RUI: Genetic approaches to uncover mechanisms governing seasonal reproductive development in Physcomitrium patens

Seasonal information, including temperature and daylength, is used by many plant and animal species to coordinate their reproduction with the environment, so that their offspring are produced at an appropriate time of year. While many flowering plants use a very similar genetic process to sense and respond to seasonal cues, we have found that this same genetic process is not used in the distantly related moss Physcomitrium patens. Our goal is to determine how mosses sense and respond to seasonal cues. This information will inform us about how genetic regulation can evolve in distinct organismal lineages, and may provide new tools and approaches for engineering and altering reproduction in both flowering and non-flowering plants. Undergraduate research students will gain valuable expertise in research through involvement in all aspects of the project. The project will also provide a postdoctoral scientist with training and mentorship in both teaching and research. Finally, aspects of the project will be incorporated into genetics and genomics courses taught by the principal investigator. We seek to understand the molecular mechanisms governing seasonal reproduction in the moss Physcomitrium patens. Our previous work suggests that, while upstream light sensory pathways may be functionally conserved across land plants, a distinct and novel downstream pathway regulates reproductive development in response to seasonal cues in P. patens, and perhaps in other bryophytes. Using a combination of forward and reverse genetics, coupled with genomic and transcriptomic approaches, we propose to isolate key genes involved in this process and build a molecular framework for this novel downstream pathway. Specifically, we will use an unbiased mutagenesis screen to identify necessary components of this seasonal regulatory and evaluate their spatial and temporal regulation. In addition, we will use CRISPR mutagenesis to test the hypothesis that one or more photoperiod-dependent genes serve as inducers of reproductive development. Finally, we will use quantitative trait genetics to discover genes that underlie natural variation in reproductive timing observed across P. patens strains from different geographic regions. The project will provide significant research training and professional development for undergraduate students including presentation at regional and national conferences, and will provide an outstanding training opportunity for a postdoctoral scientist interested in undergraduate education. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.