Some fungi have been very helpful to humans, like the ascomycetous fungi that generate the antibiotic penicillin. Scientists have now identified a soil fungus called Mortierella alpina that produces bioactive molecules that could help shield plants from problematic worms. A new study reported in the Journal of the American Chemical Society has shown how these fungal compounds, which are called malpinins, disrupt nematode worms that prey on plants. This work could eventually help create more environmentally-friendly and sustainable pesticides.
Malpinins are natural detergents, and the researchers found that they accumulate in the digestive tract of small worms. The worms were not immediately killed when they were exposed to malpinins, but they stopped feeding. "This ultimately led to a slow but effective control of the worms," explained first study author Dr. Hannah Büttner of the Leibniz Institute for Natural Product Research and Infection Biology—Hans Knöll Institute (Leibniz-HKI).
The investigators suggested that an amino acid called dehydrobutyrin is essential to the action of malpinins. There is a double bond in the dehydrobutyrin compound that is highly reactive, and which may be interacting with molecules in the worm intestine that are essential to digestive function. When the investigators removed dehydrobutyrin from malpinins, they no longer had any effect on worms.
“This indicates that precisely this structure is essential for biological activity. Without it, the compound is ineffective,” noted study co-author Johannes Raßbach of Friedrich Schiller University Jena.
Fungi are a normal part of healthy soils. Learn more about how fungi can affect plants from the video above.
The Mortierella alpina fungus naturally grows in cool and temperate soils, and may improve sustainability efforts in agriculture. It already has some industrial applications, the researchers noted, such as in the production of baby food. Now they are planning to learn more about this fungus and the compounds it produces to see if they can be applied in agriculture.
Sources: Leibniz-HKI, Journal of the American Chemical Society