Abstract

GALATRO, Andrea; ROUSSEAU, Ivan  and  PUNTARULO, Susana. Concentration analysis in steay-state of ascorbate radical in soybean seedlings determined by electronic paramagnetic resonancy. Phyton (B. Aires) [online]. 2006, vol.75, pp.7-20. ISSN 1851-5657.

Electron Paramagnetic Resonance (EPR) has been developed as a versatile field that uses different techniques sharing the common feature of resonant microwave radiation absorption by paramagnetic substances. Certain free radicals, such as ascorbyl radical (A•), show an stable spectrum, and can be directly detected by EPR at room temperature. Studies included in this work clearly show that this highly sensitive methodology can be successfully applied to biological systems. Exposure of plants to UV-B radiation was studied as a factor of oxidative stress in plants, and the effect on A• steady state concentration was analyzed. A kinetic analysis was performed considering a simple physical chemistry mechanism, which allowed the estimation of A• steady state concentration that properly parallels experimental values obtained by EPR.

Keywords : Ascorbate radical; EPR; UV-B radiation; Oxidative stress.

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