Effect of lead stress on the growth and metabolism of Eruca sativa M. seedlings

Abstract

Among the toxic elements, lead has great importance because of its harmful effects on animal and human health. Heavy metals are known as growth inhibitors and consequently exhibit toxicity symptoms in plants. The effect of different concentrations of lead on seed germination, seedling growth and some metabolites ofEruca sativaplants was examined. The percentage of seed germination gradually decreased with an increase in the lead concentration. A considerable reduction in fresh and dry matter as well as shoot and root length was obtained as a result of increasing lead concentration. Among these parameters, total root length was a more sensitive parameter than shoot length at every lead concentration. The proline content increased, in most cases, with increasing lead concentration. The same trend was observed for the free amino acid content. Soluble protein generally increased with an increase in lead concentration. In contrast, the total protein gradually decreased as the lead concentration increased, particularly at the highest levels used.