DISTRIBUTION OF CADMIUM IN SHOOT AND ROOT TISSUES OF MAIZE AND PEA-PLANTS - PHYSIOLOGICAL DISTURBANCES

Maize and pea plants were treated with 0.0 (control), 0.01 or 0.05 mM Cd in the growing medium for 11 d. Although the total Cd concentration was similar in shoot and root tissues of both species, pea plants sho wed more severe toxic symptoms. The fresh weight and percentage of wat er content of root and shoot decreased concomitantly to Cd supply. Hig h Cd levels were found in the cell-wall fraction (Fraction I) and in F raction IV (soluble) of maize plants, whereas Cd-treated pea accumulat ed more Cd in the soluble fraction. The protein concentration of Fract ion IV of pea shoot and root significantly increased upon treatment wi th 0.05 mM Cd, whereas maize showed no effect. Furthermore, a previous ly not visible protein (similar to 12 kDa), appeared in Fraction IV of pea root grown with the highest Cd supply. Cadmium treatment, in gene ral, notably enhanced the concentrations of 2-thiobarbituric acid reac tive material (lipid peroxidation products) in pea fractions, presumab ly due to Cd-induced oxidative stress.