Increased 8-hydroxyguanine content of chloroplast DNA from ozone-treated plants
The mechanism of ozone-mediated plant injury is not known but has been postulated to involve oxygen free radicals. Hydroxyl free radicals react with DNA causing formation of many products, one of which is 8-hydroxyguanine. By using high performance liquid chromatography with electrochemical detection, the 8-hydroxy-2'-deoxyguanosine (8-OHdG) content of a DNA enzymatic digest can be sensitively quantitated. Beans and peas were treated with an ozone regime that caused acute injury. Chloroplast DNA was obtained from plants harvested either immediately after ozone treatment or 24 hours later. Ozone-exposed plants in general had nearly two-fold higher levels of 8-OHdG as compared to control plants. In vitro treatment of DNA in buffer solution with ozone did not cause formation of 8-OHdG in DNA, even though ozone did react directly with the macromolecule per se. Exposure of isolated illuminated chloroplasts to ozone caused nearly a seven-fold increase in the amount of 8-OHdG in the chloroplast DNA as compared to none-oxone-exposed chloroplasts. The results suggest that ozone exposure to plants causes formation of enhanced levels of oxygen free radicals, thus mediating formation of 8-OHdG in chloroplast DNA. The reaction of ozone with DNA per se did not cause formation of 8-OHdG.
- Research Organization:
- Oklahoma Medical Research Foundation, Oklahoma City, OK (USA)
- OSTI ID:
- 7190069
- Report Number(s):
- PB-90-198664/XAB
- Resource Relation:
- Other Information: Pub. in Plant Physiology 91, 644-647(1989)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
OZONE
TOXICITY
PHASEOLUS
SENSITIVITY
PISUM
AIR POLLUTION
CHLOROPLASTS
DNA
GUANINE
GUANOSINE
LIQUID COLUMN CHROMATOGRAPHY
RADICALS
AMINES
AROMATICS
AZAARENES
CELL CONSTITUENTS
CHROMATOGRAPHY
HETEROCYCLIC COMPOUNDS
HYDROXY COMPOUNDS
LEGUMINOSAE
MAGNOLIOPHYTA
MAGNOLIOPSIDA
NUCLEIC ACIDS
NUCLEOSIDES
NUCLEOTIDES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PLANTS
POLLUTION
PURINES
RIBOSIDES
SEPARATION PROCESSES
560300* - Chemicals Metabolism & Toxicology