Physiological Responses to Fluazifop-Butyl in Tissue of Corn (Zea mays) and Soybean (Glycine max)

Abstract

Effects of fluazifop-butyl {(±)-butyl 2-[4-[(5-(trifluoromethyl)-2-pyridinyl)oxy] phenoxy] propanoate} on cellular uptake and incorporation of14C-leucine,14C-uridine, and14C-thymidine into protein, RNA, and DNA, respectively, were evaluated in corn (Zea maysL.) coleoptiles and soybean [Glycine max(L.) Merr.] hypocotyls. Uptake of14C-leucine in corn coleoptiles was inhibited by fluazifop-butyl at 10-4to 10-7M, which was related to reductions in incorporation of14C-leucine into protein at 10-4to 10-6M. The effect of fluazifop-butyl on14C-leucine uptake and incorporation was reduced by 2 × 10-6M 2,4-D [(2,4-dichlorophenoxy)acetic acid], indicating antagonism between these herbicides. RNA and DNA synthesis were inhibited at 10-5and 10-4M. Protein synthesis in soybean hypocotyls was stimulated by 10-7and 10-6M fluazifop-butyl 33 and 27%, respectively, and inhibited by 10-4M 50%. RNA and DNA synthesis were also inhibited by 10-4M in soybean.