
GRASS
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
LIGASES
NUCLEIC ACIDS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHOSPHORUS-GROUP TRANSFERASES
PHYTOCHROMES
PIGMENTS
PLANTS
PORPHYRINS
TISSUES
TRANSFERASES
550200* - Biochemistry