Unravelling the control and coordination of mitochondrial function within plant cells in response to environmental change

[Truncated abstract] Mitochondria are specialised organelle structures, which are present in most eukaryote cells and are essential for life and energy in these organisms. Mitochondria are responsible for cellular energy production through the process of aerobic respiration, and support and maintain a plethora of essential biochemical reactions throughout the cell. Therefore, these organelles are crucial and dynamically involved in cellular stress responses, growth, and interactions with the external environment in order to maintain cell viability. Mitochondria rely on the expression of nuclear located genes that encode the majority of mitochondrial components necessary for efficient organelle function and hence, there are a number of internal cellular communication pathways between the nucleus and the mitochondria to effectively control mitochondrial function. In plant cells, this is complicated by the presence of additional organelle structures, which also contribute to cellular energy production, such as the chloroplast. Thus, signalling pathways must be able to integrate the control of mitochondrial function within the context of whole cell metabolism and with the functionality of other energy organelles. However, we know very little about the molecular mechanisms by which this occurs in plant cells. The aim of the research in this thesis was to address two major questions; 1) How is the expression of mitochondrial proteins controlled in plant cells? and, 2) How does this regulation fit into other communication pathways that have already been characterised in plant cells? The dynamic induction in expression for several mitochondrial components can be observed in transcriptional responses to biotic and abiotic stress signals.