DYNAMICS OF THREE ORGANIC ACIDS (MALIC,ACETIC AND SUCCINIC ACID) IN SUNFLOWER EXPOSED TO CADMIUM AND LEAD |
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| Authors: | Niu Zhixin Li Xiaodong Sun Lina Sun Tieheng |
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| Institution: | 1. Key Laboratory of Regional Environment and Eco-remediation , Shenyang , China;2. Environmental Simulation and Pollution Control State Key Joint Laboratory , Beijing Normal University , Beijing , China;3. Liaoning Province Academic of Environmental Science , Shenyang , China;4. Key Laboratory of Regional Environment and Eco-remediation , Shenyang , China;5. Institute of Applied Ecology, Chinese Academy of Sciences , Shenyang , China |
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| Abstract: | Sunflower (Helianthus annuus L.) has been considered as a good candidate for bioaccumulation of heavy metals. In the present study, sunflower was used to enrich the cadmium and lead in sand culture during 90 days. Biomass, Cd and Pb uptake, three organic acids and pH in cultures were investigated. Results showed that the existence of Cd and Pb showed different interactions on the organic acids exudation. In single Cd treatments, malic and acetic acids in Cd10 showed an incremental tendency with time. In the mixed treatments of Cd and Pb, malic acids increased when 10 and 40 mg?L–1 Cd were added into Pb50, but acetic acids in Pb50 were inhibited by Cd addition. The Cd10 supplied in Pb100 stimulated the secretion of malic and succinic acids. Moreover, the Cd or Pb uptake in sunflower showed various correlations with pH and some organic acids, which might be due to the fact that the Cd and Pb interfere with the organic acids secretion in rhizosphere of sunflower, and the changes of organic acids altered the form and bioavailability of Cd and Pb in cultures conversely. |
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| Keywords: | organic acids heavy metals pH bioaccumultion |
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