Journal of Soil and Plant Interactions

In recent years, the use of biological stimulants has been considered to increase the efficiency of phytoremediation of heavy elements. The present study was conducted with the aim of evaluating the effect of the combined use of citric acid and plant growth promoting rhizobacteria (Bacillus cereus) on the plant-remediation ability of Salsola imbericata in cadmium-contaminated soils. To carry out this research, a factorial experiment in a completely randomized design in three replications including cadmium with three levels (control, 30 and 60 mg/liter), seed inoculation with Bacillus cereus and citric acid with two levels was considered. The results showed that with the increase of cadmium concentration, dry biomass of the plant, the amount of chlorophyll and the amount of iron absorption in the plant decreased by 56, 53 and 35% respectively, while the amount of cadmium, proline and anthocyanin increased by 75, 71 and 41% respectively. The use of citric acid and inoculation with plant growth promoting rhizobacteria improved the growth conditions of the plant, so that the combined use of these two at a concentration of 30 ppm cadmium increased biomass, chlorophyll and iron in the plant by 43, 56 and 29%, respectively. The combined use of bacteria and citric acid also caused a 58% increase in root cadmium absorption. The amount of cadmium in the aerial parts of the plant was undetectable. Therefore, it was concluded that Salsola imbericata is a suitable plant for cadmium phytoextraction and the use of citric acid and Bacillus cereus bacteria can increase its ability for phytoextraction of cadmium.