Chlorophyll biosynthesis and assembly into chlorophyll-protein complexes in isolated developing chloroplasts
Isolated developing plastids from greening cucumber cotyledons or from photoperiodically grown pea seedlings incorporated UC-labeled 5-aminolevulinic acid (ALA) into chlorophyll (Chl). Incorporation was light dependent, enhanced by S-adenosylmethionine, and linear for 1 hr. The in vitro rate of Chl synthesis from ALA was comparable to the in vivo rate of Chl accumulation. Levulinic acid and dioxoheptanoic acid strongly inhibited Chl synthesis but not plastid protein synthesis. Neither chloramphenicol nor spectinomycin affected Chl synthesis, although protein synthesis was strongly inhibited. Components of thylakoid membranes from plastids incubated with ( UC)ALA were resolved by electrophoresis and then subjected to autoradiography. This work showed that (i) newly synthesized Chl was assembled into Chl-protein complexes and (ii) the inhibition of protein synthesis during the incubation did not alter the labeling pattern. Thus, there was no observable short-term coregulation between Chl synthesis (from ALA) and the synthesis of membrane proteins in isolated plastids.
- Research Organization:
- Univ. of California, Davis, CA (United States)
- OSTI ID:
- 6335274
- Journal Information:
- Proc. Natl. Acad. Sci. U.S.A.; (United States), Vol. 82:16
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
CHLOROPHYLL
BIOSYNTHESIS
COMPLEXES
CHLOROPLASTS
AUTORADIOGRAPHY
ELECTROPHORESIS
PROTEINS
AMINOLEVULINIC ACID
CARBON 14 COMPOUNDS
CUCUMBERS
PHOTOSYNTHESIS
PISUM
AMINO ACIDS
BACTERIA
CARBOXYLIC ACIDS
CELL CONSTITUENTS
CHEMICAL REACTIONS
FOOD
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
LABELLED COMPOUNDS
LEGUMINOSAE
MICROORGANISMS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHYTOCHROMES
PIGMENTS
PLANTS
PORPHYRINS
RHIZOBIUM
SYNTHESIS
VEGETABLES
550301* - Cytology- Tracer Techniques
550201 - Biochemistry- Tracer Techniques