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. 1992 Mar;98(3):942–948. doi: 10.1104/pp.98.3.942

Urease-Null and Hydrogenase-Null Phenotypes of a Phylloplane Bacterium Reveal Altered Nickel Metabolism in Two Soybean Mutants 1

Mark A Holland 1,2, Joseph C Polacco 1,2
PMCID: PMC1080291  PMID: 16668768

Abstract

Mutation at either of two genetic loci (Eu2 or Eu3) in soybean (Glycine max [L.] Merr.) results in a pleiotropic elimination of the activity of both major urease isozymes. Surprisingly, the phenotype of a phylloplane bacterium, Methylobacterium mesophilicum, living on the leaves of eu2/eu2 or eu3-e1/eu3-e1 mutants is also affected by these plant mutations. The bacteria isolated from leaves of these soybean mutants have transient urease- and hydrogenase-deficient phenotypes that can be corrected by the addition of nickel to free-living cultures. The same bacterium growing on wild-type soybeans or on urease mutants eu1-sun/eu1-sun or eu4/eu4, each deficient in only one urease isozyme, are urease-positive. These results suggest that the bacterium living on the eu2/eu2 or eu3-e1/eu3-e1 mutant is unable to produce an active urease or hydrogenase because it is effectively starved for nickel. We infer that mutations at Eu2 or Eu3 result in defects in nickel metabolism but not in Ni2+ uptake or transport, because eu2/eu2 and eu3-e1/eu3-e1 mutants exhibit normal uptake of 63NiCl2. Moreover, wild-type plants grafted on mutant rootstocks produce seeds with fully active urease, indicating unimpeded transport of nickel through mutant roots and stems.

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Selected References

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

  1. Cataldo D. A., Garland T. R., Wildung R. E. Nickel in Plants: II. Distribution and Chemical Form in Soybean Plants. Plant Physiol. 1978 Oct;62(4):566–570. doi: 10.1104/pp.62.4.566. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Cataldo D. A., Garland T. R., Wildung R. E. Nickel in plants: I. Uptake kinetics using intact soybean seedlings. Plant Physiol. 1978 Oct;62(4):563–565. doi: 10.1104/pp.62.4.563. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Eskew D. L., Welch R. M., Cary E. E. Nickel: an essential micronutrient for legumes and possibly all higher plants. Science. 1983 Nov 11;222(4624):621–623. doi: 10.1126/science.222.4624.621. [DOI] [PubMed] [Google Scholar]
  4. Haugland R. A., Hanus F. J., Cantrell M. A., Evans H. J. Rapid Colony Screening Method for Identifying Hydrogenase Activity in Rhizobium japonicum. Appl Environ Microbiol. 1983 Mar;45(3):892–897. doi: 10.1128/aem.45.3.892-897.1983. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Hood D. W., Dow C. S., Green P. N. DNA:DNA hybridization studies on the pink-pigmented facultative methylotrophs. J Gen Microbiol. 1987 Mar;133(3):709–720. doi: 10.1099/00221287-133-3-709. [DOI] [PubMed] [Google Scholar]
  6. Meyer-Bothling L E, Polacco J C, Cianzio S R. Pleiotropic soybean mutants defective in both urease isozymes. Mol Gen Genet. 1987 Oct;209(3):432–438. doi: 10.1007/BF00331146. [DOI] [PubMed] [Google Scholar]
  7. Meyer-Bothling L E, Polacco J C. Mutational analysis of the embryo-specific urease locus of soybean. Mol Gen Genet. 1987 Oct;209(3):439–444. doi: 10.1007/BF00331147. [DOI] [PubMed] [Google Scholar]
  8. Mulrooney S. B., Hausinger R. P. Sequence of the Klebsiella aerogenes urease genes and evidence for accessory proteins facilitating nickel incorporation. J Bacteriol. 1990 Oct;172(10):5837–5843. doi: 10.1128/jb.172.10.5837-5843.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Polacco J. C. Nitrogen metabolism in soybean tissue culture: I. Assimilation of urea. Plant Physiol. 1976 Sep;58(3):350–357. doi: 10.1104/pp.58.3.350. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Polacco J. C., Winkler R. G. Soybean leaf urease: a seed enzyme? Plant Physiol. 1984 Apr;74(4):800–803. doi: 10.1104/pp.74.4.800. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Stebbins N., Holland M. A., Cianzio S. R., Polacco J. C. Genetic tests of the roles of the embryonic ureases of soybean. Plant Physiol. 1991 Nov;97(3):1004–1010. doi: 10.1104/pp.97.3.1004. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Walsh C. T., Orme-Johnson W. H. Nickel enzymes. Biochemistry. 1987 Aug 11;26(16):4901–4906. doi: 10.1021/bi00390a001. [DOI] [PubMed] [Google Scholar]
  13. White M. C. Metal Complexation in Xylem Fluid : III. ELECTROPHORETIC EVIDENCE. Plant Physiol. 1981 Feb;67(2):311–315. doi: 10.1104/pp.67.2.311. [DOI] [PMC free article] [PubMed] [Google Scholar]

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