Worm pheromones protect major crops

Protecting crops from pests and pathogens without using toxic pesticides has been a longtime goal of farmers. Researchers at Boyce Thompson Institute have found that compounds from an unlikely source – microscopic soil roundworms – could achieve this aim.

These compounds helped protect major crops from various pathogens, and thus have potential to save billions of dollars and increase agricultural sustainability around the world.

Led by BTI Senior Research Associate Murli Manohar, a team around Professors Daniel Klessig and Frank Schroeder investigated the effects of a roundworm metabolite called ascr#18 on plant health. Ascr#18 is a member of the ascaroside family of pheromones, which are produced by many soil-dwelling species of roundworms for chemical communication.

The researchers treated soybean (Glycine max), rice (Oryza sativa), wheat (Triticum aestivum) and maize (Zea mays) plants with small amounts of ascr#18, and then infected the plants with a virus, bacteria, fungus or oocmycete. When examined several days later, the ascr#18-treated plants were significantly more resistant to the pathogens compared with untreated plants.

"Plant roots are constantly exposed to roundworms in the soil, so it makes sense that plants have evolved to sense the pest and prime their immune systems in anticipation of being attacked," says Schroeder.