Poster: Late and Moved Abstracts

Abs # 1358: Global expression profiling of the response of chemically regulated genes in Arabidopsis

Presenter:	Haslam, Richard P., richard.haslam@bbsrc.ac.uk
Authors	Haslam, Richard P. (A)   Downie, Andrew L. (A)   Miyazaki, Saori  (B)   Bohnert, Hans J. (B)   John, Philip  (C)   Coleman, Julian O.D. (D)   Parry, Martin A.J. (A)
Affiliations:	(A): CPI, Rothamsted Research, UK (B): University of Illinois, USA (C): University of Reading, UK (D): University of Oxford Brookes, UK

Chemically inducible systems that activate or inactivate gene expression have many potential applications in determining gene function and in plant biotechnology. Chemicals that have been used to regulate transgene expression include antibiotics such as tetracycline, steroids like dexamethasone, in addition to copper, ethanol and herbicide safeners. The completion of the Arabidopsis thaliana sequencing program provides a unique resource when coupled to the post-genomic technology presently available in the form of full genome array chips. Characterisation of those genes responding to chemical treatment provides an insight into gene function with regard to detoxification and stress response, but also makes available an inventory of genes responsive to chemical treatment that might find application. This project is centered on folate-independent one-carbon biochemistry, particularly the detoxification routes of methanol and subsequently formaldehyde. Methanol and its metabolites arise from a number of sources, for example, pectin de-methylation and atmospheric pollution. The key enzymes in this pathway include: (1) formaldehyde dehydrogenase, (2) S-formylglutathione hydrolase and (3) formate dehydrogenase. Their genes have been identified and cloned in Arabidopsis and rice following environmental and chemical stimuli. In Arabidopsis , a further characterisation of the impact of methanol on global plant metabolism was done by profiling transcript expression of a methanol treatment over a period of 72 hours. Analysis to date has revealed significant up regulation of genes involved in detoxification and defence pathways. Alterations in expression ratios point to a number of putative transcription factors that seem to mediate methanol-responsiveness.