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dc.contributor.authorAnderson, Ryan Gabrielen_US
dc.date.accessioned2017-04-06T15:43:45Z
dc.date.available2017-04-06T15:43:45Z
dc.date.issued2011-09-09en_US
dc.identifier.otheretd-09142011-144211en_US
dc.identifier.urihttp://hdl.handle.net/10919/77204
dc.description.abstractDiverse pathogens secrete effector proteins into plant cells to manipulate host cellular processes. The genome of Hyaloperonospora arabidopsidis (Hpa), the causative agent of downy mildew of Arabidopsis, contains at least 134 candidate RXLR effector genes. These genes contain an RXLR motif required for effector entry into host cells. Only a small subset of these candidate effectors is conserved in related oomycetes. Here, we describe a comparative functional characterization of the Hpa RXLR effector HaRxL96 and a homologous gene, PsAvh163, from the soybean pathogen Phytophthora sojae. HaRxL96 and PsAvh163 are induced during early stages of infection and carry a functional RXLR motif that is sufficient for protein uptake into plant cells. Both effectors can suppress or activate immune responses in soybean, Nicotiana, and Arabidopsis. Several SA-responsive defense genes are suppressed in Arabidopsis Col:HaRxL96 and Col:PsAvh163 during an incompatible interaction with Hpa Emoy2. Both effectors are localized to the nucleus and cytoplasm of plant cells. Nuclear localization of both effectors is required for proper virulence functions, including suppression of basal resistance and RPP4-mediated immunity to virulent and avirulent Hpa, respectively. In addition, both effectors interact with plant U-box (PUB) proteins that are conserved between diverse plant species. The targeted PUB proteins are negative regulators of plant immunity in Arabidopsis. These experiments demonstrate that evolutionarily-conserved effectors from different oomycete species can suppress immunity in plant species that are divergent from the source pathogen's primary host.en_US
dc.language.isoen_USen_US
dc.publisherVirginia Techen_US
dc.rightsI hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to Virginia Tech or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report.en_US
dc.subjectOomyceteen_US
dc.subjecteffectoren_US
dc.subjectRXLRen_US
dc.subjectplant immunityen_US
dc.subjectHyaloperonospora arabidopsidisen_US
dc.titleIdentification and functional characterization of RXLR effector proteins that are conserved between downy mildew pathogens and Phytophthora speciesen_US
dc.typeDissertationen_US
dc.contributor.departmentPlant Pathology, Physiology, and Weed Scienceen_US
dc.description.degreePh. D.en_US
thesis.degree.namePh. D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen_US
dc.contributor.committeechairMcDowell, John M.en_US
dc.contributor.committeememberWestwood, James H.en_US
dc.contributor.committeememberTyler, Brett M.en_US
dc.contributor.committeememberLawrence, Christopher B.en_US
dc.contributor.committeememberWinkel, Brenda S. J.en_US
dc.type.dcmitypeTexten_US
dc.identifier.sourceurlhttp://theses.lib.vt.edu/theses/available/etd-09142011-144211/en_US
dc.date.sdate2011-09-14en_US
dc.date.rdate2016-09-27
dc.date.adate2011-10-13en_US


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