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Abstract: Promoters are regions of DNA located directly upstream of gene coding regions and are the primary regulators of gene transcription. They are comprised of promoter elements, which are sequences that facilitate binding of RNA polymerase in conjunction with transcription factors, leading to transcription of downstream coding regions. This transcription can be regulated according to developmental stage, tissue type, or induction by a range of stimuli. Although constitutive promoters are studied and used most often, the discovery of new promoters and novel promoter elements will increase our understanding of gene expression and add to the available toolbox of promoters for production of transgenics. For this research, four RuBisCO small subunit soybean promoters (GmRbcs) were selected based on the sequence homology in their coding regions. RNAseq data revealed high expression of Rbcs1-3 in young leaf tissues, while Rbcs4 was expressed only in the root and nodule. In addition, GmRbcs1 and 3, along with other Rbcs genes, have been previously shown to be light regulated. The objectives of this project are to (1) isolate promoter regions and evaluate promoter activity using transient expression analysis in lima bean cotyledons and stable expression analysis in soybean hairy roots, (2) determine if any or all GmRbcs promoters are light inducible, and (3) identify elements responsible for light-inducibility using promoter truncation analysis and synthetic promoter design. Further characterization of these promoters will be useful in developing more targeted and efficient transgene regulation, as well as contribute to our understanding of transcriptional regulation.