NSF NPGI Postdoctoral Fellowship in Biology FY 2016

Leiboff Samuel A, Albany CA

Investigators

Abstract

This action funds an NSF National Plant Genome Initiative Postdoctoral Research Fellowship in Biology for FY 2016. 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 Dr. Samuel Leiboff is "Exploring Gene Networks in Maize Tassel and Sorghum Panicle Development during Drought" The host institution for the fellowship is the USDA-ARS Plant Gene Expression Center and the sponsoring scientist is Dr. Sarah C. Hake. Increasing crop yield during drought is a critical challenge for U.S. corn production. The male flowering structure or tassel of the corn plant makes several branches, which produce the pollen necessary for fertilizing female flowers found in corn ears. During severe drought early in the growing season, energy is re-routed from the tassel to the ear and the number of tassel branches decreases, potentially leading to a shortage of pollen during the season. Sorghum's flowering structure, or panicle, is highly drought-resistant and sorghum has therefore been studied as an ideal crop for drier regions of the U.S. This project aims to understand genome-wide responses to drought in corn tassels and sorghum panicles, providing molecular information for breeding better plant performance during drought. Broader impacts include the formation of undergraduate outreach programs promoting STEM majors, research, and career opportunities to increase participation and retention of LGBT undergraduate students in STEM academic and professional fields. Students will be surveyed over time and long-term management of the programs will be transferred to campus advocacy groups, providing an outreach model for campuses nationwide. Training objectives include genomics, bioinformatics, biological modeling, and molecular genetics. Although previous studies have elucidated gene regulatory networks (GRNs) responsible for tassel branching in maize, little is known about how tassel GRNs respond to abiotic stresses, such as drought. Whereas several maize GRNs are conserved in other grasses, sorghum panicle GRNs have not been established. Using drought to manipulate tassel/panicle morphology, this project will explore GRN-wide drought response in maize and sorghum, including known mutants of tassel/panicle morphology. This research will use RNAseq to analyze inflorescence tissue from several different drought simulations. Leveraging existing GRN and genome resources in maize and sorghum, this project will generate and compare dynamic, drought responsive tassel/panicle GRNs. With these GRNs, morphological models linking RNA levels to tassel/panicle branching will be constructed. To test morphological-GRN models, this project will generate and analyze novel tassel/panicle mutants generated by CRISPR/Cas9 gene editing techniques. Research findings and analysis methodologies will be disseminated through conferences, publications, and submissions to data/code repositories (NCBI-SRA, NCBI-GEO, GitHub, MaizeGDB, and Grassius). Keywords: abiotic stress, co-expression networks, drought, inflorescence biology, maize genetics