Plant Physiology Preview Published on January 15, 2004; 10.1104/pp.103.031948
Received August 21, 2003
Returned for revision September 10, 2003
Accepted October 20, 2003
Hyperaccumulation of Cadmium and Zinc in Thlaspi caerulescens and Arabidopsis halleri at the LeafCellular Level
Claudia Cosio *, Enrico Martinoia , and Catherine Keller
Institut des Sciences et techniques de l’environnement-Laboratoire de pedologie, Faculté d’environnement naturel architectural et carstruit, Ecole Polytechnique Féderale de Lausanne, Lausanne, Switzerland (C.C., C.K.); and Institut für Pflanzenbiologie, Universität Zurich, Zurich, Switzerland (E.M.)
* Corresponding author; email: claudia.cosio{at}epfl.ch.
Vacuolar compartmentalization or cell wall binding in leaves could play a major role in hyperaccumulation of heavy metals. However, little is known about the physiology of intracellular cadmium (Cd) sequestration in plants. We investigated the role of the leaf cells in allocating metal in hyperaccumulating plants by measuring short-term 109Cd and 65Zn uptake in mesophyll protoplasts of Thlaspi caerulescens "Ganges" and Arabidopsis halleri, both hyperaccumulators of zinc (Zn) and Cd, and T. caerulescens "Prayon," accumulating Cd at a lower degree. The effects of low temperature, several divalent cations, and pre-exposure of the plants to metals were investigated. There was no significant difference between the Michaelis-Menten kinetic constants of the three plants. It indicates that differences in metal uptake cannot be explained by different constitutive transport capacities at the leaf protoplast level and that plasma and vacuole membranes of mesophyll cells are not responsible for the differences observed in heavy metal allocation. This suggests the existence of regulation mechanisms before the plasma membrane of leaf mesophyll protoplasts. However, pre-exposure of the plants to Cd induced an increase in Cd accumulation in protoplasts of "Ganges," whereas it decreased Cd accumulation in A. halleri protoplasts, indicating that Cd-permeable transport proteins are differentially regulated. The experiment with competitors has shown that probably more than one single transport system is carrying Cd in parallel into the cell and that in T. caerulescens "Prayon," Cd could be transported by a Zn and Ca pathway, whereas in "Ganges," Cd could be transported mainly by other pathways.
This article has been cited by other articles:

|
 |

|
 |
 
L.-l. Lu, S.-k. Tian, X.-e Yang, X.-c. Wang, P. Brown, T.-q. Li, and Z.-l. He
Enhanced root-to-shoot translocation of cadmium in the hyperaccumulating ecotype of Sedum alfredii
J. Exp. Bot.,
August 1, 2008;
59(11):
3203 - 3213.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
M. A. Klein, H. Sekimoto, M. J. Milner, and L. V. Kochian
Investigation of Heavy Metal Hyperaccumulation at the Cellular Level: Development and Characterization of Thlaspi caerulescens Suspension Cell Lines
Plant Physiology,
August 1, 2008;
147(4):
2006 - 2016.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
M. Jasinski, D. Sudre, G. Schansker, M. Schellenberg, S. Constant, E. Martinoia, and L. Bovet
AtOSA1, a Member of the Abc1-Like Family, as a New Factor in Cadmium and Oxidative Stress Response
Plant Physiology,
June 1, 2008;
147(2):
719 - 731.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
S. Uraguchi, I. Watanabe, A. Yoshitomi, M. Kiyono, and K. Kuno
Characteristics of cadmium accumulation and tolerance in novel Cd-accumulating crops, Avena strigosa and Crotalaria juncea
J. Exp. Bot.,
September 1, 2006;
57(12):
2955 - 2965.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
A. Hirner, F. Ladwig, H. Stransky, S. Okumoto, M. Keinath, A. Harms, W. B. Frommer, and W. Koch
Arabidopsis LHT1 Is a High-Affinity Transporter for Cellular Amino Acid Uptake in Both Root Epidermis and Leaf Mesophyll
PLANT CELL,
August 1, 2006;
18(8):
1931 - 1946.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
C. Cosio, L. DeSantis, B. Frey, S. Diallo, and C. Keller
Distribution of cadmium in leaves of Thlaspi caerulescens
J. Exp. Bot.,
February 1, 2005;
56(412):
765 - 775.
[Abstract]
[Full Text]
[PDF]
|
 |
|
|
|