Skip to main content
Plant Physiology logoLink to Plant Physiology
. 1992 Jun;99(2):428–433. doi: 10.1104/pp.99.2.428

Effect of Cadmium on γ-Glutamylcysteine Synthesis in Maize Seedlings 1

Adrian Rüegsegger 1, Christian Brunold 1
PMCID: PMC1080479  PMID: 16668902

Abstract

Cysteine, γ-glutamylcysteine, and glutathione and the extractable activity of the enzymes of glutathione biosynthesis, γ-glutamylcysteine synthetase (EC 6.3.2.2) and glutathione synthetase (EC 6.3.2.3), were measured in roots and leaves of maize seedlings (Zea mays L. cv LG 9) exposed to CdCl2 concentrations up to 200 micromolar. At 50 micromolar Cd2+, γ-glutamylcysteine contents increased continuously during 4 days up to 21-fold and eightfold of the control in roots and leaves, respectively. Even at 0.5 micromolar Cd2+, the concentration of γ-glutamylcysteine in the roots was significantly higher than in the control. At 5 micromolar and higher Cd2+ concentrations, a significant increase in γ-glutamylcysteine synthetase activity was measured in the roots, whereas in the leaves this enzyme activity was enhanced only at 200 micromolar Cd2+. Labeling of isolated roots with [35S]sulfate showed that both sulfate assimilation and glutathione synthesis were increased by Cd. The accumulation of γ-glutamylcysteine in the roots did not affect the root exudation rate of this compound. Our results indicate that maize roots are at least in part autonomous in providing the additional thiols required for phytochelatin synthesis induced by Cd.

Full text

PDF
428

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Alosi M. C., Melroy D. L., Park R. B. The regulation of gelation of Phloem exudate from cucurbita fruit by dilution, glutathione, and glutathione reductase. Plant Physiol. 1988 Apr;86(4):1089–1094. doi: 10.1104/pp.86.4.1089. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Bradford M. M. A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Anal Biochem. 1976 May 7;72:248–254. doi: 10.1006/abio.1976.9999. [DOI] [PubMed] [Google Scholar]
  3. Delhaize E., Jackson P. J., Lujan L. D., Robinson N. J. Poly(gamma-glutamylcysteinyl)glycine Synthesis in Datura innoxia and Binding with Cadmium : Role in Cadmium Tolerance. Plant Physiol. 1989 Feb;89(2):700–706. doi: 10.1104/pp.89.2.700. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Fett W. F., Dunn M. F. Exopolysaccharides Produced by Phytopathogenic Pseudomonas syringae Pathovars in Infected Leaves of Susceptible Hosts. Plant Physiol. 1989 Jan;89(1):5–9. doi: 10.1104/pp.89.1.5. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Grill E., Löffler S., Winnacker E. L., Zenk M. H. Phytochelatins, the heavy-metal-binding peptides of plants, are synthesized from glutathione by a specific gamma-glutamylcysteine dipeptidyl transpeptidase (phytochelatin synthase). Proc Natl Acad Sci U S A. 1989 Sep;86(18):6838–6842. doi: 10.1073/pnas.86.18.6838. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Grill E., Winnacker E. L., Zenk M. H. Phytochelatins, a class of heavy-metal-binding peptides from plants, are functionally analogous to metallothioneins. Proc Natl Acad Sci U S A. 1987 Jan;84(2):439–443. doi: 10.1073/pnas.84.2.439. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Jackson P. J., Unkefer C. J., Doolen J. A., Watt K., Robinson N. J. Poly(gamma-glutamylcysteinyl)glycine: its role in cadmium resistance in plant cells. Proc Natl Acad Sci U S A. 1987 Oct;84(19):6619–6623. doi: 10.1073/pnas.84.19.6619. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Mutoh N., Hayashi Y. Isolation of mutants of Schizosaccharomyces pombe unable to synthesize cadystin, small cadmium-binding peptides. Biochem Biophys Res Commun. 1988 Feb 29;151(1):32–39. doi: 10.1016/0006-291x(88)90555-4. [DOI] [PubMed] [Google Scholar]
  9. Newton G. L., Dorian R., Fahey R. C. Analysis of biological thiols: derivatization with monobromobimane and separation by reverse-phase high-performance liquid chromatography. Anal Biochem. 1981 Jul 1;114(2):383–387. doi: 10.1016/0003-2697(81)90498-x. [DOI] [PubMed] [Google Scholar]
  10. Nussbaum S., Schmutz D., Brunold C. Regulation of Assimilatory Sulfate Reduction by Cadmium in Zea mays L. Plant Physiol. 1988 Dec;88(4):1407–1410. doi: 10.1104/pp.88.4.1407. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Rauser W. E. Phytochelatins. Annu Rev Biochem. 1990;59:61–86. doi: 10.1146/annurev.bi.59.070190.000425. [DOI] [PubMed] [Google Scholar]
  12. Rauser W. E., Schupp R., Rennenberg H. Cysteine, gamma-Glutamylcysteine, and Glutathione Levels in Maize Seedlings : Distribution and Translocation in Normal and Cadmium-Exposed Plants. Plant Physiol. 1991 Sep;97(1):128–138. doi: 10.1104/pp.97.1.128. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Reese R. N., Wagner G. J. Effects of buthionine sulfoximine on cd-binding Peptide levels in suspension-cultured tobacco cells treated with cd, zn, or cu. Plant Physiol. 1987 Jul;84(3):574–577. doi: 10.1104/pp.84.3.574. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Rüegsegger A., Schmutz D., Brunold C. Regulation of Glutathione Synthesis by Cadmium in Pisum sativum L. Plant Physiol. 1990 Aug;93(4):1579–1584. doi: 10.1104/pp.93.4.1579. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Scheller H. V., Huang B., Hatch E., Goldsbrough P. B. Phytochelatin synthesis and glutathione levels in response to heavy metals in tomato cells. Plant Physiol. 1987 Dec;85(4):1031–1035. doi: 10.1104/pp.85.4.1031. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Steffens J. C., Hunt D. F., Williams B. G. Accumulation of non-protein metal-binding polypeptides (gamma-glutamyl-cysteinyl)n-glycine in selected cadmium-resistant tomato cells. J Biol Chem. 1986 Oct 25;261(30):13879–13882. [PubMed] [Google Scholar]
  17. Yoshimura E., Kabuyama Y., Yamazaki S., Toda S. Activity of poly(gamma-glutamylcysteinyl)glycine synthesis in crude extract of fission yeast, Schizosaccharomyces pombe. Agric Biol Chem. 1990 Nov;54(11):3025–3026. [PubMed] [Google Scholar]

Articles from Plant Physiology are provided here courtesy of Oxford University Press

RESOURCES