Nematodes, which are approximately one millimeter in length and parasitize plant roots, cause significant agricultural damage worldwide, and their control has become an urgent issue for stable crop production. When invaded by various pathogens, plants recognize characteristic molecules commonly present in them as markers and activate immune responses. While plant cell surfaces are equipped with receptors that detect such markers, how nematodes trigger plant immune responses was not well understood until now.
A research team led by Group Director Ken Shirasu at the RIKEN Center for Sustainable Resource Science discovered that a species of nematode that can be cultivated en masse in the laboratory triggers strong immune responses in Arabidopsis despite lacking the ability to parasitize plants. By purifying active substances from extracts of these nematodes, the team revealed that a peptide consisting of only 24 amino acids, which is part of an enzyme called "secreted trehalase," causes the immune response. Furthermore, they identified the receptor kinase that plants use to activate this immune response. They also found that this peptide is commonly present in diverse plant-parasitic nematodes, pests, and pathogenic fungi.
By elucidating the mechanism by which plants recognize nematodes at the molecular level, this research has significantly advanced our understanding of plant immunity. Finding defensive substances against such pathogens may enable the development of new types of resistant crops.
(Article: Masanori Nakajo)
