Antioxidant responses in rice seedlings under conditions of etiolation and de-etiolation
2002
Banerjee, S.N. (University of Calcutta, Calcutta (India). Dept. of Biochemistry) | Pal, S.K. | Chakrabarti, K. (University College of Agriculture, Calcutta (Indai). Dept. of Plant Physiology))
Components of the antioxidant defense system in the leaves of etiolated rice seedlings were compared to that of light-grown (control) seedlings. The activities of ascorbate peroxidase and peroxidase showed remarkable increase in etiolated seedlings as compared to control, which could not be explained in terms of a decrease in soluble protein content. The activity of superoxide dismutase also increased. Initial increase in the activity of catalase was reversed later. The increase of antioxidative enzymes was indicative of a pro-oxidant signal under a non-photosynthetic condition. Among the non-enzymic antioxidants, ascorbate was decreased in etiolated seedlings, while glutathione was similar in control and etiolated seedlings. Gradual accumulation of chlorophyll pigments during de-etiolation in etiolated leaves was accompanied with a steady normalization (with respect to control) in the antioxidants. This was suggestive of an important quenching role of cholorophyll in an illuminated environment.
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