Research
The soybean cyst nematode (SCN), a microscopic roundworm, is the most important pathogen of soybean and a billion-dollar problem in US agriculture. Currently, management relies almost exclusively on the use of SCN resistant soybean cultivars. Unfortunately, this approach has become less effective over time as nematodes have adapted to the resistant soybean genotype known as plant introduction (PI) 88788, which is present in more than 95% of commercially available resistant cultivars of soybean. Thus, there is an urgent agricultural need for new approaches to manage SCN infection, including new sources of SCN resistance.
Our current studies are based on the results of our collaborator, Dr. Melissa Mitchum (University of Georgia), who showed that the soybean cultivar known as “Forrest”, which derives resistance from PI 548402 (or Peking), is resistant to SCN infection because of two point mutations in the enzyme serine hydroxymethyltransferase (SHMT). SHMT is a central enzyme of folate metabolism and nucleotide biosynthesis and is found in all kingdoms of life. We are conducting basic, biophysical research on soybean SHMT to complement plant-based studies in the Mitchum laboratory. Our initial studies results showed that impaired folate binding of SHMT8 from cv. Forrest underlies SCN resistance in soybean. We are currently investigating other amino acid polymorphisms of SHMT8 as well as other enzyme isoforms in soybean.