Department of Biology, Faculty of Science, University of Birjand, Birjand, Iran.
Abstract: (532 Views)
Abstract
In some saline areas, pollutants such as heavy metals have been spread due to industrial activities. Halophyte plants can be useful for phytoremediation of such areas. To investigate the effect of salinity and heavy metal copper and their interaction effect on the halophyte plant Bassia scoparia L., two factorial experiments were conducted in a completely randomized design in hydroponics laboratory of Birjand University. In the first experiment, interaction effects of five levels of salinity (0, 100, 200, 300, and 400 mM) and five levels of copper (0, 50, 100, 200, and 300 mg/L) on the germination characteristics of B. scoparia seeds were measured. Results of this experiment showed that the increase in salinity and copper concentration had a significant negative effect on the germination and growth of seedlings. In the second experiment, the effects of three levels of salinity (0, 100, and 300 mM) and three levels of copper (0, 50, and 100 mg/L) on the traits related to growth and sodium and copper contents in root and shoot were investigated in pot culture. Salinity significantly increased the amount of sodium in root and shoot but did not affect the amount of copper in root and shoot. In the copper treated conditions, amount of this metal increased in root and shoot of B. scoparia. However, by having accumulation factors of less than one, B. scoparia does not seem suitable for plant extraction of copper, although it can be used to stabilize this metal by having a suitable biomass and considerable absorption of copper in root.
Background and Objective: One of the serious environmental pollutants is heavy metals, which have been rapidly increasing over the years due to industrial processes and human activities. Copper (Cu) is one of the heavy metals that causes toxicity in many plant species. Screening different plants is very important to know their capability for phytoremediation of heavy metals, especially under stressful environmental conditions such as salt stress. This research examines the phytoremediation capability of Bassia scoparia L. for copper under salt stress.
Methods: To investigate the effect of different levels of salinity and Cu and their interaction on B. scoparia, two factorial experiments were conducted in a completely randomized design with three replications. In the first experiment, the interaction effects of five levels of salinity (0, 100, 200, 300, and 400 mM NaCl) and five levels of Cu (0, 50, 100, 200, and 300 mg/L) on the germination characteristics of B. scoparia seeds were measured. In the second experiment, the effects of three levels of salinity (0, 100, and 300 mM) and three levels of Cu (0, 50, and 100 mg/L) on the lengths and dry weights of root and shoot, the amounts of chlorophyll a, b, and carotenoid, the amounts of Na and Cu in the root and shoot were investigated. After measuring the concentrations of Na and Cu in the roots and shoots, the accumulation coefficients of these elements, including bioconcentration factor (BCF), accumulation factor (AF), and translocation factor (AF) were also calculated.
Results: The results of the first experiment showed that the increase in salinity and Cu had a significant effect on the percentage, index, and speed of germination, lengths of shoot and root, and dry weights of shoot and root of seedlings so that both treatments and their combination reduced these germination traits. Germination almost stopped under the simultaneous treatment of Cu and salinity at high concentrations. According to the results of the second experiment, salt and Cu at high concentrations caused a decrease in the growth and development of the plant, and this decrease was greater under their combined stressful conditions. Salinity significantly increased the amounts of sodium in the root and shoot but did not affect the amounts of Cu in the root and shoot. In the copper treated conditions, the amount of this metal was increased in the root and shoot of plants.
Conclusions: Although B. scoparia shows high resistance to salinity and tolerates moderate concentrations of Cu, it is unable to tolerate the simultaneous treatment of Cu and salinity. It is also sensitive to high concentrations of Cu. Moreover, considering that the accumulation coefficients (AF, BCF, and TF) for Cu in B. scoparia were less than one, this plant does not seem to be suitable for plant extraction of Cu, although it can be used to stabilize this metal by having suitable biomass and significant absorption of Cu in the root.
References:
1. Al Defferi, M. E., AL-Janabi, Q. A., Mustafa, S. A., AL-Muttarri, A. K., 2019. Phytoremediation of lead and nickel by Bassia scoparia. Plant Arch. 19(2), 3830–3834. http://dx.doi.org/10.13140/RG.2.2.22142.13128.
2. Mousavi Kouhi, S. M., Moudi, M., 2020. Assessment of phytoremediation potential of native plant species naturally growing in a heavy metal-polluted saline–sodic soil. Environ. Sci. Pollut. Res. 27(9), 10027–10038. https://link.springer.com/article/10.1007/s11356-019-07578-6.
3. Usman, A. R. A., Kuzyakov, Y., Stahr, K., 2018. Effect of immobilizing substances and salinity on heavy metals availability to wheat grown on sewage sludge-contaminated soil. Soil Sediment Contam. 14(4), 329–344. https://doi.org/10.1080/15320380590954051.
Type of Study:
Research |
Subject:
Plant growth under stressful conditions Received: 2024/07/9 | Accepted: 2024/09/8 | Published: 2024/11/25