Abstract

The contamination of the irrigation waters with arsenic is a significant ecological problem. A study was undertaken to investigate the effect of arsenate and arsenite on photosynthesis and oxidative stress in rice (Oryza sativa L.). Arsenic was applied as Na2 HAS3 O4 and As2O3 at concentrations of 5, 10, 15 and 20 mg/1. The results showed that plastid pigment content and leaf gas-exchange decreased significantly with increase in the concentration of arsenic. The inhibitory effect of arsenite was more pronounced in reducing pigment content and gas exchange than arsenate contaminated plants. The increase in lipid peroxidation with decline in catalase activity in rice indicated a typical reaction of the plants to oxidative stress.