A 6′ gentamicin acetyltransferase gene allows effective selection of tobacco transformants using kanamycin as a substrate

Abstract

6' gentamicin acetyltransferases detoxify aminoglycoside antibiotics containing a 6' amino group. We tested whether a 6' gentamicin acetyltransferase gene (6' gat) of Shigella sp. is suitable as selectable gene in plant transformation using kanamycin (Km) as a substrate. A comparative transformation experiment using Nicotiana tabacum SR1 protoplasts showed that 6' gat is as effective for selection of transformants as the commonly used neomycin phosphotransferase II (nptII). In stably transformed plants we detected moderate levels of the 6' gat mRNA. An enzymatic assay was developed with which the acetyltransferase activity of the protein is easily demonstrated.

Manipulating Gene Expression for the Metabolic Engineering of Plants

“…Of course, proper expression of these enzymes requires that the genes encoding them be modified to resemble plant genes (proper promoters, polyadenylation signals, etc., see below). While kanamycin is perhaps the most widely used antibiotic for selection of transgenic plant tissues (Nap et al, 1992), resistance markers for antibiotics such as hygromycin, streptomycin, gentamicin, and chloramphenicol have also been routinely employed (Dale and Ow, 1991;Gossele et al, 1994;Maliga et al, 1988;Pietrzak et al, 1986;Rogers et al, 1983). The majority of these markers operate by chemically modifying the antibiotic itself, for example via phosphorylation or acetylation, rendering the compound inactive.…”

A transgene-centred approach to the biosafety of transgenic plants: overview of selection and reporter genes

“…( 1988) : aacA (6'gat) : Shigella sp. : aminoglycoside-6' -acetyltransferase (AAC(6')) : acetylation of the free 6' -amino moiety : gentamicin, kanamycin, tobramycin, neomycin , paromomycin, amikacin, netilmicin (aminoglycoside antibiotics) : impaired chloroplast protein synthesis : Gossele et a!. ( 1994) : AAC(6') is a large group of enzymes with a wide distribution .…”