Oligomycin A controls soybean anthracnose in study

Researchers isolated oligomycin A from the fermented extract of Streptomyces paludis 13-3 and identified antifungal activity against Colletotrichum truncatum, the causal agent of soybean anthracnose. In detached seedlings, the compound achieved 85,85% control efficacy at a concentration of one microgram per milliliter, without causing phytotoxicity.

The study used bioassay-guided fractionation (doi 10.1002/ps.71177). The team characterized the substance by nuclear magnetic resonance spectroscopy and high-resolution mass spectrometry with electrospray ionization.

Oligomycin A showed an average effective concentration of 0,0173 micrograms per milliliter against mycelial growth. For conidia germination, the value reached 0,0811 micrograms per milliliter. The antifungal potency exceeded that of difenoconazole by approximately 58 times.

At a concentration of 0,1 micrograms per milliliter, the substance inhibited eight tested phytopathogens. Inhibition levels ranged from 61,69% to 83,39%.

Fluorescent staining and scanning electron microscopy analyses indicated intracellular accumulation of reactive oxygen species and structural damage in Colletotrichum truncatum.

According to the researchers, the results provide the first evidence of the action of oligomycin A against Colletotrichum truncatum. The natural compound may serve as a reference molecule for the development of new antifungal agents intended for the management of soybean anthracnose.