Effect of solution pH on Cd absorption of rice seedlings

The Cd uptake of rice seedlings was investigated as affected by the pH using a hydroponic experiment.The Cadmium concentration of nutrient solution was 10 mg/L and the pH varied from 4.0 to 7.5.The results showed that the content and accumulation of Cd in the shoot tissues of two rice varieties reached the maximum at pH 5.0.In contrast,that in the root increased with the increase of solution pHand was the highest at pH 7.5.Both of two trends may be described well with quadratic equations.Moreover,Cadmium stress reduced the fresh and dry weight of rice tissues but increased the content of MDA and proteins significantly.Therefore,under the condition of certain concentration of Cd,the absorption of Cd in the shoot and root of rice could be differently affected by different solution pH,and 10 mg/L Cd inhibited the growth of rice seedlings.