Co-PI: Matthew Hudson Proposal Number: IOS-0641639 Proposal Title: Role of FHY3 and FAR1 in transcriptional regulation of phytochrome A signaling in Arabidopsis
Plants use an array of photoreceptors to sense the ambient light environment and undergo adaptive growth and development. Phytochrome A (phyA) is the primary photoreceptor for mediating various far-red light induced responses in higher plants. It is widely accepted now that photo-activation of phyA initiates a signal transduction cascade that leads to regulated gene expression change and subsequent photomorphogenic development. FHY3 and FAR1, two homologous proteins that share significant amino acid similarities with the MuDRA class of transposases, define two essential positive regulators of phyA signaling in Arabidopsis. However, their molecular function and how they fit in the phyA signaling pathway have remained elusive. The central goal of this project is substantiate the hypothesis that FHY3 and FAR1 may define a novel class of transcriptional regulators, possibly domesticated from an ancient Mutator-like transposable element, that act in the nucleus to regulate phyA-responsive gene expression and photomorphogenic development under far-red light. The three specific aims are: 1. To characterize the transcriptional regulatory activity of FHY3 and FAR1 in plant cells; 2. To identify their direct target genes and functional characterization; and 3. To investigate their functional relationship with the photoreceptor phyA. Results from these studies will lead to a better understanding of FHY3 and FAR1 in regulating phyA-mediated gene expression and add critical information toward establishing a coherent phyA signaling pathway. The broader impacts expected from this work include training of different levels of scientists, ranging from undergraduate students, to graduate students and postdoc fellows. The PI will also participate in the training of local high school teachers and introduce the "Plants-In-Motion" movies, which were created by Professor Roger P. Hangarter at Indiana University, in local elementary school classes to teach school children about plant responses to light and other environmental signals.
