Researchers pinpointed the identity of one such toxin used by a soil-dwelling bacterium that protects plants from disease, according to the report of McMaster University in Canada. The bacterium Pseudomonas protegens can kill soil-dwelling plant pathogens, including fungi and bacteria that attack the roots of important crops such as cotton.

Pseudomonas protegens releases diverse antimicrobial compounds into the soil, but John Whitney, one of researchers, was curious specifically about the compounds that it was injecting directly into other bacteria through the type VI secretion system, or T6SS.