ALACHLOR REGULATION OF MAIZE GLUTATHIONE-S-TRANSFERASE GENES

Glutathione S-transferases are a family of isozymes involved in herbic ide 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. A ll of them, in particular Gst-27, have been shown to play a role in th e 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 differe nt susceptibility to the herbicide, and we show that each gene is char acterised by a specific pattern of expression. In particular, the stro ng 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) 1 998 Academic Press.