INFLUENCE OF TI(IV)-ASCORBATE ON SOLUBLE CARBOHYDRATE CONTENT IN WHEAT SEEDLINGS EXPOSED TO CADMIUM

The water-soluble carbohydrates contributing to the response of wheat seedlings to cadmium stress in nutrient solution were studied with or without Ti(IV)-ascorbate supply. The total water-soluble carbohydrate, glucose, fructose, sucrose, glucan and fructan contents, and the cadmium and titanium contents were measured in wheat seedlings exposed to 10-4 M Cd or 10-5M Cd with either Ti(IV)-ascorbate or Na-ascorbate in the medium. Glucose, fructose and fructan showed the greatest response to Cd, ascorbate and titanium treatments. The sugar content in plants exposed to Cd increased with the metal concentration. Titanium tended to decrease the cadmium-induced sugar accumulation. Ti(IV)-ascorbate and Na-ascorbate were also applied without Cd to study the effect of these chemicals. In general, Na-ascorbate induced a higher accumulation of sugar components than Ti(IV)-ascorbate. Titanium addition in Cd-containing solution caused a significant decrease in the cadmium accumulation in the leaves. An increase in titanium content was observed only in the roots, higher values being measured in plants grown in solution containing 10-4 M Cd.