Abstract
The metabolism of the herbicide L-phosphinothricin (L-Pt) was analyzed in tobacco (Nicotiana tabacum), alfalfa (Medicago sativa), and carrot (Daucus carota). In transgenic, Pt-resistant plants expressing the Pt-N-acetyltransferase gene (pat), L-Pt was acetylated, resulting in two forms of N-acetyl-Pt (ac-Pt). In transgenic plants expressing only low pat-encoded acetylating activity as well as in genetically unmodified plants, three metabolic compounds 4-methylphosphinico-2-oxo-butanoic acid, 3-methylphosphinico-propanoic acid (MPP), and 4-methylphosphinico-2-hydroxy-butanoic acid (MHB) were identified. Hence, the transgene-encoded acetylation of L-Pt competes with a plant-specific degradation. The compounds MPP, MHB, and ac-Pt were found to be the final, stable products of the plant's metabolic pathways. The mobility of these stable compounds in the plant was investigated: L-Pt as well as the derived metabolites were found to be preferentially transported to the upper regions of the plant.
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- Bartsch K., Tebbe C. C. Initial steps in the degradation of phosphinothricin (glufosinate) by soil bacteria. Appl Environ Microbiol. 1989 Mar;55(3):711–716. doi: 10.1128/aem.55.3.711-716.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bayer E., Gugel K. H., Hägele K., Hagenmaier H., Jessipow S., König W. A., Zähner H. Stoffwechselprodukte von Mikroorganismen. 98. Phosphinothricin und Phosphinothricyl-Alanyl-Alanin. Helv Chim Acta. 1972 Jan 31;55(1):224–239. doi: 10.1002/hlca.19720550126. [DOI] [PubMed] [Google Scholar]
- Block M. D., Botterman J., Vandewiele M., Dockx J., Thoen C., Gosselé V., Movva N. R., Thompson C., Montagu M. V., Leemans J. Engineering herbicide resistance in plants by expression of a detoxifying enzyme. EMBO J. 1987 Sep;6(9):2513–2518. doi: 10.1002/j.1460-2075.1987.tb02537.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lacoste A. M., Mansour S., Cassaigne A., Neuzil E. Effect of phosphonic analogues of glutamic acid on glutamate decarboxylase. Experientia. 1985 May 15;41(5):643–644. doi: 10.1007/BF02007699. [DOI] [PubMed] [Google Scholar]
- Lejczak B., Starzemska H., Mastalerz P. Inhibition of rat liver glutamine synthetase by phosphonic analogues of glutamic acid. Experientia. 1981 May 15;37(5):461–462. doi: 10.1007/BF01986133. [DOI] [PubMed] [Google Scholar]
- Logusch E. W., Walker D. M., McDonald J. F., Franz J. E. Substrate variability as a factor in enzyme inhibitor design: inhibition of ovine brain glutamine synthetase by alpha- and gamma-substituted phosphinothricins. Biochemistry. 1989 Apr 4;28(7):3043–3051. doi: 10.1021/bi00433a046. [DOI] [PubMed] [Google Scholar]
- Strauch E., Wohlleben W., Pühler A. Cloning of a phosphinothricin N-acetyltransferase gene from Streptomyces viridochromogenes Tü494 and its expression in Streptomyces lividans and Escherichia coli. Gene. 1988;63(1):65–74. doi: 10.1016/0378-1119(88)90546-x. [DOI] [PubMed] [Google Scholar]
- Wohlleben W., Arnold W., Broer I., Hillemann D., Strauch E., Pühler A. Nucleotide sequence of the phosphinothricin N-acetyltransferase gene from Streptomyces viridochromogenes Tü494 and its expression in Nicotiana tabacum. Gene. 1988 Oct 15;70(1):25–37. doi: 10.1016/0378-1119(88)90101-1. [DOI] [PubMed] [Google Scholar]