Understanding chloroplast/nuclear signaling and response pathways which determine photosynthetic capacity


To gain new insights into chloroplast/nuclear signaling pathways using in mutants where normal protein expression is perturbed by RNAi down regulation.


The regulation of chloroplast development and function requires a complex set of metabolic and regulatory interactions between the cytosol, the chloroplast and the nucleus within the leaf cell. There is an emerging understanding of signals generated within energy-transducing organelles, such as chloroplasts and mitochondria, and the nuclear genes that respond to them, a process known as retrograde signalling. However, much of this relates to the biogenesis of chloroplasts rather than their acclimation and optimization of function within the developing photosynthetic leaf cell. Investigating aspects of the regulatory and communication networks has involved the use of specific loss of function mutants as well as the application of photosynthetic inhibitors. However, the potential exists to learn about this process through studying RNAi mutants which have a graded loss of function of specific photosynthetic genes associated wit both thylakoid electron transport reactions and the Calvin CO2 fixation cycle.


Analyze gene regulation in a range of Arabidopsis RNAi mutants with down regulation of a range of specific photosynthetic genes involved in the Calvin cycle and the light reactions. This project aims to use these mutants to understand how gene expression and chloroplast/nuclear signaling is altered under situations where the ability to adjust the level of key photosynthetic gene transcripts and proteins has been specifically altered. Transcriptomics, proteomics, metabolomics and RT PCT analysis would be central tools. Physiological analysis of mutants plants would also be involved.