Project 1: Investigating the control of genetic crossover formation during meiosis in \(Arabidopsis\) \(thaliana\) and Project 2: Investigating the regulatory effects of \(N\)-acyl-homoserine lactones and hormone networks on spore germination in the model bryophyte \(Physcomitrella\) \(patens\)

Whitbread, Amy (2014). Project 1: Investigating the control of genetic crossover formation during meiosis in \(Arabidopsis\) \(thaliana\) and Project 2: Investigating the regulatory effects of \(N\)-acyl-homoserine lactones and hormone networks on spore germination in the model bryophyte \(Physcomitrella\) \(patens\). University of Birmingham. M.Res.

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Abstract

The following combined thesis consists of two research projects, carried out at the University of Birmingham. The first project analysed the control of meiotic crossovers in \(Arabidopsis\) \(thaliana\). Recombinant proteins were produced for two key meiotic proteins, AtSHOC1 and AtASY1, for use in antibody-based immunological studies. Additionally, protein interactions were analysed between AtPCH2 and a number of axis-associated proteins, via yeast two-hybrid analysis. AtPCH2 was found to self-interact and interact with the AtSPO11-accessory protein, PRD3, as seen with the rice homologues. AtPCH2 did not interact with AtASY1, even following disrupted ATP hydrolytic activity by mutagenesis, as was reported for the orthologues in budding yeast. The results of this study therefore suggest that either the function of AtPCH2 may differ in Arabidopsis to that observed in yeast, or that AtASY1 may require phosphorylation or additional proteins to interact. This project contributes to understanding the control of meiotic recombination in plants, and ultimately contributes to efforts to ensuring food security.
The second project involved investigating the control of spore germination in \(Physcomitrella\) \(patens\). The quorum-sensing signal molecules, \(N\)-acyl-homoserine lactones, were found to effect germination rates, with unsubstituted, long chain variants having more potent increasing effects overall. Additionally, increased germination rates in a DELLA-deficient mutant line, lacking the negative regulator of the gibberellin signalling pathway, were observed. This project thus provides novel data suggesting the presence of a DELLA-mediated GA signalling pathway in moss, controlling developmental processes, suggesting an earlier acquisition of this pathway during land plant evolution, than was previously believed.

Type of Work:

Thesis (Masters by Research > M.Res.)

Award Type:

Masters by Research > M.Res.

Supervisor(s):