Sub‐cellular localization of Ni in the hyperaccumulator, Hybanthus floribundus (Lindley) F. Muell

• Published in: Plant, cell and environment Vol. 27; no. 6; pp. 705 - 716
• Main Authors: BIDWELL, S. D., CRAWFORD, S. A., WOODROW, I. E., SOMMER‐KNUDSEN, J., MARSHALL, A. T.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science Ltd 01-06-2004; Blackwell; Wiley Subscription Services, Inc
• Subjects: Animal, plant and microbial ecology; Applied ecology; Biological and medical sciences; Ecotoxicology, biological effects of pollution; Effects of pollution and side effects of pesticides on plants and fungi; Fundamental and applied biological sciences. Psychology; Hybanthus floribundus; hyperaccumulator; localization; nickel; X‐ray microanalysis; localization; nickel; X-ray microanalysis; Hybanthus floribundus; hyperaccumulator; Tolerance; Plant leaf; Vacuole; Cell wall
• ISSN: 0140-7791; 1365-3040
• DOI: 10.1111/j.0016-8025.2003.01170.x

ABSTRACT
The cellular and subcellular distribution of Ni within leaves of Hybanthus floribundus (Lindley) F. Muell, a hyperaccumulator of Ni, was investigated at relatively high spatial resolution using energy‐dispersive X‐ray microanalysis (EDAX). Elemental distribution maps showed that Ni was predominantly localized in the vacuoles of epidermal cells in the leaves. Quantification of Ni revealed concentrations up to 275 mmol kg−1 (embedded tissue) in some epidermal vacuoles. The accumulation of Ni in these cells was associated with a decrease in the concentration of Na and K. There was no indication that Ni was associated with P, S or Cl in the vacuoles. Ni was also concentrated on the outside of cell walls throughout the leaves, indicating that apoplastic compartmentation is also involved in Ni tolerance and accumulation in this plant.