The effect of acetanilide herbicides on photosynthesis and respiration in isolated hypocotyl-epicotyl cells from threePhaseolustaxa

Abstract

The effect of alachlor [2-chloro-N-(2,6 diethylphenyl)-N-methoxymethyl) acetamide], metolachlor [2-chloro-N- (2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl) acetamide] and acetochlor [2-chloro-N-(ethoxymethyl)-N-(2-ethyl-6-methylphenyl) acetamide] on photosynthesis and respiration of isolated 10-day-old hypocotyl-epicotyl cells from three Phaseolus taxa was investigated. Herbicide concentrations of 1×10−12, 1×10−10, 1×10−8, 1×10−6,1×10−4 and 5×10−3 M were used. In most instances, both processes were stimulated by these herbicides. The highest stimulation of photosynthesis was found with metolachlor on Kamberg dry beans (328%), while inhibition of the same process by 25% occurred with Kidney beans. Respiration of Kidney beans was stimulated by a maximum of 39% using metolachlor but inhibited by 12% in the case of Kamberg beans. The tendency was for these herbicides to stimulate photosynthesis and respiration. Respiration, however, was not as strongly stimulated as photosynthesis. Results suggest that ...