This Article Full Text Full Text (PDF) All Versions of this Article: 134/3/1113    most recent pp.103.033506v1 Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via ISI Web of Science (51) Citing Articles via Google Scholar Google Scholar Articles by Raab, A. Articles by Meharg, A. A. Search for Related Content PubMed PubMed Citation Articles by Raab, A. Articles by Meharg, A. A. Agricola Articles by Raab, A. Articles by Meharg, A. A.

ENVIRONMENTAL STRESS AND ADAPTATION

The Nature of Arsenic-Phytochelatin Complexes in Holcus lanatus and Pteris cretica¹

Department of Chemistry, University of Aberdeen, Meston Building, Meston Walk, Aberdeen AB24 3UE, United Kingdom (A.R., J.F.); and School of Biological Sciences, University of Aberdeen, Cruickshank Building, St. Machar Drive, Aberdeen, AB24 3UU, United Kingdom (A.A.M.).

We have developed a method to extract and separate phytochelatins (PCs)—metal(loid) complexes using parallel metal(loid)-specific (inductively coupled plasma-mass spectrometry) and organic-specific (electrospray ionization-mass spectrometry) detection systems—and use it here to ascertain the nature of arsenic (As)-PC complexes in plant extracts. This study is the first unequivocal report, to our knowledge, of PC complex coordination chemistry in plant extracts for any metal or metalloid ion. The As-tolerant grass Holcus lanatus and the As hyperaccumulator Pteris cretica were used as model plants. In an in vitro experiment using a mixture of reduced glutathione (GS), PC₂, and PC₃, As preferred the formation of the arsenite [As^(III)]-PC₃ complex over GS-As^(III)-PC₂, As^(III)-(GS)₃, As^(III)-PC₂, or As^(III)-(PC₂)₂ (GS: glutathione bound to arsenic via sulphur of cysteine). In H. lanatus, the As^(III)-PC₃ complex was the dominant complex, although reduced glutathione, PC₂, and PC₃ were found in the extract. P. cretica only synthesizes PC₂ and forms dominantly the GS-As^(III)-PC₂ complex. This is the first evidence, to our knowledge, for the existence of mixed glutathione-PC-metal(loid) complexes in plant tissues or in vitro. In both plant species, As is dominantly in non-bound inorganic forms, with 13% being present in PC complexes for H. lanatus and 1% in P. cretica.

¹ This work was supported by the Biotechnology and Biological Science Research Council (grant no. I/REI 18479) and by the College of Engineering and Physical Sciences, Aberdeen, Aberdeenshire, UK.

^* Corresponding author; e-mail a.meharg{at}abdn.ac.uk; fax 44–0–1224–272703.

Received September 17, 2003; returned for revision October 19, 2003; accepted December 4, 2003.

This article has been cited by other articles:

				G. J. Norton, M. Nigar, P. N. Williams, T. Dasgupta, A. A. Meharg, and A. H. Price Rice-arsenate interactions in hydroponics: a three-gene model for tolerance J. Exp. Bot., May 2, 2008; (2008) ern098v1. [Abstract] [Full Text] [PDF]

				A. Raab, K. Ferreira, A. A. Meharg, and J. Feldmann Can arsenic-phytochelatin complex formation be used as an indicator for toxicity in Helianthus annuus? J. Exp. Bot., April 1, 2007; 58(6): 1333 - 1338. [Abstract] [Full Text] [PDF]

				P. Catarecha, M. D. Segura, J. M. Franco-Zorrilla, B. Garcia-Ponce, M. Lanza, R. Solano, J. Paz-Ares, and A. Leyva A Mutant of the Arabidopsis Phosphate Transporter PHT1;1 Displays Enhanced Arsenic Accumulation PLANT CELL, March 1, 2007; 19(3): 1123 - 1133. [Abstract] [Full Text] [PDF]

				S. Iglesia-Turino, A. Febrero, O. Jauregui, C. Caldelas, J. L. Araus, and J. Bort Detection and Quantification of Unbound Phytochelatin 2 in Plant Extracts of Brassica napus Grown with Different Levels of Mercury Plant Physiology, October 1, 2006; 142(2): 742 - 749. [Abstract] [Full Text] [PDF]

				D. R. Ellis, L. Gumaelius, E. Indriolo, I. J. Pickering, J. A. Banks, and D. E. Salt A Novel Arsenate Reductase from the Arsenic Hyperaccumulating Fern Pteris vittata Plant Physiology, August 1, 2006; 141(4): 1544 - 1554. [Abstract] [Full Text] [PDF]

				A. Al Agely, D. M. Sylvia, and L. Q. Ma Mycorrhizae Increase Arsenic Uptake by the Hyperaccumulator Chinese Brake Fern (Pteris vittata L.) J. Environ. Qual., November 7, 2005; 34(6): 2181 - 2186. [Abstract] [Full Text] [PDF]

				G.-L. Duan, Y.-G. Zhu, Y.-P. Tong, C. Cai, and R. Kneer Characterization of Arsenate Reductase in the Extract of Roots and Fronds of Chinese Brake Fern, an Arsenic Hyperaccumulator Plant Physiology, May 1, 2005; 138(1): 461 - 469. [Abstract] [Full Text] [PDF]

				L. Gumaelius, B. Lahner, D. E. Salt, and J. A. Banks Arsenic Hyperaccumulation in Gametophytes of Pteris vittata. A New Model System for Analysis of Arsenic Hyperaccumulation Plant Physiology, October 1, 2004; 136(2): 3198 - 3208. [Abstract] [Full Text] [PDF]