Résumé:
Lead is one of the most toxic heavy metals, it causes considerable damage in plants. This work is to
follow the behavior of the bean (Vicia faba L.) cope with stress of lead. This plant is used as a model in
ecotoxicological studies due to its large amount of biomass and its short growing season.
The objective of our work is to study the influence of lead as nitrates Pb(NO3)2 at doses of 0, 500 and
1000 ppm, on the behavior morpho-physiological, anatomical and on mechanisms intervenants volved in the
process of seed germination of plants from both varieties Sidi Aich and Super Aguadulce. The plant has
been stressed at doses of lead of 0, 500 and 1000 ppm. This stress was applied twice during the growing
cycle of the plant.
The results indicate that seed germination is strongly inhibited and the mechanisms intrvenants in this
process are changeable due to this stress. The presence of lead decreases the photosynthetic activity and
production of biomass parameters accompanied by a reduction of the protein content in the grains of the
culture. These results also show an accumulation of soluble sugars and proline, expressing a mechanism for
regulating of the potentiel internal face of the action of metal stress. The effect of lead stress and of the plant
genotype is significant on the anatomic parameter of the plant.
These results suggest that the presence of lead alters the normal functioning and development of
plants by disturbances on the morphological, physiological, biochemical and anatomical behavior of the
plant.
