AFFINITY OF GLYCOLIPOPROTEIN FRACTION FROM POTATO SUSPENSION CELLS FOR THE TOXIN PRODUCED BY THE PATHOGEN CAUSING RING ROT

The receptors for a toxin produced by ring rot causal agent Clavibacte r michiganensis subsp. sepedonicus were isolated from a potato (Solanu m tuberosum. L.), cultivar Adretta, with a moderate resistance to this toxin. The toxin was shown to be a complex exopolysaccharide bearing nonprotein ninhydrin-positive groups. The fraction with high affinity for toxin, comprising carbohydrates, neutral lipids, glycolipids, and small amount of proteins, was eluted from potato cells by affinity col umn chromatography in the presence of Na-desoxycholate using stepwise gradients of pH and ion strength. The fact that micelles of this fract ion were capable of strong binding to fluorescein isothiocyanate-label ed toxin also confirmed the affinity of this fraction for toxin. These results allowed us to propose the possibility of interaction between the toxin and the molecular determinants on the cell wall and the rece ptors on the plasma membrane of potato cells.