Author:
Souri Mohammad Kazem,Hatamian Mansoure,Tesfamariam Tsehaye
Abstract
Abstract
Background
Contamination of vegetable crops with heavy metals is a great threat to human health. On the other hand, monitoring plant tissue content of heavy metals at different growth stages could have important implications. In this study, shoot and root samples of garden cress and sweet basil were collected from five farms, from heavy metal polluted fields located in Shahre Rey, south of Tehran, Iran, in either young (3 weeks old) or mature (7 weeks old) plants. The concentrations of cadmium (Cd), lead (Pb), nickel (Ni), arsenic (As), chromium (Cr), cobalt (Co), copper (Cu), manganese (Mn) and zinc (Zn) in plant tissues were determined using atomic absorption spectroscopy. In another study, 2 weeks (young) or 6 weeks old (mature) plants of garden cress were subjected to three concentrations of Cd and Pb (0, 5, 10 mg L−1) under hydroponic sand culture for 5 days, in which Hoagland formula was used for nutrient solution preparation.
Results
The results showed that root concentration of various heavy metals, particularly Cd, As, Ni, Co, Cu, Mn and Zn but not Pb were significantly higher than their shoot concentration in either crop under field sampling. The leaf concentration of some heavy metals was significantly different in seedling and older (mature) plant samples of either crop. Young plant leaves of sweet basil had significantly less Cd, Pb, As and higher Cu than mature plants, whereas young garden cress plants had similar Cd, Pb and higher As and Zn concentrations than mature plants. The Cr, Co, Mn and Zn concentrations were similar in young and mature plants of sweet basil. The Mn, Co, Cr and Ni concentration of young and mature plants of either crop was also similar. The result of hydroponic study showed that young plants of garden cress had higher potential to accumulate lead in shoot and root, particularly in lower (5 mg L−1) than higher (10 mg L−1) lead concentration; however, root Pb concentration at 10 mg L−1 Pb of nutrient solution showed no difference between young and mature plants. Regarding cadmium, young garden cress plants accumulated higher Cd than mature plants in their shoot, particularly under higher Cd levels (10 rather than 5 mg L−1) of nutrient solution; however, a wide difference in root Cd concentration was observed under low (5 mg L−1) than higher (10 mg L−1) cadmium concentration of nutrient solution.
Conclusion
The results of these two studies indicate that despite that young plants have a higher potential for heavy metal uptake and accumulation, the low difference in young and mature plants in the polluted fields may be due to the longer period of plant growth of mature plants that may increase the risk of exposure to polluted air and dust deposition containing high levels of heavy metals.
Publisher
Springer Science and Business Media LLC
Subject
Agronomy and Crop Science,Biochemistry,Food Science,Biotechnology
Reference30 articles.
1. Alexander PD, Alloway BJ, Dourado AM. Genotypic variations in the accumulation of Cd, Cu, Pb and Zn exhibited by six commonly grown vegetables. Environ Pollut. 2006;144:736–45.
2. Arambašić MB, Bjelić S, Subakov G. Acute toxicity of heavy metals (copper, lead, zinc), phenol and sodium on Allium cepa L., Lepidium sativum L. and Daphnia magna St.: comparative investigations and the practical applications. Water Res. 1995;29(2):497–503.
3. Bosiacki M, Zieleziński Ł. Phytoextraction of nickel by selected species of lawn grasses from substrates contaminated with heavy metals. Acta Scientarum Polonorum Hortorum Cultus. 2011;10(3):155–73.
4. Cheng MM, Wang P, Kopittke PM, Wang A, Sale PWG, Tang CX. Cadmium accumulation is enhanced by ammonium compared to nitrate in two hyperaccumulators, without affecting speciation. J Exp Bot. 2016;67:5041e5050.
5. Delbari AS, Kulkarni DK. Accumulation of heavy metals in vegetables grown along national high ways-a case study of Tehran-Iran. Int J Eng Sci Invent. 2014;3:77–82.