Effect of zinc on parameters (protein, soluble sugar and proline) in bean (vicia faba l.)

The use of solid urban waste as fertilizer causes soil and plant contamination by heavy metals. Heavy metals, such as Cu, Zn, Pb, Cd, Cr... pose particularly serious problems for agriculture with adverse effects on crop production and biodiversity. In our study, we are interested in discovering the biochemical behavior of a model plant Vicia faba L. in the face of metallic stress. For this, we studied the effect of four concentrations of zinc sulphate (0, 300, 500 and 700 ppm) for 2 weeks after 45 days of growth of the plant. Levels of protein, proline and soluble sugars were analyzed spectrophotometry. The results show a significant reduction in protein levels according to the progressive increase of the metal (Zinc), with the observation that the contents in the leaves are higher than those of the roots, noting that the lowest values are obtained at the dose of 700 ppm zinc (56.503 mg g-1 dry weight). On the other hand, the same dose of Zinc leads to a significant increasing accumulation of the proline and soluble sugar content relative to the control according to the increasing concentration of metal (zinc) at leaf levels much more than roots. The content of proline and the higher soluble sugars (182.977 mg g-1 dry weight and 70.859 mg g-1 dry weight respectively) are obtained at a dose of 700 ppm zinc.