Abstract
The relationship between foliar ozone (O 3) tolerance and leaf ascorbic acid (AA) concentrations in O 3-susceptible (O 3-S) and O 3-resistant (O 3-R) cultivars of soybean ( Glycine max L.) cv. ‘Hark’ (O 3-S) and ‘Hood’ (O 3-R), and in snapbean ( Phaseolus vulgaris L.) cv. ‘BBL-290’ (O 3-S) and ‘Astro’ (O 3-R) was examined by use of high-performance liquid chromatography (HPLC). Isocratic separation of AA for leaf tissues was accomplished in < 5 min on a μBondapak C-8 reverse phase column using 2% NH 4H 2PO 4 (pH 2.8) as the solvent. Tissues were wxtracted with 6% metaphosphoric acid containing 1 × 10 −6 M EDTA. Results showed that resistant genotypes contained more AA in their trifoliate leaves than did the correspnding susceptible genotypes. Young trifoliate leaves were highly tolerant to O 3 and had proportionally higher AA concentrations than newly expanded leaves. A threshold concentration of approximately 1000 μg AA/g leaf fresh weight was required for good O 3 protection. Ascorbic acid is an antioxidant and is a free radical scavenger which at physiological levels can protect against lipid peroxidation and leaf damage. Ozone stress was shown to induce the production and accumulation of AA in O 3-treated leaves. Possible mechanisms for enhanced tolerance to O 3 stress are discussed.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
