Planta

, Volume 214, Issue 4, pp 635–640 | Cite as

Phytochelatin synthesis is not responsible for Cd tolerance in the Zn/Cd hyperaccumulator Thlaspi caerulescens (J. & C. Presl)

  • Stephen Ebbs
  • Ingar Lau
  • Beth Ahner
  • Leon Kochian
Original Article

Abstract.

Thlaspi caerulescens (J. & C. Presl, "Prayon") is a heavy-metal hyperaccumulator that accumulates Zn and Cd to high concentrations (40,000 and 4,000 mg kg DW–1, respectively) without phytotoxicity. The mechanism of Cd tolerance has not been characterized but reportedly involves vacuolar sequestration. The role of phytochelatins (PCs) in metal tolerance in T. caerulescens and the related non-accumulator T. arvense was examined. Although PCs were produced by both species in response to Cd, these peptides do not appear to be involved in metal tolerance in the hyperaccumulator. Leaf and root PC levels for both species showed a similar positive correlation with tissue Cd, but total PC levels in the hyperaccumulator were generally lower, despite correspondingly higher metal concentrations. The lack of a role for PCs in the hyperaccumulator's response to metal stress suggests that other mechanisms are responsible Cd tolerance. The lower level of leaf PCs in T. caerulescens also implies that Cd in the shoot is sequestered in a compartment or form that does not elicit a PC response.

Cadmium Hyperaccumulator Metal tolerance Phytochelatin Thlaspi (Cd tolerance) 

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Copyright information

© Springer-Verlag 2001

Authors and Affiliations

  • Stephen Ebbs
    • 1
  • Ingar Lau
    • 2
  • Beth Ahner
    • 2
  • Leon Kochian
    • 3
  1. 1.Department of Plant Biology, Southern Illinois University Carbondale, Carbondale, IL 62901, USA
  2. 2.Department of Agricultural and Biological Engineering, Cornell University, Ithaca, NY 14853, USA
  3. 3.U.S. Plant, Soil, and Nutrition Laboratory, USDA-ARS, Cornell University, Ithaca, NY 14853, USA

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