Characterization of the intraspecific variation within the nickel (Ni) hyperaccumulator species Senecio coronatus (Asteraceae): a preliminary analysis of genetic population structure and shoot proteome expression

 

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dc.contributor.advisor Ingle, Robert en_ZA
dc.contributor.advisor Bishop, Jacqueline en_ZA
dc.contributor.advisor Muasya, Muthama en_ZA
dc.contributor.author Wolf, Michael en_ZA
dc.date.accessioned 2014-11-05T03:46:47Z
dc.date.available 2014-11-05T03:46:47Z
dc.date.issued 2013 en_ZA
dc.identifier.citation Wolf, M. 2013. Characterization of the intraspecific variation within the nickel (Ni) hyperaccumulator species Senecio coronatus (Asteraceae): a preliminary analysis of genetic population structure and shoot proteome expression. University of Cape Town. en_ZA
dc.identifier.uri http://hdl.handle.net/11427/9109
dc.description Includes bibliographical references. en_ZA
dc.description.abstract Heavy metal (HM) accumulator plants possess the ability to actively hyperaccumulate and detoxify exceptionally high concentrations of metals in their aboveground tissues, without exhibiting any apparent signs of toxicity. Despite nickel (Ni) hyperaccumulator plants representing the largest percentage of known metal accumulator taxa (over 75%), the underlying genetic and molecular basis of Ni accumulation remains unclear. A prominent difficulty in understanding Ni hyperaccumulation has been the severe lack of intraspecific variation in the trait. Hence, the study of a single species exhibiting a significant degree of variation is highly desirable. as it avoids the use of inter-species comparative studies mostly utilized to date. The Ni hyperaccumulator Senecio coronatus (Asteraceae) has been reported to contain a significant degree of phenotypic plasticity with respect to the amount accumulated and subsequent cellular distribution of Ni. This apparent intraspecific variation means that S. coronatus may represent a useful system in which to study Ni hyperaccumulation. No population genetics study has been carried out to date on this species, and the evolutionary relationships between hyper and non- accumulator populations were unknown. Here, results are presented from a genetic analysis of 15 naturally occurring S. coronatus populations. Analysis of molecular variance (AMOVA) and phylogenetic analysis (based on non-coding nuclear and plastid markers) suggest that Ni accumulation may have evolved twice within S. coronatus, as hyperaccumulator plants from site Kaapsehoop, cluster with non-accumulating serpentine populations and demonstrate distinct genetic differentiation from other accumulator populations. Four populations were selected for a preliminary comparative shoot proteome analysis by means of two-dimensional SDS-polyacrylamide gel electrophoresis (2D SDS-PAGE) to identify proteins potentially involved in Ni hyperaccumulation. This analysis identified nine chloroplastic proteins involved in plant energy production and metabolism as overexpressed in hyperaccumulator plants from Agnus Mine and Kaapsehoop, compared to hypertolerant non-accumulator and non-serpentine plants from Galaxy Mine and Pullen Farm, respectively. However, no difference in photosynthetic efficiency, as determined by chlorophyll fluorescence measurements, was detected between these populations. en_ZA
dc.language.iso eng en_ZA
dc.title Characterization of the intraspecific variation within the nickel (Ni) hyperaccumulator species Senecio coronatus (Asteraceae): a preliminary analysis of genetic population structure and shoot proteome expression en_ZA
dc.type Thesis / Dissertation en_ZA
uct.type.publication Research en_ZA
uct.type.resource Thesis en_ZA
dc.publisher.institution University of Cape Town
dc.publisher.faculty Faculty of Science en_ZA
dc.publisher.department Department of Molecular and Cell Biology en_ZA
dc.type.qualificationlevel Masters en_ZA
dc.type.qualificationname MSc en_ZA
uct.type.filetype Text
uct.type.filetype Image


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