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b-Type Cytochromes in Higher Plant Plasma Membranes
H Asard1, M Venken, R Caubergs
1Department of General Botany, University of Antwerp (RUCA), B-2020, Antwerp, Belgium.
Plant Physiology
|July 1, 1989
Summary
Researchers identified multiple b-type cytochromes in plant plasma membranes. These cytochromes vary by species and may play a role in blue light perception.
Area of Science:
- Plant molecular biology
- Biochemistry
- Cell biology
Background:
- Plasma membranes in higher plants contain various cytochrome species.
- Understanding these cytochromes is crucial for elucidating plant physiological processes.
Purpose of the Study:
- To investigate the composition and characteristics of b-type cytochromes in higher plant plasma membranes.
- To identify and differentiate cytochrome species based on spectral and redox properties.
Main Methods:
- Purification of b-type cytochromes using aqueous two-phase partitioning.
- Characterization of cytochromes by wavelength maxima and redox midpoint potentials (E(0)').
Main Results:
- At least three distinct b-type cytochromes were identified.
- Cytochrome b-560.7 was found in zucchini and bean plasma membranes, with varying concentrations.
- Cauliflower inflorescences contained cytochrome b-558.8, likely functionally similar to b-560.7.
- Plasma membranes typically host two to three cytochrome species, with species-dependent occurrence and concentrations.
- A high-potential cytochrome, reducible by ascorbate but not NADH, was observed.
Conclusions:
- The study characterized multiple b-type cytochromes in plant plasma membranes.
- Cytochrome composition and concentration are species-specific.
- The identified high-potential cytochrome may be involved in blue light perception in plants.
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