Phytochrome chromophore biosynthesis. [Avena sativa]
Etiolated Avena sativa L. seedlings grown in the presence of gabaculine (5-amino-1,3-cyclohexadienylcarboxylic acid) contained reduced levels of phytochrome as shown by spectrophotometric and immunochemical assays. Photochromic phytochrome levels in gabaculine-grown plants were estimated to be 20% of control plants, while immunoblot analysis showed that the phytochrome protein moiety was present at approximately 50% of control levels. Gabaculine-grown seedlings administered either 5-aminolevulinic acid or biliverdin exhibited a rapid increase of spectrophotometrically detectable phytochrome. Phytochrome concentrations estimated immunochemically did not similarly increase throughout treatment with either compound. Similar experiments with 5-amino(4-/sup 14/C) levulinic acid showed radiolabeling of phytochrome with kinetics that paralleled the spectrally detected increase. These results are consistent with (a) the intermediacy of both 5-aminolevulinic acid and biliverdin in the biosynthetic pathway of the phytochrome chromophore and (b) the lack of coordinate regulation of chromophore and apoprotein synthesis in Ayena seedlings.
- Research Organization:
- Univ. of California, Davis
- OSTI ID:
- 5900517
- Journal Information:
- Plant Physiol.; (United States), Journal Name: Plant Physiol.; (United States) Vol. 84:2; ISSN PLPHA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
59 BASIC BIOLOGICAL SCIENCES
ANABOLISM
BIOSYNTHESIS
CARBON 14 COMPOUNDS
CARBOXYLIC ACIDS
CEREALS
CHEMICAL REACTIONS
ENZYME INHIBITORS
GRASS
GROWTH
ISOTOPE APPLICATIONS
KETO ACIDS
LABELLED COMPOUNDS
LEVULINIC ACID
METABOLISM
OATS
ORGANIC ACIDS
ORGANIC COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHYSIOLOGY
PHYTOCHROMES
PIGMENTS
PLANT GROWTH
PLANTS
PRECURSOR
PROTEINS
SPECTROPHOTOMETRY
SYNTHESIS
TRACER TECHNIQUES