Influence of combined stress by salinity (NaCl) and heavy metals (Pb(NO3)2) on the proline, chlorophyll and lead accumulation in the tissues of the Atriplex canescens (Pursh ) Nutt.

Abstract. Salinity and heavy metals pollution are the root causes of many environmental problems. This study aims to determine the effect of NaCl-induced salinity and Pb(NO3)2 on chlorophyll, proline content, and lead accumulation in shoots and roots of Atriplex canesens. Sowing was carried out in plastic pots (16 cm in diameter and 13.8 cm high) containing a mixture of sand/compost. The irrigation of plants was performed with distilled water and Hoagland nutrient solution. After four months of growth, the plants were subjected to either 0.50 or 3% of NaCl combined with 800, 1600, and 2400 ppm of Pb(NO3)2 for a duration of one month, then we performed biochemical and chemical analyses on the plants. Results showed that the combined influence of strong salinity and lead caused a reduction of chlorophyll and increased proline and lead accumulation in plant tissues. Lead significantly accumulated in the roots compared to the shoots of the plants.