"The project will exploit recent work in Arabidopsis (in the Dean laboratory) linking RNA metabolism and chromatin silencing (Liu et al 2009). The Dean group is focused on RNA-mediated chromatin regulation of an important repressor of flowering called FLOWERING LOCUS C (FLC). The concepts that have emerged from this study have wide relevance in many organisms. Conserved RNA 3’ processing factors function with an RNA-binding protein to target polyadenylation to a specific site in the FLC antisense transcript. This 3’ processing event triggers histone demethylation and transcriptional silencing of the locus. Their unpublished work shows that a conserved splicing factor, specifically PRP8, a core component of the spliceosome, also functions in this mechanism. The overall aim of the proposal is to reveal the molecular mechanism of involvement of splicing factor PRP8 on anti-sense RNA dependent regulation of transcription of FLC in Arabidopsis and to test generality of that mechanism on other anti-sense regulated genes.The specific objectives of the proposal include:1.Fully characterizing the FLC antisense transcript changes in the splicing factor mutant (prp8) mutant.2.Analysing the contributions of RNA degradation pathways in the accumulation of FLC antisense transcripts in wild type and in prp8 mutant backgrounds.3.Analysing the interactions between splicing and 3’ processing of the antisense transcripts.4.Generating and analysing directed mutations in PRP8 to explore whether the prp8 allele generated in the forward mutant screen is hypomorphic or has lost a specific function but is still wild-type for generic splicing functions.5.Analysing the components of the RNP complex that are assembled on the antisense transcript.A better understanding of the flowering control of the agricultural crops is fully in line with goals of research in the FP7 first priority thematic areas, such as Food, Agriculture and Biotechnology and Environment including climate changes."