Co-contamination of soils with heavy metals or petroleum hydrocarbons is one of the important environmental problems. This study was done to evaluate the effect of ZnSO4 and salicylic acid (SA) on biological degradation of phenanthrene in the Cd polluted soil under sorghum cultivation inoculated with Pseudomonas putida (P.putida). Treatments were consisted of applying ZnSO4 (‌0 and 40 kg/ha), SA foliar application (0 and 1.5 mmol/lit), Cd polluted soil (0, 5 and 10 mg Cd/kg soil) and soil pollution with phenanthrene at the rates of 0, 3 and 6% (W/W) in three replicate in the presence of P. putida. Plant in this experiment was sorghum. At the end of this experiment, plant was harvested and the plant Cd concentration was measured using atomic absorption spectroscopy. On the other hand, the degradation of phenanthrene (%) in the soil and soil microbial respiration via evaluated CO2 were measured. Based on the results of this study, applying 40 kg/ha ZnSO4 significantly decreased the plant Cd concentration by 14.3 %. In addition, a significant increasing by 15.4 % in degradation of phenanthrene in soil was also observed when the soil received 40 kg/ha. The similar results were also observed for SA foliar application.Soil application of ZnSO4, the presence of P. putida and foliar application of salicylic acid can increase plant resistance to abiotic stresses and thereby have significant effect on biological degradation of phenanthrene. However, the role of plant type on degradation of phenanthrene cannot be ignored. Manuscript profile

Today, urban management seems necessary to remediate soils contaminated with heavy metals, especially in industrial regions. Thus, this research was done to evaluate the effect of zeolite and seed pre-treatment with salicylic acid on reducing the Cd sorption by ornamental sunflower under drought stress. Treatments (48 treatments) consisted of applying zeolite (0 and 5 % (W/W)) in the Cd (0 and 15 mg Cd (kg soil)-1) polluted soil under cultivation of ornamental sunflower that was inoculated with P.indica in normal and intensive drought stress condition. The plants seeds were pretreated with salicylic acid (0, 0.5 and 1 mM). After 90 days, plants were harvested and atomic absorption spectroscopy (Perkin-Elmer 3030) was used for determining the Pb and Zn concentration. Application of zeolite in the soil significantly decreased and increased the plant Cd and Zn concentration by 11.3 and 14.2%, respectively. Seed priming with salicylic acid at the rate of 1 mM significantly increased the plant Zn and Cd concentration by 12.7 and 14.2%, respectively. In addition, plant inoculation with P.indica significantly decreased the catalase (CAT) and ascorbate peroxidase (APX) enzyme activity which indicate the plant resistance to abiotic stress. However, drought stress had adverse effect on the Cd sorption by plants. Moreover, the CAT and APX enzymes activities were increased. The results of this study showed that applying zeolite and seed priming with salicylic acid had additive effects on decreasing the Cd sorption by ornamental sunflower that was inoculated with P.indica fungus under drought stress. Manuscript profile