Effect of Bacillus cereus and selenium on some morpho-physiological characteristics and ion content of Salsola arbuscula under lead stress (Research Paper)

Abstract

In recent years, due to the development of mining operations, all kinds of heavy metals have entered the natural fields. Due to the long-term stability of heavy elements in the soil and in order to prevent them from entering the food chain, it is necessary to remove them from the soil with environmentally friendly methods such as phytoremediation. This research was conducted with the aim of evaluating the effect of plant growth promoting bacteria (Bacillus cereus) and selenium on the phytoremediation ability of Salsola arbuscula in lead-contaminated soil. For this purpose, a factorial experiment was conducted in the form of a completely randomized design in three replications, where the investigated factors included lead concentration with three levels (control, 100 and 200 mg/kg soil), plant growth promoting bacteria and selenium (control and 6 µmol) each was considered with two levels. The results showed that the increase in lead decreased the absorption of elements, the amount of chlorophyll, and the dry weight of the plant, and caused a significant increase in proline and anthocyanin and the accumulation of lead in the roots. The simultaneous use of selenium and Bacillus cereus increased root lead by 40%, plant dry weight by 29%, chlorophyll by 36%, and potassium, magnesium, and iron by 17, 18, and 27%. The simultaneous use of selenium and Bacillus cereus decreased anthocyanin by 30% and proline by 20%. Considering the accumulation of lead in the roots of Salsola arbuscula, it was concluded that this plant is suitable for the process of phytostabilization in lead-contaminated soils, and Bacillus cereus and selenium increased its phytoremediation ability by improving the biochemical conditions.