Droge-Laser W., Siemeling U., Puhler A., Broer I.
Lehrstuhl fur Genetik, Fakultat fur Biologie (W.D.-L., A.P., I.B.), and Lehrstuhl fur Anorganische Chemie III (U.S.), Universitat Bielefeld, Universitatsstrasse, 33615 Bielefeld, Germany.
Plant Physiol. 1994 May;105(1):159-166. doi: 10.1104/pp.105.1.159.
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.
对除草剂L-草铵膦（L-Pt）在烟草（烟草属）、苜蓿（紫花苜蓿）和胡萝卜（胡萝卜属）中的代谢情况进行了分析。在表达Pt-N-乙酰转移酶基因（pat）的抗Pt转基因植物中，L-Pt被乙酰化，产生了两种形式的N-乙酰-Pt（ac-Pt）。在仅表达低水平pat编码的乙酰化活性的转基因植物以及未进行基因修饰的植物中，鉴定出了三种代谢化合物4-甲基膦酰基-2-氧代丁酸、3-甲基膦酰基丙酸（MPP）和4-甲基膦酰基-2-羟基丁酸（MHB）。因此，转基因编码的L-Pt乙酰化与植物特异性降解相互竞争。发现化合物MPP、MHB和ac-Pt是植物代谢途径的最终稳定产物。研究了这些稳定化合物在植物中的移动性：发现L-Pt及其衍生代谢物优先运输到植物的上部区域。
