Plant resistance mechanisms to air pollutants: rhythms in ascorbic acid production during growth under ozone stress

Journal Article · Tue Jan 01 00:00:00 EST 1991 · Chronobiology International; (United States)

DOI:https://doi.org/10.3109/07420529109059161· OSTI ID:5449038

Lee, E H ^[1]

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1. Climate Stress Laboratory, USDA, ARS, Beltsville, MD (United States)

Relationships between ozone (O3) tolerance and leaf ascorbic acid concentrations in O3-susceptible (O3-S) 'Hark' and O3-resistant (O3-R) 'Hood' soybean, Glycine max (L.) Merr., cultivars were examined with high-performance liquid chromatography (HPLC). Leaf samples were analyzed at 4 intervals during a 24 h period. Soybean cultivars grown in the greenhouse with charcoal filtered (CF) and nonfiltered (NF) air showed daily oscillations in ascorbic acid production. Highest ascorbic acid levels in leaves during light coincided with highest concentrations of photochemical oxidants in the atmosphere at 2:00 p.m. The resistant genotype produced more ascorbic acid in its trifoliate leaves than did the corresponding susceptible genotype. Under CF air (an O3-reduced environment) O3-S and O3-R cultivars showed rhythms in ascorbic acid production. In NF air (an O3 stress environment) the O3-R cultivar alone showed rhythms in ascorbic acid production. Results indicated that superior O3 tolerance in the Hood soybean cultivar (compared with Hark) was associated with a greater increase in endogenous levels of ascorbic acid. Ascorbic acid may scavenge free radicals and thereby protect cells from injury by O3 or other oxyradical products. Plants defend themselves against photochemical oxidant stress, such as O3, by several mechanisms. Experimental evidence indicates that antioxidant defense systems existing in plant tissues may function to protect cellular components from deleterious effects of photochemical oxidants through endogenous and exogenous controls.

• OSTI ID: 5449038
• Journal Information: Chronobiology International; (United States), Vol. 8:2
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ASCORBIC ACID
BIOSYNTHESIS
GLYCINE HISPIDA
TOLERANCE
OZONE
TOXICITY
AIR POLLUTION
BIOLOGICAL STRESS
GENOTYPE
LEAVES
PLANT GROWTH
RADICALS
GROWTH
LEGUMINOSAE
MAGNOLIOPHYTA
MAGNOLIOPSIDA
PLANTS
POLLUTION
SYNTHESIS
VITAMINS
560300* - Chemicals Metabolism & Toxicology