Effect of varying concentrations of caffeine and ascorbic acid on the radiosensitivity of barley seed irradiated in oxygenated or oxygen-free hydration medium at 25 and 37°C

• Published in: Environmental and experimental botany Vol. 17; no. 2; pp. 129 - 133
• Main Authors: Javed Afzal, S.M., Kesavan, P.C.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 1977
• ISSN: 0098-8472; 1873-7307
• DOI: 10.1016/0098-8472(77)90006-5

The modification of radiosensitivity of barley seed with 1.75 × 10 −3 M and 3.8 × 10 −3 M concentrations of caffeine and ascorbic acid during irradiation in oxygenated and oxygen-free hydration medium was studied at 25 and 37°C, respectively. Both concentrations of caffeine and ascorbic acid afford protection against oxic radiation damage which is maximal at 25°C. Caffeine effectively potentiates the anoxic component of damage but ascorbic acid has no influence at all. at 25°C there is no concentration-dependent effect of caffeine or ascorbic acid. At 37°C, there is no effect, whatsoever, of either concentration of ascorbic acid, whereas caffeine dramatically potentiates the radiaiton damage under both oxygenated and oxygen-free conditions, and the magnitude of potentiation is concentration-dependent. The possible reactivity of caffeine and ascorbic acid towards the precursors of oxygen-dependent and -independent components of damage in determining the mode and magnitudes of modification is discussed briefly.