Copy of author's previously published work inserted. Bibliography: leaves 114-136. The study concentrates on: investigation of the biological properties and role of agrocin 434 and other factors in the bicontrol process of crown gall disease; isolation of the complete range of K84 derivatives carrying different combinations of plasmids pAgK84, pAgK434 and pAtK84b in the same host background; development of a rapid plant bioassay to assess the efficacy of biocontrol strains by leaf disc tumorigenesis assay; and characterization of agrocin 434 synthesis and immunity genes.

Thesis (Ph. D.)--University of Washington, 1983. / Vita. Bibliography: leaves [118]-133.

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The purposes of this study were to determine the effect of the exogenous polyamines, spermidine and spermidine, on growth of crown gall tumors, to assay levels of spermidine and spermine in normal and crown gall tumor tissue and to determine the effects of selected anti-tumor compounds on growth of crown gall tumors as well as on the endogenous levels of the polyamines in those tumors.Findings1. Spermidine and spermine are present in normal potato tissue and crown gall tumor tissue grown on potato discs.2. Exogenous spermidine and spermine do affect growth of crown gall tumors depending upon the concentration of the solutions added, the type of polyamine added and the number of times the solutions are applied.3. Spermidine (1 mM) has a positive growth effect on crown gall tumors.4. Crown gall tumor tissue contains more spermidine than corresponding normal potato tissue; spermine levels are consistently low compared to spermidine levels in both crown gall tissue and normal potato tissue.5. The level of spermidine in tumor tissue increases as the tumors develop; the level of spermine remains consistently low.6. Addition of methylglyoxal bis (guanylyhdrazone) inhibits tumor growth, but the inhibitory effect is decreased by concurrent administration of spermidine.7. Both novobiocin and nalidixic acid have an inhibitory effect on tumor growth, but the effects are decreased by concurrent administration of spermidine. Reversal of the nalidixic acid effect on growth by addition of spermidine is more pronounced than reversal of the novobiocin effect.8. Methylglyoxal bis (guanylhydrazone) decreases the endogenous levels of both spermidine and spermine in crown gall tumor tissue.Conclusions1. The polyamine, spermidine, plays an important role in the growth of crown gall tumors.2. Compounds which inhibit spermidine biosynthesis or the possible mode of action of spermidine inhibit tumor growth.3. Other polyamines appear to have no significant role in crown gall tumor growth.4. The growth of crown gall tumors involves the activation of a mechanism leading to the increased biosynthesis of spermidine.5. A specific inhibitor of polyamine biosynthesis in animals also reduces endogenous levels of spermidine and spermine in crown gall tumors.6. These data further support the hypothesis that crown gall tumors are similar to animal tumors.

Copies of author's previously published articles inserted. / Bibliography: leaves 72-90. / vii, 101, [28] leaves, [12] leaves of plates : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Crown gall is a plant cancer caused by pathogenic strains of Agrobacterium, a soil microorganism belonging to the family Rhizobiaceae. This thesis examines the possible role in the biological control process, of an antibiotic compound agrocin 434, produced by biocontrol strains, in addition to the well-characterized adenine nucleotide, agrocin 84. / Thesis (Ph.D.)--University of Adelaide, Dept. of Crop Protection and Plant Science, 1996

Copy of author's previously published work inserted. / Bibliography: leaves 114-136. / xiv, 144, [19] leaves, [18] leaves of plates : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / The study concentrates on: investigation of the biological properties and role of agrocin 434 and other factors in the bicontrol process of crown gall disease; isolation of the complete range of K84 derivatives carrying different combinations of plasmids pAgK84, pAgK434 and pAtK84b in the same host background; development of a rapid plant bioassay to assess the efficacy of biocontrol strains by leaf disc tumorigenesis assay; and characterization of agrocin 434 synthesis and immunity genes. / Thesis (Ph.D.)--University of Adelaide, Dept. of Crop Protection, 1997

Bibliography: leaves 90-100. / viii, 100, [91] leaves, [7] leaves of plates : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This study is concerned with the chemistry of several biologically active, toxic molecules produced by Agrobacteria. It centres upon the discovery and structural analysis of a previously unknown antibiotic substance known as agrocin 434. This agrocin is produced by A. rhizogenes (formerly "radiobacter") strain K84, the biological control agent of crown gall. / Thesis (Ph.D.)--University of Adelaide, Dept. of Plant Science, 1997

Bibliography: leaves 90-100. / viii, 100, [91] leaves, [7] leaves of plates : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This study is concerned with the chemistry of several biologically active, toxic molecules produced by Agrobacteria. It centres upon the discovery and structural analysis of a previously unknown antibiotic substance known as agrocin 434. This agrocin is produced by A. rhizogenes (formerly "radiobacter") strain K84, the biological control agent of crown gall. / Thesis (Ph.D.)--University of Adelaide, Dept. of Plant Science, 1997