Many higher plants use self-incompatibil ity (SI) mechanism to prevent inbreeding and thus encouraging outcrossing. Upon a self-challenge in Papaver rhoeas, a Ca2+-dependent-signal ling-cascade is initiated resulting in the destruction ofthe self-pollen by Programmed Cell Death. Upstream ofPCD, several Sl-specific events are triggered in incompatible pollen, including phosphorylation of soluble inorganic pyrophosphatases (sPPases); alterations to actin; increases in Reactive Oxygen Species (ROS) and Nitric Oxide (NO). In Papaver pollen, sPPases play an important role, as they provide the driving force for biosynthesis; data suggested that Ca2+ and phosphorylation inhibits the sPPases activities, contributing to pollen tube inhibition. Work presented in this thesis characterized Pr-p26.1 sPPases and analysis of phosphomimic mutants in the SI signalling. These studies provide good evidence that, together with Ca2+, phosphorylation, H20 2 and pH dramatically affect sPPase activity. As previous studies showed that increases in ROS and NO are triggered by Sl in incompatible pollen, to provide insights into SI-mediated events, this project investigated protein-targets in pollen modified by oxidation and Snitrosylations after Sl, including actin and actin-associated proteins. Using a mass spectrometry approach we identified several proteins that were modified by oxidation and S-nitrosylation. This has provided us with several potential new mechanisms involved in Sl.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:667817 |
| Date | January 2015 |
| Creators | Haque, Tamanna |
| Publisher | University of Birmingham |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://etheses.bham.ac.uk//id/eprint/6237/ |
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