CHARACTERIZATION AND PURIFICATION OF HERBICIDE NAPROANILIDE RECEPTOR FROM TOBACCO MESOPHYLL CALLUS

Herbicide naproanilide receptor proteins in tobacco mesophyll callus w ere isolated and characterized. The reaction between naproanilide and its receptor proteins is a specific binding with dissociation constant K-d = 1.8 x 10(-7) M. The optimum conditions for the binding reaction are 0-4 degrees C at pH 5.8-7.8 for 30-45 min. Purification of naproa nilide receptor proteins on a chromatograph with Sepharose 6B gel filt ration, DEAE-Sephacel ion exchange and NOP-epsilon-L-lysine-Sepharose 4B affinity columns in sequence revealed the molar mass 48 kDa. Purifi ed naproanilide receptor exhibited no stimulation on RNA synthesis, an d the results indicated that the receptor may be only a carrier for ab sorption and translocation of plant hormone but cannot enter nuclei fo r RNA synthesis and regulation of gene expression.