The mycoparasite Stachybotrys elegans represents a potential biocontrol agent of Rhizoctonia solani, the causal organism of potato stem canker. The differential expression of two mycoparasitism-induced genes was monitored in S. elegans during interactions with its host, Rhizoctonia solani, and a non-host, Sclerotinia sclerotiorum. Using real-time reverse-transcription polymerase chain reaction (QRT-PCR), comparative analyses demonstrated that hyphal and sclerotial forms triggered different patterns of gene expression in the mycoparasite, as did the presence of the host or non-host. The calmodulin gene did not appear to be involved in conidial germination or appressoria formation of S. elegans. Potential roles of calmodulin during mycoparasitism are suggested, but further studies are required. The expression of the endochitinase-encoding gene, sechi44, was susbstantial only at later stages of interaction with living host sclerotia. Host defense mechanisms probably play a role in regulating sechi44 expression. Knowledge of the genetic mechanisms underlying this mycoparasitic relationship will further our knowledge on the potential use of S. elegans in biocontrol strategies. / Le mycoparasite Stachybotrys elegans est un agent potentiel de lutte biologiquepour le contrôle de Rhizoctonia solani, un phytopathogène causant le chancre dela tige et des stolons chez la pomme de terre (Solanum tuberosum). L'expressionde deux gènes induits pendant le mycoparasitisme a été étudiée chez S. elegans,alors que le mycoparasite était en interaction avec son hôte, R. solani, et un nonhôte,Sclerotinia sclerotiorum en utilisant la PCR quantitative en temps réel. Desanalyses comparatives ont démontré que les différentes formes d'hyphes et desc1érotes, ainsi que la présence de l'hôte ou du non-hôte, induisent différentspatrons d'expression. Le gène codant pour la calmodulin (calmodulin) ne semblepas être impliqué dans la germination des conidia ou dans la formation desappressoria chez S. elegans. Des rôles possibles de calmodulin sont suggérés,mais des études plus poussées demeurent nécessaires. L'expression du gènesechi44, codant pour une endochitinase, est importante dans des stades plusavancés du mycoparasitisme sur les sc1érotes vivants de 1 'hôte. Des mécanismesde défense de l'hôte jouent probablement un rôle important dans la régulation del'expression de sechi44. Une meilleure connaissance de la régulation génétiquelors du mycoparasitisme pourrait nous aider à évaluer le potentiel de S. elegansdans des stratégies de biocontrôle.

Serratia entomophila, the causative agent of amber disease, is an endemic bacterium used for the biocontrol of New Zealand grass grub larvae. Although the available biopesticide is effective, its use is limited to areas where sub-surface application is feasible, and is also impacted by soil conditions such as moisture levels and osmolarity. The aim of this study was to elucidate the responses of S. entomophila to osmotic and desiccation stresses in relation to challenges encountered during production, storage and soil application, with the goal of developing a more robust and versatile biocontrol agent. RpoS is a key factor in the stress response of many enteric bacteria. In order to dissociate the effect of RpoS from subsequent cellular stress studies, an rpoS mutant was constructed by site-directed mutagenesis. Assessment of the rpoS mutant showed that RpoS was not implicated in NaC1 or desiccation tolerance of S. entomophila. The rpoS mutant was instead found to have enhanced salt tolerance and could be distinguished from the wild-type by the ability to ferment arabinose, a phenotype that was confirmed through complementation. Complete abolition of the amber disease process was observed using an rpoS strain also missing the Sep virulence genes, suggesting that RpoS is a regulator of the S. entomophila anti-feeding prophage (Afp). These findings indicate a subtle interplay between NaC1 tolerance, virulence and RpoS-mediated regulation of amber disease in S. entomophila. A transposon mutagenesis screen was carried out to identify genes associated with NaC1 tolerance in S. entomophila. Fourteen mutants displaying NaC1 sensitivity were identified, two of which had mutations in genes with potential implications for the formulation of the bacterium as a biocontrol agent. The gene leuO that encodes a LysR-family transcriptional regulator was found to be essential for S. entomophila NaC1 tolerance. The toxicity of increased cellular LeuO from an over-expression vector led to the investigation of the effects of leuO mutation on the proteome. Multiple protein changes observed by two-dimensional gel analysis suggested that LeuO may be a global regulator in S. entomophila, as has been hypothesised for Salmonella species. A second NaC1-sensitive mutant contained an insertion in afp15, the product of which is thought to be involved in assembly of the Afp. As well as being sensitive to NaC1, the afp15 mutant was unable to induce the anti-feeding component of amber disease, again highlighting the link between stress tolerance and virulence in S. entomophila. This study also determined that pre-exposure to NaC1 in conjunction with the provision of exogenous glycine betaine significantly enhanced the survival of S. entomophila either in a desiccated state or after application to soil, regardless of the soil moisture content. The implication of this finding on the future formulation of S. entomophila led to investigation of the underlying genetic mechanisms involved in glycine betaine synthesis and NaC1 tolerance. The genes involved in glycine betaine biosynthesis from choline were identified through genomic comparison, degenerate PCR and primer walking. A 6.5 kb region was sequenced and found to contain four genes with homology and similar chromosomal arrangement to the E. coli bet genes (betTIBA). The S. entomophila betIBA genes comprised an operon, flanked by the divergently-transcribed betT gene whose product is responsible for choline transport. To ascertain the relative transcription levels of components of the bet operon, quantitative RT-PCR was performed. Results of qRT-PCR showed that choline in conjunction with NaC1 induced the greatest levels of bet gene transcription, and that levels of the betA transcript were significantly lower than those of the other bet genes. Examination of the betA 5� non-coding region identified a previously undetected hairpin region, possibly accounting for the observed decrease in betA transcript levels. The findings of this study have significantly advanced our understanding of how S. entomophiia responds to stress, and will contribute to the development of formulation strategies for the production of a robust product capable of application to pasture by a range of teclmiques. In addition, there is significant potential to utilise these findings in the development of other bacterial inocula for a range of biotechnological applications.

