Abstract
Soybean plants (Glycine max [L.] Merr) were grown in sand culture with 2 millimolar nitrate for 37 days and then supplied with 15 millimolar nitrate for 7 days. Control plants received 2 millimolar nitrate and 13 millimolar chloride and, after the 7-day treatment period, all plants were supplied with nil nitrate. The temporary treatment with high nitrate inhibited nitrogenase (acetylene reduction) activity by 80% whether or not Rhizobium japonicum bacteroids had nitrate reductase (NR) activity. The pattern of nitrite accumulation in nodules formed by NR+ rhizobia was inversely related to the decrease and recovery of nitrogenase activity. However, nitrite concentration in nodules formed by NR− rhizobia appeared to be too low to explain the inhibition of nitrogenase. Carbohydrate composition was similar in control nodules and nodules receiving 15 millimolar nitrate suggesting that the inhibition of nitrogenase by nitrate was not related to the availability of carbohydrate.
Nodules on plants treated with 15 millimolar nitrate contained higher concentrations of amino N and, especially, ureide N than control nodules and, after withdrawal of nitrate, reduced N content of treated and control nodules returned to similar levels. The accumulation of N2 fixation products in nodules in response to high nitrate treatment was observed with three R. japonicum strains, two NR+ and one NR−. The high nitrate treatment did not affect the allantoate/allantoin ratio or the proportion of amino N or ureide N in bacteroids (4%) and cytosol (96%).
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Selected References
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- Atkins C. A., Ritchie A., Rowe P. B., McCairns E., Sauer D. De Novo Purine Synthesis in Nitrogen-Fixing Nodules of Cowpea (Vigna unguiculata [L.] Walp.) and Soybean (Glycine max [L.] Merr.). Plant Physiol. 1982 Jul;70(1):55–60. doi: 10.1104/pp.70.1.55. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Huber T. A., Streeter J. G. Asparagine biosynthesis in soybean nodules. Plant Physiol. 1984 Mar;74(3):605–610. doi: 10.1104/pp.74.3.605. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Manhart J. R., Wong P. P. Nitrate Effect on Nitrogen Fixation (Acetylene Reduction): ACTIVITIES OF LEGUME ROOT NODULES INDUCED BY RHIZOBIA WITH VARIED NITRATE REDUCTASE ACTIVITIES. Plant Physiol. 1980 Mar;65(3):502–505. doi: 10.1104/pp.65.3.502. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Noel K. D., Carneol M., Brill W. J. Nodule protein synthesis and nitrogenase activity of soybeans exposed to fixed nitrogen. Plant Physiol. 1982 Nov;70(5):1236–1241. doi: 10.1104/pp.70.5.1236. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Reynolds P. H., Boland M. J., Blevins D. G., Schubert K. R., Randall D. D. Enzymes of amide and ureide biogenesis in developing soybean nodules. Plant Physiol. 1982 Jun;69(6):1334–1338. doi: 10.1104/pp.69.6.1334. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Stephens B. D., Neyra C. A. Nitrate and Nitrite Reduction in Relation to Nitrogenase Activity in Soybean Nodules and Rhizobium japonicum Bacteroids. Plant Physiol. 1983 Apr;71(4):731–735. doi: 10.1104/pp.71.4.731. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Streeter J. G., Devine P. J. Evaluation of Nitrate Reductase Activity in Rhizobium japonicum. Appl Environ Microbiol. 1983 Aug;46(2):521–524. doi: 10.1128/aem.46.2.521-524.1983. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Streeter J. G. Effect of nitrate in the rooting medium on carbohydrate composition of soybean nodules. Plant Physiol. 1981 Oct;68(4):840–844. doi: 10.1104/pp.68.4.840. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Streeter J. G. Nitrate inhibition of legume nodule growth and activity : I. Long term studies with a continuous supply of nitrate. Plant Physiol. 1985 Feb;77(2):321–324. doi: 10.1104/pp.77.2.321. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Streeter J. G. Synthesis and accumulation of nitrite in soybean nodules supplied with nitrate. Plant Physiol. 1982 Jun;69(6):1429–1434. doi: 10.1104/pp.69.6.1429. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wong P. P. Nitrate and Carbohydrate Effects on Nodulation and Nitrogen Fixation (Acetylene Reduction) Activity of Lentil (Lens esculenta Moench). Plant Physiol. 1980 Jul;66(1):78–81. doi: 10.1104/pp.66.1.78. [DOI] [PMC free article] [PubMed] [Google Scholar]
