Abstract

Light-induced monodehydroascorbate (MDA) radical production was not detectable by EPR spectroscopy in untreated broad bean leaves, but it was observed after exposing the leaves to UV-B (280-320 nm) irradiation. After this pre-treatment, a low level of MDA radicals was also detectable without illumination. Light-induced MDA, MDA production in the dark, oxygen evolution, quantum yield of PSII as measured by Chi fluorescence, MDA producing and reducing enzyme activities were determined and compared in leaves after irradiation with various doses of UVB. Our results suggest that UV-B irradiation disturbs the balance of MDA radical production and reduction, resulting in increased light induced MDA signal. The enhancement of ascorbate photooxidation at the UV-B damaged donor side of PSII appears as a major factor in this process.

Full Text
Paper version not known

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 call

Disclaimer: 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.