Abstract

Plants are highly sensitive to ambient temperature and can modify their growth and development in response to changes as small as 1˚C. In the model plant Arabidopsis thaliana, hundreds of genes undergo transcriptional reprogramming within minutes of exposure to heat, a process regulated in part by heat-shock factors. The Wigge laboratory has demonstrated that transcriptional regulation of temperature responses involves changes in occupancy of the histone variant H2A .Z, though the means by which this chromatin alteration occurs is unknown. Despite considerable efforts to identify temperature sensors in plants, the primary mechanism of temperature perception remains to be discovered. In parallel to an on-going forward genetic screen being conducted by the Wigge laboratory, I am using a chemical genomics approach to identify proteins required for temperature signalling in A. thaliana. In order to gain a better understanding of the role of H2A .Z in the heat-shock response, I am investigating post-translational modifications of H2A .Z and the interplay between H2A .Z-containing nucleosomes and stress-associated transcription factors in Saccharomyces cerevisiae. As well as identifying key components of temperature signalling pathways in plants, this project could potentially identify chemicals with useful agricultural applications, such as thermal protection of plant reproduction.