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. 1991 Apr;95(4):1106–1112. doi: 10.1104/pp.95.4.1106

Effect of Localized Nitrate Application on Isoflavonoid Concentration and Nodulation in Split-Root Systems of Wild-Type and Nodulation-Mutant Soybean Plants 1

Myeong-Je Cho 1,2, James E Harper 1,2
PMCID: PMC1077658  PMID: 16668097

Abstract

Although isoflavonoids are known to be inducers of nod genes in Bradyrhizobium japonicum, it was recently proposed that internal root levels of isoflavonoids may be important in nodule development on soybean (Glycine max [L.] Merr.). The hypernodulating soybean mutants were shown to accumulate higher root concentrations of isoflavonoid compounds (daidzein, genistein, and coumestrol) and to be more extensively nodulated than was the Williams parent when inoculated with B. japonicum. The hypernodulating mutants and the parent line, Williams, also showed decreased isoflavonoid concentrations and decreased nodule development if N was applied. The current study evaluated the effect of localized NO3− application on root isoflavonoid concentration and on nodulation in split-root systems of the Williams wild type and a hypernodulating mutant (NOD1-3). Nitrate application markedly decreased isoflavonoid concentrations in non-inoculated soybean roots. When roots were inoculated, nodule number, weight, and nitrogenase activity were markedly suppressed on the root-half receiving 5 millimolar NO3− compared with the other root-half receiving 0 millimolar NO3−. High performance liquid chromatographic analyses of root extracts showed that the root-half receiving 5 millimolar NO3− was markedly lower in isoflavonoid concentrations in both soybean lines. This was partially due to the localized stimulatory effect of NO3− on root growth. The inoculated NOD1-3 mutant had higher isoflavonoid concentrations than did the Williams control in both the presence and absence of NO3−. These results provide evidence that the site of N application primarily controls the site of nodulation inhibition, possibly through decreasing isoflavonoid levels. Although the effect of NO3− on nodule development and root isoflavonoid concentration was strongly localized, there was evidence that NO3− also resulted in a systemic effect on root isoflavonoids. The results are consistent with previous speculation that internal levels of root isoflavonoids may affect nodule development.

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Selected References

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

  1. Cho M. J., Harper J. E. Effect of inoculation and nitrogen on isoflavonoid concentration in wild-type and nodulation-mutant soybean roots. Plant Physiol. 1991 Feb;95(2):435–442. doi: 10.1104/pp.95.2.435. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Djordjevic M. A., Redmond J. W., Batley M., Rolfe B. G. Clovers secrete specific phenolic compounds which either stimulate or repress nod gene expression in Rhizobium trifolii. EMBO J. 1987 May;6(5):1173–1179. doi: 10.1002/j.1460-2075.1987.tb02351.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Gremaud M. F., Harper J. E. Selection and initial characterization of partially nitrate tolerant nodulation mutants of soybean. Plant Physiol. 1989 Jan;89(1):169–173. doi: 10.1104/pp.89.1.169. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Kosslak R. M., Bohlool B. B. Suppression of nodule development of one side of a split-root system of soybeans caused by prior inoculation of the other side. Plant Physiol. 1984 May;75(1):125–130. doi: 10.1104/pp.75.1.125. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Kosslak R. M., Bookland R., Barkei J., Paaren H. E., Appelbaum E. R. Induction of Bradyrhizobium japonicum common nod genes by isoflavones isolated from Glycine max. Proc Natl Acad Sci U S A. 1987 Nov;84(21):7428–7432. doi: 10.1073/pnas.84.21.7428. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. McNeil D. L. Variations in Ability of Rhizobium japonicum Strains To Nodulate Soybeans and Maintain Fixation in the Presence of Nitrate. Appl Environ Microbiol. 1982 Sep;44(3):647–652. doi: 10.1128/aem.44.3.647-652.1982. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Olsson J. E., Nakao P., Bohlool B. B., Gresshoff P. M. Lack of Systemic Suppression of Nodulation in Split Root Systems of Supernodulating Soybean (Glycine max [L.] Merr.) Mutants. Plant Physiol. 1989 Aug;90(4):1347–1352. doi: 10.1104/pp.90.4.1347. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Peters N. K., Frost J. W., Long S. R. A plant flavone, luteolin, induces expression of Rhizobium meliloti nodulation genes. Science. 1986 Aug 29;233(4767):977–980. doi: 10.1126/science.3738520. [DOI] [PubMed] [Google Scholar]
  9. Pierce M., Bauer W. D. A rapid regulatory response governing nodulation in soybean. Plant Physiol. 1983 Oct;73(2):286–290. doi: 10.1104/pp.73.2.286. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Singleton P. W., van Kessel C. Effect of localized nitrogen availability to soybean half-root systems on photosynthate partitioning to roots and nodules. Plant Physiol. 1987 Mar;83(3):552–556. doi: 10.1104/pp.83.3.552. [DOI] [PMC free article] [PubMed] [Google Scholar]

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