Phenols, ozone, and their involvement in pigmentation and physiology of plant injury
In plant cells, phenols and derivatives are located in chloroplasts and in vacuoles; enzymes that oxidize phenols are also located in chloroplasts and in cytoplasm but are maintained in separate compartments by membranes. Ozone impairs the integrity of cell membranes and thus permits oxidative enzymes to oxidize phenols to their respective quinones. o-Quinones have an E/sub 0/' of +1.9V and will polymerize with amino acids, amines and sulfhydryl groups of proteins to form low molecular weight reddish-brown pigments in leaves of ozone-treated plants. This involvement of phenols appears to be the cause of the visible necrotic lesions on injured leaves. The polymers are lignin- or tannin-like and as such detract from the esthetic and probably nutritional value of foliage from important food and feed crops. Concentrations of caffeoyl derivatives, caffeic and chlorogenic acids are increased in ozone-damaged tissues. Both o-diphenols increase O/sub 2/ consumption and reduce CO/sub 2/ fixation. Therefore, plant growth and quality could be reduced by ozone's (a) impairing membrane integrity which would promote cell degradation through reduction in synthesis of products of primary metabolism and by (b) increasing products of secondary metabolism. 48 references, 8 figures, 1 table.
- Research Organization:
- Dept. of Agriculture, Beltsville, MD
- OSTI ID:
- 5871610
- Report Number(s):
- CONF-740349-; TRN: 85-008131
- Journal Information:
- ACS Symp. Ser.; (United States), Vol. 3; Conference: 167. national meeting of the American Chemical Society, Los Angeles, CA, USA, 31 Mar 1974
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
OZONE
BIOLOGICAL EFFECTS
PHENOLS
METABOLISM
AIR POLLUTION
CELL MEMBRANES
DECOMPOSITION
ENZYME ACTIVITY
LEAVES
OXIDATION
PLANTS
ULTRASTRUCTURAL CHANGES
AROMATICS
CELL CONSTITUENTS
CHEMICAL REACTIONS
HYDROXY COMPOUNDS
MEMBRANES
MORPHOLOGICAL CHANGES
ORGANIC COMPOUNDS
POLLUTION
560303* - Chemicals Metabolism & Toxicology- Plants- (-1987)
560301 - Chemicals Metabolism & Toxicology- Cells- (-1987)