NSF Postdoctoral Fellowship in Biology: Methods for Virus-based Plant Genome Editing

Meyer, Chandler Marie, Madison WI

Investigators

Abstract

This action funds an NSF Plant Genome Postdoctoral Research Fellowship in Biology for FY 2023. 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 Chandler Meyer is “Methods for Virus-based Plant Genome Editing” The host institution for the fellowship is the University of Minnesota and the sponsoring scientist is Dr. Daniel Voytas. Precision editing of plant genomes has the potential to accelerate crop improvement and advance functional genomics. Considerable progress has been made in this area, however, the most commonly used methods for gene editing in plants often require the use of tissue culture. The drawback of tissue culture is that it requires technical expertise, it is time intensive, and success is limited to a few genotypes. This project aims to develop a viral-based method of genome editing in plants that offers the potential to significantly reduce the need for tissue culture. If successful, the methods developed could be applied to crop species and greatly accelerate the ease of gene editing in crop plants, improving the ability of breeders to create new traits. The results from this work could also have a broad impact on plant biology by streamlining methods for generating mutants for gene function studies. Training objectives include outreach activities to promote community engagement in plant gene editing and plant science, mentoring undergraduate students, and dissemination of plant gene editing techniques by participation in the NSF-funded Plant Genetic Engineering Network (PlantGENE). The most commonly used methods to deliver gene editing reagents to plant cells are Agrobacterium-mediated transformation and biolistic bombardment. To recover a gene-editing plant, tissue culture techniques are needed to regenerate a plant from the edited somatic cells. This is challenging for a few reasons. First, it often requires months of training and development of technical expertise. Second, successful regeneration is often limited to a few genotypes. Lastly, the tissue culture process can result in somaclonal variation. The use of viruses for genome modification in plants offers the potential to ease the tissue culture and reagent delivery bottlenecks. The research objectives of this project are to (1) improve the cargo capacity of TRV-based vectors so that TRV can deliver CRISPR-Cas nucleases to meristematic cells, (2) test the use of miniature CRISPR-Cas nucleases to overcome TRV-based vector cargo capacity limitations, and (3) identify RNA sequences that increase cell-to-cell mobility of sgRNAs and nucleases to promote delivery to the germline. This research will generate knowledge of methods for genomic modification of plants that can be used by plant breeders and researchers to develop novel traits and study gene function. Data generated will be released to the community through submission to public repositories, project web pages, and publications as well as presentations at scientific conferences, seminars, and workshops. Germplasm will be available upon request. 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.