VATIS UPDATE Article

Researchers at Oregon State University (OSU), the United States, have discovered a bacterium common in insects found in a plant-parasitic roundworm, opening up the possibility of a new, environmentally friendly way of controlling the crop-damaging pest. The worm, ‘Pratylenchus penetrans’, is one of the ‘lesion nematodes’ – microscopic animals that deploy their mouths like syringes to extract nutrients from the roots of plants, damaging them in the process.

This particular nematode uses more than 150 species as hosts, including mint, raspberry, lily and potato. The newly discovered bacterium is a strain in the genus Wolbachia, one of the world’s most widespread endosymbionts - organisms that live within other organisms. Wolbachia is present in roughly 60 percent of the globe’s arthropods, among them insects, spiders and crustaceans, and also lives in nematodes that cause illness in humans.

Depending on the host species, Wolbachia can be an obligate mutualist – the bacteria and the host needs each other for survival – or a reproductive parasite that manipulates the host’s reproductive outcomes in ways that harm the host and benefit the bacteria. In the case of the crop-pest nematode, Pratylenchus penetrans, the bacteria-host relationship appears to not be one of obligate mutualism – many examples of non-infected worms have been found, meaning the worm doesn’t rely on Wolbachia to survive.