Résumé:
Lead is the most important toxic element in the environment that affects the life of living
organisms. In plants, lead plays no physiological role, its presence is a source of multiple
disturbances even at low concentrations. The objective of this work is to evaluate the stressful
effect of lead on the biochemical parameters of Cleome amblyocarpa Barr. & Murb., In order to
assess its ability to decontaminate polluted soil. In order to achieve these objectives, the
experiment is carried out on plants of Cleome, He chose because of its adaptation to the climatic
and edaphic conditions of the Saharan ecosystem, as well as for its rapid growth and its
significant biomass. He was exposed to different doses of lead (0, 250, 500, 1000, 1500, 2000,
2500 and 3000 ppm) in the form of lead nitrate (Pb(NO3)2) added to the growing medium which
consists of sand and potting soil (95% soil / 5% potting soil). The estimate of plant responses to
applied stress is measured by all the biochemical parameters. Accumulation of lead in stressed
plants is accompanied by a drop in the yield of protein content, application of stress to lead
resulted in increased accumulation of chlorophyll and soluble sugars.
