Relationship between 5S and 20S forms of malate synthase in maturing cottonseeds
Malate synthase (MS) activity appears and increases during seed maturation persists during desiccation, then increases again following germination. Because different modes of synthesis and organelle import of MS may occur in maturing and germinated seeds, a comparative study was performed. A comparison of immunoprecipitations from in-vivo-labeled seeds (/sup 35/S-met) and in-vitro translations of Poly A+ RNA (wheat germ) showed no detectable differences in subunit mol wt. When MS activity first appears (42 DPA) only the cytosolic 5S form is found in rate-zonal gradients (5-25% sucrose). At 48 DPA, O d, and 48 h germinated seeds both the 5S and glyoxysomal 20S forms are present, with the 20S becoming more prevalent. Western blots of SDS-PAGE gels showed that no other form(s) of MS (inactive) are present in rate-zonal fractions. Calculations of radiospecific activity (per MS activity) of 5S and 20S forms radiolabeled in vivo (/sup 35/S-met) at various time periods provided further convincing evidence that there is a 5S precursor to 20S product relationship during both seed maturation and seedling growth.
- Research Organization:
- Arizona State Univ., Tempe
- OSTI ID:
- 5903871
- Report Number(s):
- CONF-8707108-; TRN: 87-037217
- Journal Information:
- Plant Physiol., Suppl.; (United States), Vol. 83:4; Conference: Annual meeting of the American Society of Plant Physiologists, St. Louis, MO, USA, 19 Jul 1987
- Country of Publication:
- United States
- Language:
- English
Similar Records
Malate synthase a membrane protein
Developmental biochemistry of cottonseed embryogenesis and germination. XIII. Regulation of biosynthesis of principal storage proteins
Related Subjects
LIGASES
BIOSYNTHESIS
MOLECULAR WEIGHT
PRECURSOR
SEEDS
ENZYME ACTIVITY
CENTRIFUGATION
COTTON PLANTS
ELECTROPHORESIS
GERMINATION
HYBRIDIZATION
IMMUNOASSAY
LABELLED COMPOUNDS
METHIONINE
ORGANOIDS
PLANT GROWTH
RNA
SEDIMENTATION
SEEDLINGS
SULFUR 35
TRACER TECHNIQUES
TRANSLOCATION
WHEAT
AMINO ACIDS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CARBOXYLIC ACIDS
CELL CONSTITUENTS
CEREALS
DAYS LIVING RADIOISOTOPES
DRUGS
ENZYMES
EVEN-ODD NUCLEI
GRASS
GROWTH
ISOTOPE APPLICATIONS
ISOTOPES
LIGHT NUCLEI
LIPOTROPIC FACTORS
NUCLEI
NUCLEIC ACIDS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
PLANTS
RADIOISOTOPES
SEPARATION PROCESSES
SULFUR ISOTOPES
SYNTHESIS
550201* - Biochemistry- Tracer Techniques