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Receptor-like protein kinases (RLKs) containing an extracellular leucine-rich-repeat (eLRR) domain, a transmembrane domain, and a cytoplasmic kinase domain play important roles in plant disease resistance. Simple eLRR domain proteins structurally resembling the extracellular portion of the RLKs may also participate in signaling transduction and plant defense response. Yet the molecular mechanisms and subcellular localization in regulating plant disease resistance of these simple eLRR domain proteins are still largely unclear. We provided the first experimental evidence to demonstrate the endosomal localization and trafficking of a novel simple eLRR domain protein (OsLRR1) in the endosomal pathway, using both confocal and electron microscopy. Yeast 2-hybrid and in vitro pull-down assays show that OsLRR1 interacts with the rice hypersensitive induced response protein 1 (OsHIR1) which is localized on plasma membrane. The interaction between LRR1 and HIR1 homologs was shown to be highly conserved among different plant species, suggesting a close functional relationship between the two proteins. The function of OsLRR1 in plant defense response was examined by gain-of-function tests using transgenic Arabidopsis thaliana. The protective effects of OsLRR1 against bacterial pathogen infection were shown by the alleviating of disease symptoms, lowering of pathogen titers, and higher expression of defense marker genes. / Zhou, Liang. / Adviser: Hon Ming Lam. / Source: Dissertation Abstracts International, Volume: 73-01, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 90-107). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

by Zeng Naiyan. / "December 2004." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (p. 185-213) / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.

Typescript. / Digitized by Kansas Correctional Industries

Field pea (Pisum sativum L.) is highly susceptible to ascochyta blight, primarily caused by the pathogen Mycosphaerella pinodes (Berk. & Blox.) Vestergr. Grasspea (Lathyrus sativus L.) has been reported to possess a moderate level of resistance to ascochyta blight caused by M. pinodes. The work reported in this thesis aimed to develop the various techniques that would be required to transfer ascochyta blight resistance from grasspea into field pea via somatic hybridisation. This thesis also assesses the feasibility of achieving this goal. Field pea shoot cultures were established on hormone-free MS medium, and a protoplast isolation protocol developed for both species. Grasspea shoot cultures were established on both RL and SSB8 medium. Friable grasspea callus was achieved on media supplemented with 2,4-D in the range 4.523 µM, whereas kinetin tested at any concentration did not appear to influence callus growth. A suspension culture of grasspea was developed for the first time, in B5 medium supplemented with 4.5 µM 2,4-D and 0.5 µM kinetin. Grasspea protoplasts were isolated from both in vitro seedlings and suspension cultures. Protocols for hybrid shoot culture on KM8p medium were developed via organogenesis and somatic embryogenesis.

"August 2004" / Bibliography: leaves 146-169. / vi, 169 leaves : ill, (some col.), photos (col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, School of Agriculture and Wine, Discipline of Plant and Pest Science, 2004

Take - all disease ( caused by Gaeumannomyces graminis var tritici, Ggt ) can be suppressed by soil microorganisms after continuous monoculture of wheat ( take - all decline, TAD ). Fluorescent pseudomonads have been implicated in this suppression. Two strategies for controlling take - ail are the in situ development of disease suppressive soil, and / or the application of a biocontrol agent. However, TAD takes up to 10 years to develop after initially high levels of disease, and the performance of bacterial biocontrol agents has been inconsistent. It is not known what environmental factors select for disease antagonists. In this work the role of diseased root lesions in directing the evolution of a native pseudomonad community, and a model disease antagonist, Pseudomonas corrugate strain 2140 ( Pc2140 ) for increased disease suppression was investigated. This work shows that root lesions are a distinct niche, supporting increased populations of total aerobic bacteria ( TAB ), pseudomonads and Pc2140 ( compared to non - lesioned sections of diseased roots and healthy roots ). Lesions selected for fluorescent pseudomonads and pseudomonads which increase take - all severity. In. contrast, lesions selected for non - pseudomonads which decrease take - all, and healthy roots selected for non - fluorescent pseudomonads which decrease take - all. It was concluded that non - fluorescent pseudomonads and non - pseudomonads were important in reducing take - all, but not fluorescent pseudomonads. Pc2140 produced multiple variant phenotypes in vitro and on wheat roots which were altered in ( 1 ) their ability to inhibit pathogens in vitro and control take - all, and ( 2 ) GC - FAME and BIOLOG profiles to the extent that some variants were identified as different species. Different sets of phenotypes were produced in vitro and on roots. After 108 weeks culture of Pc2140 on root lesions and healthy wheat roots, variant colony types were generally slightly decreased in ability to reduce take - all, and reisolates with the wild type colony morphology were generally slightly increased in ability to reduce take - all compared to the ancestral Pc2140. This is the first report on the diversification of a pseudomonad biocontrol agent on roots, and has implications for the taxonomic identification and grouping of isolates based on phenotypic characteristics. / Thesis (Ph.D.)--Department of Crop Protection, 1998.

Field pea (Pisum sativum L.) is highly susceptible to ascochyta blight, primarily caused by the pathogen Mycosphaerella pinodes (Berk. & Blox.) Vestergr. Grasspea (Lathyrus sativus L.) has been reported to possess a moderate level of resistance to ascochyta blight caused by M. pinodes. The work reported in this thesis aimed to develop the various techniques that would be required to transfer ascochyta blight resistance from grasspea into field pea via somatic hybridisation. This thesis also assesses the feasibility of achieving this goal. Field pea shoot cultures were established on hormone-free MS medium, and a protoplast isolation protocol developed for both species. Grasspea shoot cultures were established on both RL and SSB8 medium. Friable grasspea callus was achieved on media supplemented with 2,4-D in the range 4.523 µM, whereas kinetin tested at any concentration did not appear to influence callus growth. A suspension culture of grasspea was developed for the first time, in B5 medium supplemented with 4.5 µM 2,4-D and 0.5 µM kinetin. Grasspea protoplasts were isolated from both in vitro seedlings and suspension cultures. Protocols for hybrid shoot culture on KM8p medium were developed via organogenesis and somatic embryogenesis.

Bibliography: leaves 137-163. his is a comprehensive study of induced homoeologous recombination along most of the complete genetic length of two homoeologous chromosomes in the Triticeae (7A of common wheat and 7Ai of Agropyron intermedium), using co-dominant DNA markers. Chromosome 7Ai was chosen as a model alien chromosome because is has been reported to carry agronomically important genes conferring resistance to stem rust and barley yellow dwarf virus on its short and long arms, respectively.

Includes bibliographical references (l5 leaves) The aim of the work presented in this thesis was to develop molecular genetic markers for YD2 (the gene in barley which provides protection against barley yellow dwarf luteovirus) which could be used for the marker assisted selection of the gene in breeding programs and enable the gene to be cloned via a map-based approach.