Heavy metals stress is one of the major abiotic stresses that cause environmental pollution and hence indefinite hazards to living organisms in recent decades. The current study was conducted with the goal in the mind to clarify the ameliorative role of seed presoaking in kinetin (30 ppm ) and/or calcium chloride (40 mM) in counteracting the deteriorative effect of foliar application of nickel (2.5 mM) and/or lead (0.5mM) on the growth and some metabolic activities of Phaseolus vulgaris L. plant. Nickel and/or lead treatments significantly reduced the leaves area/plant, total pigments, soluble and insoluble sugars, amino-nitrogen, catalase enzyme, total nitrogen, potassium, calcium and magnesium contents. On the other hand, proline, amino-N, MDA, total phenols, SOD, POX, nickel and lead contents were significantly increased in response to heavy metal treatments. On contrary, seed presoaking in kinetin and calcium chloride alone or in combination significantly increased the leaves area/plant, total pigments, soluble and insoluble sugars, amino-nitrogen, catalase enzyme, total nitrogen, potassium, calcium and magnesium contents. Meanwhile, proline, MDA, total phenols, SOD, POX, nickel and lead contents were significantly decreased by kinetin and calcium chloride treatments. Kinetin and/or calcium chloride were found to be the most effective in enhancing the plant tolerance towards nickel and/or lead toxicity. |
