Research Infrastructure: Sustaining Medicago truncatula mutant resources for legume biology research

Legumes play a crucial role in sustainable agriculture due to their capability of symbiotic association with soil bacteria to fix nitrogen gas for plant growth. Medicago truncatula is a model legume species to study biological processes that are unique to legumes because most legumes have complex genomes that make genetic manipulations infeasible. Mutants in M. truncatula are thus irreplaceable resources in understanding gene functions in legumes.

From 2004 to 2013, the PI and the Co-PI generated legume mutant collection with ~21,000 insertional mutant lines in M. truncatula. In addition, a large-scale fast neutron deletion mutant collection was also generated in M. truncatula. These mutant resources are hosted at Oklahoma State University and are accessible to worldwide users through a web-based database.

From 2007 to 2022, more than 15,500 mutant lines have been distributed to 220 research groups in 29 countries. Students on the project will receive infrastructure management training to handle seed requests, seed retrieval, seed cleaning, documentation, invoicing, shipping, and PCR reverse screening that includes primer designing, PCR amplification, gel electrophoresis and sequencing.

From 2004 to 2013, ~21,000 Medicago truncatula retrotransposon Tnt1 insertion lines (Tnt1) were developed at the Noble Research Institute and out of these lines, about 400,000 flanking sequence tags (FSTs) were recovered by using next generation sequencing. In addition, a large-scale fast neutron bombardment (FNB) deletion mutant collection was also generated in M. truncatula.

In 2021, these resources were transferred to the Institute for Agricultural Biosciences, Oklahoma State University. The mutant collections are accessible to users worldwide through a web-based database, which contains phenotype descriptions and photos of individual lines, BLAST-searchable FST sequences and a JBrowser genome viewer. Since the first seed distribution in 2007, a total of more than 15,100 Tnt1 lines and 400 FNB lines have been distributed to 220 research groups in 29 countries.

Continued distribution and characterization of mutant lines is expected to support research into basic biological mechanisms and applications related to the bioeconomy or biotechnology.

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.