Macrophomina phaseolina (Tassi) Goid., the causal agent of charcoal rot disease of soybean, is capable of causing disease in more than 500 other commercially important plants. This fungus produces several secondary metabolites in culture, including (-)-botryodiplodin, phaseolinone and mellein. Given that independent fungal isolates may differ in mycotoxin and secondary metabolite production, we examined a collection of 89 independent M. phaseolina isolates from soybean plants with charcoal rot disease using LC-MS/MS analysis of culture filtrates. In addition to (-)-botryodiplodin and mellein, four previously unreported metabolites were observed in >19% of cultures, including kojic acid (84.3% of cultures at 0.57–79.9 µg/L), moniliformin (61.8% of cultures at 0.011–12.9 µg/L), orsellinic acid (49.4% of cultures at 5.71–1960 µg/L) and cyclo[L-proline-L-tyrosine] (19.1% of cultures at 0.012–0.082 µg/L). In addition, nine previously unreported metabolites were observed at a substantially lower frequency (<5% of cultures), including cordycepin, emodin, endocrocin, citrinin, gliocladic acid, infectopyron, methylorsellinic acid, monocerin and N-benzoyl-L-phenylalanine. Further studies are needed to investigate the possible effects of these mycotoxins and metabolites on pathogenesis by M. phaseolina and on food and feed safety, if any of them contaminate the seeds of infected soybean plants.
Bibliographical noteFunding Information:
This research was funded by the Mississippi Soybean Promotion Board and supported by the Mississippi Agricultural and Forestry Experiment Station, the National Institute of Food and Agriculture and the US Department of Agriculture, Hatch project, under accession number 213130.
Funding: This research was funded by the Mississippi Soybean Promotion Board and supported by the Mississippi Agricultural and Forestry Experiment Station, the National Institute of Food and Agriculture and the US Department of Agriculture, Hatch project, under accession number 213130.
© 2020 by the authors. Licensee MDPI, Basel, Switzerland.
- Kojic acid
- Natural products
- Orsellinic acid
- Secondary metabolites
PubMed: MeSH publication types
- Journal Article