Alachlor Regulation of Maize Glutathione S-Transferase Genes

Glutathione S-transferases are a family of isozymes involved in herbicide detoxification in several plant species. In maize three Gst genes, designated Gst-29, Gst-27, and Gst-26 according to the molecular mass of the polypeptides they encode, have been characterised in detail. All of them, in particular Gst-27, have been shown to play a role in the metabolism of the chloroacetanilide herbicide alachlor. In this work we analyse the transcript accumulation of these genes after alachlor treatment in roots and leaves of three maize inbred lines with different susceptibility to the herbicide, and we show that each gene is characterised by a specific pattern of expression. In particular, the strong Gst-27 mRNA accumulation in both tissues of alachlor-treated plants confirms the central role of this gene in response to this herbicide and suggests the existence of a switchable regulation mechanism. (C) 1998 Academic Press.