Pathways of root uptake and membrane transport of Cd2+in the zinc/cadmium hyperaccumulating plant Sedum plumbizincicola.
Uptake and membrane transport of cadmium (Cd) in roots of the hyperaccumulator Sedum plumbizincicola X.H. Guo et S.B. Zhou ex L.H. Wu was characterized by assessing the impact of various inhibitors and ion channel blockers on Cd accumulation as well as the real-time net Cd2+flux at the roots with application of the scanning ion-selective electrode technique. The uncouplers 2,4-dinitrophenol and P-type adenosine triphosphatase inhibitor Na3VO4significantly limited Cd2+uptake and transport kinetics in the root of S. plumbizincicola. These findings indicate that Cd is actively taken up into the roots. The Cd content in plant was significantly decreased with pretreatments of the Ca2+channel blocker La3+or Gd3+and the K+channel blocker tetraethylammonium, as well as in the presence of higher concentration of Ca2+and K+. These findings indicated that uptake of Cd2+into the root of S. plumbizincicola proceeds through ion channels that are permeable to both Ca2+and K+as confirmed by the direct evidence of real-time net Cd2+fluxes at the root surface in the treatments with ion channel inhibitors, as well as in the presence of elevated concentrations of Ca2+and K+. In addition, the results suggested a role for phytochelatin and protein synthesis in mediating Cd2+uptake by S. plumbizincicola. These findings increase the understanding of Cd2+uptake and membrane transport pathways in roots of the Zn/Cd hyperaccumulator S. plumbizincicola. Environ Toxicol Chem 2017;36:1038-1046. © 2016 SETAC.
Key Laboratory of Coastal Zone Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Shandong Provincial Key Laboratory of Coastal Zone Environmental Processes, Yantai, People's Republic of China.
Lian-Zhen
LZ
Li
Key Laboratory of Coastal Zone Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Shandong Provincial Key Laboratory of Coastal Zone Environmental Processes, Yantai, People's Republic of China.
Chen
C
Tu
Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, People's Republic of China.
Long-Hua
LH
Wu
Center for Safety of Products and Substances, National Institute of Public Health and the Environment, Bilthoven, The Netherlands.|Institute of Environmental Sciences (CML), Leiden University, Leiden, The Netherlands.
Willie J G M
WJ
Peijnenburg
Department of Plant Biology, Southern Illinois University Carbondale, Carbondale, Illinois, USA.
Stephen
S
Ebbs
Key Laboratory of Coastal Zone Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Shandong Provincial Key Laboratory of Coastal Zone Environmental Processes, Yantai, People's Republic of China.
Yong-Ming
YM
Luo
D001692:Biological Transport; D002104:Cadmium / Q000032:analysis / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D018517:Plant Roots / Q000737:chemistry / Q000378:metabolism*; D031963:Sedum / Q000737:chemistry / Q000378:metabolism*; D012989:Soil Pollutants / Q000032:analysis / Q000378:metabolism*; D015032:Zinc / Q000032:analysis / Q000378:metabolism*
D012989:Soil Pollutants; D002104:Cadmium; D015032:Zinc
Cadmium; Hyperaccumulator; Ion-selective electrode technique; Sedum plumbizincicola