Interactive effect of cadmium and gibberellic acid on metabolic constituents of cowpea (Vigna unguiculata L.)‎ plant

الملخص EN

The effects of different concentrations (0, 20, 40, 80, 160 ppm) of cadmium chloride (CdCl2) in the presence or absence of 100 ppm gibberellic acid (GA3) on photosynthetic pigments (chlorophyll a, chlorophyll b and carotenoids) levels in leaves, and on carbohydrate (reducing, non-reducing, total) and protein contents in roots and shoots of cowpea (Vigna unguiculata L.) at three growth stages (early, intermediate, late) were investigated.

In the presence of CdCl2, a variable degree of reduction in the level of photosynthetic pigments was observed in the leaves of cowpea.

Cadmium chloride treatment decreased the carbohydrate and soluble protein contents of cowpea shoots and roots.

This reduction was more significant at higher Cd concentrations and during the early growth stage, and became less significant at the later phenological phases of growth.

Application of GA3 simultaneously with different concentrations of CdCl2 tended to alleviate, to different degrees, the Cd-induced reduction in pigments, carbohydrate and protein levels particularly at lower Cd concentrations and during the intermediate stage followed by the early growth stage, thus pointing to the role of GA3 in reducing the inhibitory effect of Cd .

Roots were more affected by Cd treatments and less affected by the combined treatments of Cd and GA3 than shoots.