November 25, 2016
A new defense mechanism discovered and elucidated
Researchers have found that when pathogens infect plants, the plants can recover extracellular sugars through enhanced glucose absorption, inhibiting access to sugars the pathogens use for energy and to enhance their virulence. The findings came out of a collaborative research project between RIKEN CSRS, Kyoto University, Tokushima University and the Nara Institute of Science and Technology.
When a pathogen infects a plant, it absorbs sugars the plant has accumulated through photosynthesis, mainly for use as a carbon source. Although pathogen exploitation of plant sugars is a known phenomenon, it was unclear whether plants possess a counteracting mechanism. The research group thought that perhaps cells could be transferring extracellular sugars internally to prevent their use by pathogenic bacteria and decided to investigate plant cell sugar uptake at the time of defense mechanism activation in Arabidopsis thaliana. Analysis revealed defense response activation enhanced glucose transporter activity and decreased extracellular sugar content, which led to inhibition of virulence factor secretion and limited the pathogen’s metabolic energy sources, resulting in suppressed bacterial growth.
The group’s finding suggest that discovery of a compound capable of enhancing sugar absorption could lead to the development of new pesticides that would be effective against a wider range of pathogens.
K. Yamada, Y. Saijo, H. Nakagami, Y. Takano,
"Regulation of sugar transporter activity for antibacterial defense in Arabidopsis".
Plant Proteomics Research Unit