Effect of Alachlor, Propachlor, and Prynachlor on GA₃-induced Production of Protease and α-Amylase

Alachlor [2-chloro-2′,6′-diethyl- N (methoxymethyl)-acetanilide], propachlor (2-chloro- N -isopropylacetanilide) and prynachlor [2-chloro- N -(1-methyl-2-propynyl)acetanilide], inhibited gibberellic acid (GA 3 ),-induced production of protease and α-amylase in deembryonated barley ( Hordeum vulgare L, ‘Schuyler’) seed. Production of protease was more sensitive to these herbicides than α-amylase. The degree of inhibition of protease and α-amylase production caused by alachlor was equivalent to that caused by cycloheximide, puromycin and actinomycin-D, known protein and nucleic acid synthesis inhibitors. Higher GA 3 concentrations reversed the inhibition of protease and α-amylase synthesis caused by alachlor but did not reduce the effect of alachlor on barley seed germination and growth. It is concluded that the inhibition of protease and α-amylase production by alachlor is perhaps only one of several effects on early seed germination and seedling development.