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Title: Cytochrome C oxidase activity in germinating Phaseolus vulgaris l. seeds: Effects of carbon monoxide

Cytochrome c oxidase is a key bioenergetic enzyme required for seed germination. The enzyme was isolated from 2-day germinating beans and biochemically compared to its bovine heart counterpart. Carbon monoxide, which binds to the heme a{sub 3} site of cytochrome c oxidase, we used to probe O{sub 2} utilization activity in isolated enzyme, mitochondrial particles, and whole seeds. Bean seeds under 80% CO/20% O{sub 2} exhibited 46% growth inhibition as determined by root length. Reversible, dose-dependent partial inhibition of bean seed mitochondrial respiration was observed in the presence of CO; heart mitochondria had a more sensitive, less reversible response. Effects of CO on bean and bovine heart enzyme were similar. The close correlation of CO effects observed on seedling growth, mitochondrial respiration and cytochrome oxidase activity indicate an important role for this enzyme during the early stages of seed germination.
Authors:
 [1] ; ;
  1. (Colorado State Univ., Fort Collins (USA))
Publication Date:
OSTI Identifier:
6604197
Resource Type:
Journal Article
Resource Relation:
Journal Name: Plant Physiology, Supplement; (USA); Journal Volume: 89:4
Country of Publication:
United States
Language:
English
Subject:
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.; CARBON MONOXIDE; TOXICITY; MIXED-FUNCTION OXIDASES; ENZYME ACTIVITY; SEEDS; GERMINATION; CATTLE; DOSE-RESPONSE RELATIONSHIPS; HEART; MITOCHONDRIA; PHASEOLUS; SPROUT INHIBITION; ANIMALS; BODY; CARBON COMPOUNDS; CARBON OXIDES; CARDIOVASCULAR SYSTEM; CELL CONSTITUENTS; CHALCOGENIDES; DOMESTIC ANIMALS; ENZYMES; INHIBITION; LEGUMINOSAE; MAGNOLIOPHYTA; MAGNOLIOPSIDA; MAMMALS; ORGANOIDS; ORGANS; OXIDES; OXIDOREDUCTASES; OXYGEN COMPOUNDS; OXYGENASES; PLANTS; RUMINANTS; VERTEBRATES 560300* -- Chemicals Metabolism & Toxicology