Characteristics of physiological and biochemical responses of soybean cultivars to short term ozone exposures
- Virginia Polytechnic Institute and State Univ., Blacksburg (USA)
The differential sensitivity to ozone based on the degree of visible injury among soybean (Glycine max (L.) Merr.) cvs: Dare (O{sub 3}-sensitive), Williams and Essex was investigated. Gas exchange measurements using a portable Li-Cor 6200 Photosynthesis System revealed that cv Essex maintained a higher net photosynthetic rate (Pn) than cvs Williams and Dare during a 4 hr fumigation with 0.2 {mu}l l{sup {minus}1} O{sub 3}. However, cv Dare had a higher stomatal conductance (Cs) than the other cvs during the exposure period suggesting a higher O{sub 3} influx into the leaf tissues. The maximum reductions in Pn and Cs of all cvs by O{sub 3} were approximately 30% and 70%, respectively. The antioxidant system, consisting of the metabolites: glutathione (GSH and GSSG) and ascorbic acid (AA and dHAA), and the enzymes: glutathione reductase (GRase), ascorbate peroxidase (APase) and superoxide dismutase (SOD), was found to be different in the endogenous levels or activities among cvs. There were no significant changes caused by O{sub 3} exposure, however, trends in metabolite concentrations and enzyme activities were evident. Most notably, O{sub 3} resulted in decreases of dHAA in cvs Dare and Williams, AA in cv Essex and GSSG in cv Williams and increases of GSSG in cv Essex, AA in cvs Dare and Williams and SOD in cv Dare.
- OSTI ID:
- 5628876
- Report Number(s):
- CONF-9007196--
- Journal Information:
- Plant Physiology, Supplement; (USA), Journal Name: Plant Physiology, Supplement; (USA) Vol. 93:1; ISSN PPYSA; ISSN 0079-2241
- Country of Publication:
- United States
- Language:
- English
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