Bacteria-mediated uptake of choline sulfate by plants: bacterial effectiveness.

The ability of bacteria to cause rapid uptake of choline sulfate in plants, i.e., effectiveness, was studied using Pseudomonas tolaasii and excised roots of barley (Hordeum vulgare L.). Once effective, bacteria remained so after being killed by treatments which cause little damage to their outer structure. However, effectiveness was destroyed by disruption of the cell wall, protein reagents, a mild heat treatment or removal of Mg2+. Effective bacteria adsorbed choline sulfate. This adsorption had characteristics similar to those of bacterial effectiveness (magnesium requirement, high substrate specificity). These results indicate that a proteinaceous structure on the bacterial surface binds and, somehow, transfers choline sulfate to the plant.