The development of bacteroids in alfalfa (Medicago sativa) nodules

dc.contributor.advisorCowles, Joe R.
dc.contributor.committeeMemberHendrix, Donald L.
dc.contributor.committeeMemberGray, Horace B., Jr.
dc.contributor.committeeMemberJurtshuk, Peter, Jr.
dc.creatorPaau, Alan Shiu Kee
dc.description.abstractDNA-dependent DNA polymerase was purified to near homogeneity from extracts of cultured Rhizobium meliloti F28. The enzyme required the presence of a full complement of deoxyribonucleoside triphosphates, Mg++ or Mn++, and DNA primer-template for maximum activity. The enzyme was also sensitive to p-chloromercuribenzoate and N-ethylmaleimide. The process of development and transformation of R. meliloti F28 in nodules of alfalfa (Medicago sativa Buffalo) into symbiotic bacteroids and the associated development of symbiotic dinitrogen fixation and leghemoglobin in alfalfa nodules were studied with the use of light and electron microscopy, gas-chromatography, and flowmicrofluorometry. Inside the nodules, the rhizobia developed into matured bacteroids which were enlarged and had higher nucleic acid content than the cultured rhizobia. These bacteroids were active in nitrogenase activity and had altered nucleoid structures. Bacteroid senescence was accompanied by a loss in the bacteroid nucleic acid content and nitrogenase activity of the nodules. A model was constructed to describe the process of bacteroid development and transformation in alfalfa nodules. The applicability of the flow-microfluorometry to the studies of bacterial and algal cell and isolated chloroplasts was also examined.
dc.description.departmentBiology and Biochemistry, Department of
dc.format.digitalOriginreformatted digital
dc.rightsThis item is protected by copyright but is made available here under a claim of fair use (17 U.S.C. Section 107) for non-profit research and educational purposes. Users of this work assume the responsibility for determining copyright status prior to reusing, publishing, or reproducing this item for purposes other than what is allowed by fair use or other copyright exemptions. Any reuse of this item in excess of fair use or other copyright exemptions requires express permission of the copyright holder.
dc.titleThe development of bacteroids in alfalfa (Medicago sativa) nodules
dc.type.genreThesis of Natural Sciences and Mathematics, Department of of Houston of Philosophy


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