Graduate Student Washington University in St. Louis and Donald Danforth Plant Science Center SAINT LOUIS, Missouri
Body of Abstract: Gene duplication is an issue many plant scientists face when studying their genes of interest, as compensation can obscure mutant phenotyping efforts. However, when an early gene duplication is widely conserved, it is possible that the gene copies have functionally diversified. Recent advances in molecular crop breeding rely not on gene discovery but on fine-tuning of gene regulation and important biological processes. The molecular mechanisms that differentiate specialized gene copies can become tools for this type of crop improvement. Additionally, the specialized genes themselves may contribute to breeding efforts for important traits.
Argonaute (AGO) proteins play an important role in RNA-mediated gene silencing by loading small RNAs, 21- to 24-nucleotide molecules of RNA, and altering gene expression. Arabidopsis AGO1 plays a role in plant growth and responses to biotic and abiotic stress. Unlike Arabidopsis, which only has one AGO1 copy, rice, a crop that feeds millions globally, has four copies, potentially splitting the important roles of AtAGO1. The presence of multiple AGO1 copies, which is conserved across grasses such as maize and barley, can partially be explained by their subcellular localization. Rice AGO1a and AGO1b contain predicted nuclear localization signals in their N-coil domain while AGO1c and AGO1d do not, meaning that even if all four rice AGO1 proteins are present in the same tissue or the same cell, they may perform different functions due to their subcellular localization. In this study, I will confirm the predicted signals using transient expression in Nicotiana benthamiana.