Despite high prevalence rates of insomnia among the elderly, very few treatment options adapted to the characteristics and needs of this population group exist. This study aims to investigate the efficacy of a thermal biofeedback based technique in treating sleep onset insomnia in an elderly sample. Eight healthy elderly good sleepers and eight healthy elderly sleep onset insomniacs participated in the study. The effect of the thermal biofeedback on participants' forehead temperature, clavicular temperature, right hand temperature, left hand temperature, stomach temperature, thigh temperature, right foot temperature, core body temperature, and sleep latency was assessed. Furthermore, the impact of the thermal biofeedback technique on participants' subjective ratings of biofeedback proficiency and sleepiness was investigated. The thermal biofeedback protocol failed to generate adequate and consistent changes in participants' body temperature, indicating that it is of limited practical used as a treatment of sleep onset insomnia in its present form. Several interesting trends observed during the current study are explored and areas for further research identified. / Thesis (MPsy(Clinical))--University of South Australia, 2006.

Bibliography: leaves 233-263. / xxix, 263, 14 leaves. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Crop Protection, 1999

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

Bibliography: leaves 207-220. / 220 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Pseudomonas corrigata strain 2140 (Pc2140), isolated from wheat field soil in Australia, antagonises the take-all fungus, Gaeumannomyces graminis var. tritici (Ggt) in vitro and significantly reduces take-all symptoms on wheat in pot trials. This study investigates the mechanisms by which the biocontrol agent reduces the disease symptoms. Biochemical analysis of metabolites of P. corrugata 2140 reveal a number of compounds potentially antagonistic to Ggt and which may play a role in disease control. These include water-soluble antibiotics, siderophores, proteases, peptides and volatiles including hydrogen cyanide. / Thesis (Ph.D.)--University of Adelaide, Dept. of Crop Protection, 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 175-191. / xx, 191 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Trissolcus basalis (Wollaston) is a solitary endoparasitoid of the eggs of many pentatomid bugs. It is a quasi-gregarious scelenoid and aggressively defends host patches. In the Adelaide (S. Aust.) region its most abundant host is the native horehound bug, Agonoscelis rutila (Fabricius). This study of patch defence draws together important areas of research in parasitoid behavioural ecology, including the theories of adaptive superparasitism, sex ratio decisions, foraging behaviour and contest resolution. / Thesis (Ph.D.)--University of Adelaide, Dept. of Crop Protection, 1997

Bibliography: leaves 233-263. / xxix, 263, 14 leaves. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Crop Protection, 1999