NSF Postdoctoral Fellowship in Biology FY 2016

Taylor-Teeples Mallorie M, Seattle WA

Investigators

Abstract

This action funds an NSF National Plant Genome Initiative Postdoctoral Research Fellowship in Biology for FY 2015. The fellowship supports a research and training plan in a host laboratory for the Fellow who also presents a plan to broaden participation in biology. The title of the research and training plan for this fellowship to Mallorie Taylor-Teeples is "The Role of Protein Degradation in Plant Growth Patterning" The host institution for the fellowship is the University of Washington and the sponsoring scientist is Dr. Jennifer Nemhauser. Increasing crop yield is essential to meet the rising demand for food, feed and fuel. One major area for improvement is the manipulation of plant architecture. The patterning of flowers along the shoot (phyllotaxy) determines the positioning of grain or fruit along a stem. A key player in the process of phyllotaxy is the plant hormone auxin. Recent research in the Nemhauser Lab has found that phyllotactic patterning in the model plant Arabidopsis thaliana can be altered by changing one protein in the auxin response pathway. This project aims to test whether these findings can be applied to multiple plant species. If successful, this work will pilot a pipeline for rapid engineering of desirable agronomic traits into diverse crops with limited genomic infrastructure. Research findings will be disseminated through publications and presentations at scientific conferences. Public outreach will include workshops with high school and middle school students to facilitate understanding of basic biological concepts surrounding plant biology. Evolution has given rise to a staggering diversity of body plans. Effective methods for altering the patterning of organ emergence around the shoot are of agronomic interest, as phyllotactic patterning affects light harvesting capacity and determines the density of grain or fruit along a stem. Through the novel application of plant synthetic biology tools, the Nemhauser Lab has found that phyllotactic patterning can be altered by re-programming degradation rates of IAA28, an auxin repressor protein. Auxin-mediated degradation of repressive Aux/IAA substrate proteins via the E3-ubiquitin ligase pathway induces auxin-mediated transcriptional responses. BARREN INFLORESCENCE 4, a putative ortholog of IAA28 in Zea mays, also plays a role in phyllotaxy, suggesting that that the diversity in natural phyllotactic patterns across plant species can be explained in part by variation in auxin repressors. This project focuses on the readily tune-able parameter of auxin-induced degradation rate as a potential mechanism to precision engineer new body plans. These studies will be performed in parallel in three plants: Arabidopsis thaliana, Zea mays and Brassica rapa.