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. 1995 Nov;109(3):945–954. doi: 10.1104/pp.109.3.945

Comparison of metallothionein gene expression and nonprotein thiols in ten Arabidopsis ecotypes. Correlation with copper tolerance.

A Murphy 1, L Taiz 1
PMCID: PMC161396  PMID: 8552721

Abstract

Seedlings of 10 Arabidopsis ecotypes were compared with respect to copper tolerance, expression of two metallothionein genes (MT1 and MT2), and nonprotein thiol levels. MT1 was uniformly expressed in all treatments, and MT2 was copper inducible in all 10 ecotypes. MT1 and MT2 mRNA levels were compared with various growth parameters for the 10 ecotypes in the presence of 40 microM Cu2+. The best correlation (R = 0.99) was obtained between MT2 mRNA and the rate of root extension. MT2 mRNA levels also paralleled the recovery phase following inhibition by copper. Induction of MT2 mRNA was initiated at copper concentrations below the threshold for growth inhibition. In cross-induction experiments, Ag+, Cd2+, Zn2+, Ni2+, and heat shock all induced significant levels of MT2 gene expression, whereas Al3+ and salicylic acid did not. The correlation between copper tolerance and nonprotein thiol levels in the 10 ecotypes was not statistically significant. However, 2 ecotypes, Ws and Enkheim, previously shown to exhibit an acclimation response, had the highest levels of nonprotein thiols. We conclude that MT2 gene expression may be the primary determinant of ecotypic differences in the copper tolerance of nonpretreated Arabidopsis seedlings.

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Selected References

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  1. Beltramini M., Lerch K. Primary structure and spectroscopic studies of Neurospora copper metallothionein. Environ Health Perspect. 1986 Mar;65:21–27. doi: 10.1289/ehp.866521. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Evans K. M., Gatehouse J. A., Lindsay W. P., Shi J., Tommey A. M., Robinson N. J. Expression of the pea metallothionein-like gene PsMTA in Escherichia coli and Arabidopsis thaliana and analysis of trace metal ion accumulation: implications for PsMTA function. Plant Mol Biol. 1992 Dec;20(6):1019–1028. doi: 10.1007/BF00028889. [DOI] [PubMed] [Google Scholar]
  3. Gupta S. C., Goldsbrough P. B. Phytochelatin accumulation and cadmium tolerance in selected tomato cell lines. Plant Physiol. 1991 Sep;97(1):306–312. doi: 10.1104/pp.97.1.306. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Hamer D. H. Metallothionein. Annu Rev Biochem. 1986;55:913–951. doi: 10.1146/annurev.bi.55.070186.004405. [DOI] [PubMed] [Google Scholar]
  5. Harmens H., Den Hartog P. R., Bookum WMT., Verkleij JAC. Increased Zinc Tolerance in Silene vulgaris (Moench) Garcke Is Not Due to Increased Production of Phytochelatins. Plant Physiol. 1993 Dec;103(4):1305–1309. doi: 10.1104/pp.103.4.1305. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Hottiger T., Fürst P., Pohlig G., Heim J. Physiological characterization of the yeast metallothionein (CUP1) promoter, and consequences of overexpressing its transcriptional activator, ACE1. Yeast. 1994 Mar;10(3):283–296. doi: 10.1002/yea.320100302. [DOI] [PubMed] [Google Scholar]
  7. Howden R., Cobbett C. S. Cadmium-Sensitive Mutants of Arabidopsis thaliana. Plant Physiol. 1992 Sep;100(1):100–107. doi: 10.1104/pp.100.1.100. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Murphy A., Taiz L. A New Vertical Mesh Transfer Technique for Metal-Tolerance Studies in Arabidopsis (Ecotypic Variation and Copper-Sensitive Mutants). Plant Physiol. 1995 May;108(1):29–38. doi: 10.1104/pp.108.1.29. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Münger K., Germann U. A., Lerch K. Isolation and structural organization of the Neurospora crassa copper metallothionein gene. EMBO J. 1985 Oct;4(10):2665–2668. doi: 10.1002/j.1460-2075.1985.tb03985.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Nriagu J. O., Pacyna J. M. Quantitative assessment of worldwide contamination of air, water and soils by trace metals. Nature. 1988 May 12;333(6169):134–139. doi: 10.1038/333134a0. [DOI] [PubMed] [Google Scholar]
  11. Ortiz D. F., Ruscitti T., McCue K. F., Ow D. W. Transport of metal-binding peptides by HMT1, a fission yeast ABC-type vacuolar membrane protein. J Biol Chem. 1995 Mar 3;270(9):4721–4728. doi: 10.1074/jbc.270.9.4721. [DOI] [PubMed] [Google Scholar]
  12. Presta A., Stillman M. J. Chiral copper(I)-thiolate clusters in metallothionein and glutathione. Chirality. 1994;6(7):521–530. doi: 10.1002/chir.530060703. [DOI] [PubMed] [Google Scholar]
  13. Rauser W. E. Phytochelatins. Annu Rev Biochem. 1990;59:61–86. doi: 10.1146/annurev.bi.59.070190.000425. [DOI] [PubMed] [Google Scholar]
  14. Robinson N. J., Tommey A. M., Kuske C., Jackson P. J. Plant metallothioneins. Biochem J. 1993 Oct 1;295(Pt 1):1–10. doi: 10.1042/bj2950001. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Schat H., Kalff M. M. Are phytochelatins involved in differential metal tolerance or do they merely reflect metal-imposed strain? Plant Physiol. 1992 Aug;99(4):1475–1480. doi: 10.1104/pp.99.4.1475. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Silar P., Butler G., Thiele D. J. Heat shock transcription factor activates transcription of the yeast metallothionein gene. Mol Cell Biol. 1991 Mar;11(3):1232–1238. doi: 10.1128/mcb.11.3.1232. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Snustad D. P., Haas N. A., Kopczak S. D., Silflow C. D. The small genome of Arabidopsis contains at least nine expressed beta-tubulin genes. Plant Cell. 1992 May;4(5):549–556. doi: 10.1105/tpc.4.5.549. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Vögeli-Lange R., Wagner G. J. Subcellular localization of cadmium and cadmium-binding peptides in tobacco leaves : implication of a transport function for cadmium-binding peptides. Plant Physiol. 1990 Apr;92(4):1086–1093. doi: 10.1104/pp.92.4.1086. [DOI] [PMC free article] [PubMed] [Google Scholar]

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