- •Grass plants bind prions from contaminated brain and excreta
- •Prions from different strains and species remain bound to living
plants
- •Hamsters fed with prion-contaminated plant samples develop prion
disease
- •Stems and leaves from grass plants grown in infected soil contain
prions
Summary
Prions are the protein-based infectious agents responsible for prion
diseases. Environmental prion contamination has been implicated in disease
transmission. Here, we analyzed the binding and retention of infectious
prion protein (PrPSc) to plants. Small quantities of PrPSc contained in
diluted brain homogenate or in excretory materials (urine and feces) can
bind to wheat grass roots and leaves. Wild-type hamsters were efficiently
infected by ingestion of prion-contaminated plants. The prion-plant
interaction occurs with prions from diverse origins, including chronic
wasting disease. Furthermore, leaves contaminated by spraying with a
prion-containing preparation retained PrPSc for several weeks in the living
plant. Finally, plants can uptake prions from contaminated soil and
transport them to aerial parts of the plant (stem and leaves). These
findings demonstrate that plants can efficiently bind infectious prions and
act as carriers of infectivity, suggesting a possible role of environmental
prion contamination in the horizontal transmission of the disease.