Characterisation of putative metal transport proteins in the nickel hyperaccumulator Senecio coronatus: investigating candidate genes for nickel tolerance and accumulation

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dc.contributor.advisorIngle, Robert Aen_ZA
dc.contributor.authorCowlin, Ross Martinen_ZA
dc.date.accessioned2018-02-07T09:09:30Z
dc.date.available2018-02-07T09:09:30Z
dc.date.issued2017en_ZA
dc.description.abstractThe accumulation of exceptionally high concentrations of heavy metals in plant tissues is an extreme phenotypic trait that has evolved independently in multiple plant taxa. The majority of research undertaken in this area has been performed on zinc/cadmium hyperaccumulators and comparatively little is known about the molecular mechanisms behind nickel accumulation. This is despite the fact that nickel hyperaccumulators constitute more than 75% of all known hyperaccumulator species. One such species is Senecio coronatus (Asteraceae), which is a useful model to study nickel hyperaccumulation - as both hyperaccumulator and non-accumulator populations have been identified on nickel-rich serpentine soils in South Africa. The nickel-transporting abilities of three proteins (ScMATE, ScVIT and ScCOP), previously shown to be constitutively over-expressed in shoot tissues of hyperaccumulating populations of S. coronatus, were investigated in order to determine if they play a role in nickel hyperaccumulation. The RNA-Seq derived nucleotide sequences of these genes were confirmed by reverse transcriptase PCR, and computational analysis suggested that the proteins encoded by these genes display identical topology to their homologues in Arabidopsis thaliana. Heterologous expression of these proteins in a metal-sensitive yeast strain was performed to determine whether they are capable of transporting nickel. Although a minor reduction in nickel sensitivity was observed in yeast expressing ScMATE, and a minor increase in ScCOP-expressing yeast, no marked changes in sensitivity to nickel were observed. C-terminal EYFP-tagged MATE and VIT fusion proteins were transiently expressed in live onion cells to determine the subcellular localization of these proteins in planta. Fluorescence microscopy indicated that MATE localises to the nucleus and VIT to the tonoplast or plasma membrane.en_ZA
dc.identifier.apacitationCowlin, R. M. (2017). <i>Characterisation of putative metal transport proteins in the nickel hyperaccumulator Senecio coronatus: investigating candidate genes for nickel tolerance and accumulation</i>. (Thesis). University of Cape Town ,Faculty of Science ,Department of Molecular and Cell Biology. Retrieved from http://hdl.handle.net/11427/27373en_ZA
dc.identifier.chicagocitationCowlin, Ross Martin. <i>"Characterisation of putative metal transport proteins in the nickel hyperaccumulator Senecio coronatus: investigating candidate genes for nickel tolerance and accumulation."</i> Thesis., University of Cape Town ,Faculty of Science ,Department of Molecular and Cell Biology, 2017. http://hdl.handle.net/11427/27373en_ZA
dc.identifier.citationCowlin, R. 2017. Characterisation of putative metal transport proteins in the nickel hyperaccumulator Senecio coronatus: investigating candidate genes for nickel tolerance and accumulation. University of Cape Town.en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Cowlin, Ross Martin AB - The accumulation of exceptionally high concentrations of heavy metals in plant tissues is an extreme phenotypic trait that has evolved independently in multiple plant taxa. The majority of research undertaken in this area has been performed on zinc/cadmium hyperaccumulators and comparatively little is known about the molecular mechanisms behind nickel accumulation. This is despite the fact that nickel hyperaccumulators constitute more than 75% of all known hyperaccumulator species. One such species is Senecio coronatus (Asteraceae), which is a useful model to study nickel hyperaccumulation - as both hyperaccumulator and non-accumulator populations have been identified on nickel-rich serpentine soils in South Africa. The nickel-transporting abilities of three proteins (ScMATE, ScVIT and ScCOP), previously shown to be constitutively over-expressed in shoot tissues of hyperaccumulating populations of S. coronatus, were investigated in order to determine if they play a role in nickel hyperaccumulation. The RNA-Seq derived nucleotide sequences of these genes were confirmed by reverse transcriptase PCR, and computational analysis suggested that the proteins encoded by these genes display identical topology to their homologues in Arabidopsis thaliana. Heterologous expression of these proteins in a metal-sensitive yeast strain was performed to determine whether they are capable of transporting nickel. Although a minor reduction in nickel sensitivity was observed in yeast expressing ScMATE, and a minor increase in ScCOP-expressing yeast, no marked changes in sensitivity to nickel were observed. C-terminal EYFP-tagged MATE and VIT fusion proteins were transiently expressed in live onion cells to determine the subcellular localization of these proteins in planta. Fluorescence microscopy indicated that MATE localises to the nucleus and VIT to the tonoplast or plasma membrane. DA - 2017 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 2017 T1 - Characterisation of putative metal transport proteins in the nickel hyperaccumulator Senecio coronatus: investigating candidate genes for nickel tolerance and accumulation TI - Characterisation of putative metal transport proteins in the nickel hyperaccumulator Senecio coronatus: investigating candidate genes for nickel tolerance and accumulation UR - http://hdl.handle.net/11427/27373 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/27373
dc.identifier.vancouvercitationCowlin RM. Characterisation of putative metal transport proteins in the nickel hyperaccumulator Senecio coronatus: investigating candidate genes for nickel tolerance and accumulation. [Thesis]. University of Cape Town ,Faculty of Science ,Department of Molecular and Cell Biology, 2017 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/27373en_ZA
dc.language.isoengen_ZA
dc.publisher.departmentDepartment of Molecular and Cell Biologyen_ZA
dc.publisher.facultyFaculty of Scienceen_ZA
dc.publisher.institutionUniversity of Cape Town
dc.subject.otherMolecular and Cell Biologyen_ZA
dc.titleCharacterisation of putative metal transport proteins in the nickel hyperaccumulator Senecio coronatus: investigating candidate genes for nickel tolerance and accumulationen_ZA
dc.typeMaster Thesis
dc.type.qualificationlevelMasters
dc.type.qualificationnameMScen_ZA
uct.type.filetypeText
uct.type.filetypeImage
uct.type.publicationResearchen_ZA
uct.type.resourceThesisen_ZA
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