Photosynthetic efficiency, ion analysis and carbohydrate metabolism in Brassica juncea Plants under cadmium stress

Abstract

Measurements of photosynthetic efficiency of Brassica juncea plants were made after subjecting them to cadmium (Cd) stress. Seeds were treated with 0.2, 0.4 and 0.6mM concentration of Cd. Observations were made on elemental analysis (Na+ & K+ ions and carbon, hydrogen, nitrogen and sulphur content), Cd accumulation, level of photosynthetic pigments (chlorophylls, carotenoids, anthocyanins, xanthophylls and flavonoid), gaseous exchange parameters (photosynthetic rate, stomatal conductance, transpiration rate, vapour pressure deficit, intrinsic mesophyll rate, water use efficiency and intercellular CO2 concentration) and quantitative/qualitative estimation of sugars in 90 days old plants. Studies revealed that increased Cd toxicity altered the level of elements. Metal stress adversely affected the photosynthetic system. However, results showed the essential role of carbohydrates in the cell metabolism and plant defence by their quantitative prevalence in response to Cd stress.