The United Nations estimates that almost 800 million people do not have enough to eat. One key factor in fighting famine is food security. A major related challenge is the filamentous fungus Fusarium, which destroys colossal quantities of cereal crops such as wheat and barley globally by reducing yields and making cereal crops poisonous through mycotoxins.
The situation is especially serious in low-income countries, which already face great problems because they cannot afford resistant crops or crop rotation. These countries therefore depend strongly on effective fungicides. An article by Danish researchers in Pesticide Biochemistry and Physiology thus provides both really bad, and really good news.
Using real-time microscopy imaging, the Danish researchers from Aalborg University examined how the fungicide JS399-19 affects Fusarium. When it was discovered, JS399-19 was hailed as a miracle product since it could reduce the quantity of Fusarium and thereby the level of mycotoxins in cereal crop stores by 80%. In addition, there was no immediate cross-resistance, so its use did not negate the use of other fungicides.
Unfortunately, the new research shows that everything is not quite as rosy. JS399-19 kills Fusarium by affecting one of its key proteins, type I myosin. However, the new research revealed that a single mutation in one of the protein’s amino acids can render Fusarium resistant to the fungicide. The researchers therefore indicated that care should be taken not to overuse the fungicide.
The good news is that the research has provided a completely new and unique molecular overview of where to look for the next weapon against Fusarium. The protein to which JS399-19 binds itself is so key and well retained in different types of Fusarium that the researchers think that computer models can be used to construct new fungicides that are even more effective than JS399-19.
“Real-time imaging of the growth-inhibitory effect of JS399-19 on Fusarium” has been published in Pesticide Biochemistry and Physiology. In 2015, the Novo Nordisk Foundation awarded a grant to Jens L. Sørensen for the project Direct Cloning and Expression of Large Natural Product Gene Clusters in Fungi.