Abstract
Nitrogenase activities, measured by acetylene reduction, were detected under microaerophilic field conditions in Douglas-fir tuberculate ectomycorrhizae. Tuberculate ectomycorrhizae consist of densely packed clusters of ectomycorrhizal rootlets enclosed in a supplementary fungal peridium-like layer. Nitrogenase activity was primarily in the external layer and was greatly enhanced with added sucrose. The bacterium isolated, a nitrogen-fixing, spore-forming Bacillus sp., is an aerobe but requires anaerobic conditions for nitrogenase activity. Respiration in the tuberculate complex by the fungus, roots, and associated mycorrhizosphere microbes probably contributes to maintaining a microaerophilic niche where nitrogen fixation can take place. Water extracts of peridium or mycorrhizal root tips enhanced nitrogenase activity of this associative Bacillus sp., thereby indicating a close nutritional relationship between this bacterium and the tuberculate mycorrhizae. Thiamine more significantly enhanced bacterial nitrogenase activity than biotin; no activity was detected with p-aminobenzoic acid. Even though the levels ofnitrogenase activities in the tubercles in situ were low, as measured by the present methods, they may indicate a significant contribution to the nitrogen dynamics of these nitrogen-limited Douglas-fir forests over a long-term period.
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References
Amaranthus, M P, Li, C Y and Perry, D A 1990 Influence of vegetation type and madrone soil inoculum on associative nitrogen fixation in Douglas-fir rhizospheres. Can. J. For. Res. 20, 368–371.
Dell, B, Malajczuk, N and Thompson, G T 1990 Ectomycorrhiza formation in Eucalyptus. V. A tuberculate ectomycorrhiza of Eucalyptus pilularis. New Phytol. 114, 633–640.
Dominik, T 1963 Mikotrofizm daglezji (Pseudotsuga taxifolia Britton) w roznych drzewostanach w Polsce. Inst. Bad. Lesn. Prace 258, 29–59.
Harvey, A E, Larsen, M J, Jurgensen, M F and Jones, E A 1989 Nitrogenase activity associated with decayed wood of living northern Idaho conifers. Mycologia 81, 765–771.
Holdeman, L V, Cato, E P and Moore, W E C (Eds.) 1977 Anaerobe laboratory manual, 4th ed. Virginia Polytechnic Institute and State University, Blacksburg.
Jurgensen, M F, Larsen, M J, Wolosiewicz, M and Harvey, A E 1989 A comparison of dinitrogen fixation rates in wood litter decayed by white-rot and brown-rot fungi. Plant and Soil 115, 117–122.
Larsen, M J, Jurgensen, M F and Harvey, A E 1978 N2 fixation associated with wood decayed by some common fungi in western Montana. Can. J. For. Res. 8, 341–345.
Li, C Y and Castellano, M A 1984 Dinitrogen-fixing bacteria isolated from the interior of three ectomycorrhizal sporocarps. In Proc. 6th N. Am. Conf. on Mycorrhizae. Ed. R Molina. Forestry Research Laboratory, Oregon State University, Corvallis. 264 p.
Li, C Y and Hung, L L 1987 Nitrogen-fixing (acetylene-reducing) bacteria associated with ectomycorrhizae. Plant and Soil 98, 425–428.
Masui, K 1926 The compound mycorrhiza of Quercus pausidentata. Mem. Coll. Sci. Kyoto Imp. Univ. Ser. B 2, 161–187.
Melin, E 1923 Experimentelle Untersuchungen über die Konstitution und Ökologie der Mykorrhizen von Pinus sylvestris L. und Picea abies (L.) Karst. Mykologische Untersuch. und Ber. 2, 73–331.
Moore, L V H, Johnson, J L and Moore, W E C 1987 Selenomonas noxia sp. nov., Selenomonas flueggei sp. nov., Selenomonas infelix sp. nov., Selenomonas dianae sp. nov., and Selenomonas artemidis sp. nov., from the human gingival crevice. Int. J. Syst. Bacteriol. 36, 271–280.
Moore, W E C, Hash, D E, Holdeman, L V and Cato, E P 1980 Polyacrylamide slab gel clectrophoresis of soluble proteins for studies of bacterial floras. Appl. Environ. Microbiol. 39, 900–907.
Pachlewski R, Kermen J, Chrusciak E and Trzcinska M 1992 Studies on pine ectendomycorrhizae in nurseries. Acta Mycol. In press.
Randall, B L and Grand, L F 1986 Morphology and possible mycobiont (Suillus pictus) of a tuberculate ectomycorrhiza on Pinus strobus. Can. J. Bot. 64, 2182–2191.
Sabin, T E and Stafford, S G 1990 Assessing the need for transformation of response variables. Forestry Research Laboratory, Oregon State University, Corvallis. Special Publication 20. 31 p.
Silvester, W B, Sollins, P, Verhoeven, T and Cline, S P 1982 Nitrogen fixation and acetylene reduction in decaying conifer boles: Effects of incubation time, aeration, and moisture content. Can. J. For. Res. 12, 646–652.
Stowers, D M 1987 Collection, isolation, cultivation, and maintenance of associative N2-fixing Frankia. In Symbiotic Nitrogen Fixation Technology. Ed. G H Elkan. Pp 29–53. Marcel Dekker, Inc., New York.
Trappe, J M 1965 Tuberculate mycorrhizae of Douglas-fir. For. Sci. 11, 27–32.
Zak, B 1971 Characterization and classification of mycorrhizae of Douglas-fir. II. Pseudotsuga menziesii + Rhizopogon vinicolor. Can. J. Bot. 49, 1079–1084.
Zuberer, D A 1987 Collection, isolation, cultivation, and maintenance of associative N2-fixing bacteria. In Symbiotic Nitrogen Fixation Technology. Ed. G H Elkan. pp 95–125. Marcel Dekker, Inc., New York.
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Li, C.Y., Massicote, H.B. & Moore, L.V.H. Nitrogen-fixing Bacillus sp. associated with Douglas-fir tuberculate ectomycorrhizae. Plant Soil 140, 35–40 (1992). https://doi.org/10.1007/BF00012804
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DOI: https://doi.org/10.1007/BF00012804