Scientists have discovered a way to stop the spread of a fungus that destroys up to 30% of the world's rice crop each year.
An international team led by the University of Exeter showed that a chemical inhibition of a single protein in a fungus called rice blast prevents it from spreading inside a rice leaf - instead leaving it trapped within a single plant cell.
The researchers say their finding is a breakthrough in terms of understanding the disease, but is not yet a cure that can be applied outside the laboratory.
Their work showed how the fungus can manipulate and squeeze through natural channels, called plasmodesmata, that exists between plant cells.
Professor Nick Talbot, of the University of Exeter, said: "This is an exciting breakthrough because we have discovered how the fungus is able to move stealthily between rice cells, evading recognition by the plant immune system.
"It is clearly able to suppress immune responses at pit fields (groups of plasmodesmata), and also regulate its own severe constriction to squeeze itself through such a narrow space.
"And all this is achieved by a single regulatory protein. It's a remarkable feat."
Rice blast destroys enough of the crop each year to feed 60 million people, the researchers say.
The researchers used chemical genetics to mutate a signalling protein to make it susceptible to a specific drug.
This protein, PMK1, is responsible for suppressing the rice's immunity and allowing the fungus to squeeze through pit fields. By inhibiting it, the researchers were able to trap the fungus within a cell.
They found that just one enzyme, called a MAP kinase, was responsible for regulating the invasive growth of rice blast.
The research was published in the journal Science.