NITROGENASE ACTIVITY (C2H2 REDUCTION) OF AZORHIZOBIUM IN 2,4-D-INDUCED ROOT STRUCTURES OF WHEAT

The characteristics of C2H4 formation from C2H2 associated with 2,4-D- induced root structures on wheat seedlings inoculated with Azorhizobiu m caulinodans ORS571 have been investigated. Wheat seedlings treated w ith Azorhizobium plus 2,4-D were more tolerant in their C2H2 reduction activity to pO(2) 0.02 and 0.04 atm in the gas phase than wheat seedl ings inoculated with Azorhizobium alone. C2H3 production was C2H2 depe ndent and was strongly inhibited by ammonia and nitrite. The nitrogena se activity of A. caulinodans associated with the 2,4-D-induced root s tructures of wheat seedlings was also confirmed by the fixation of N-1 5(2).