FG Synthetic Microbiology, Institute for Biotechnology, BTU Cottbus-Senftenberg, Senftenberg, 01968, Germany.
Institute of Environmental Technology, Chair of Biotechnology of Water Treatment, BTU Cottbus-Senftenberg, Cottbus, 03046, Germany.
Environ Microbiol. 2021 Jun;23(6):2891-2905. doi: 10.1111/1462-2920.15534. Epub 2021 Jun 2.
Glyphosate is a nonselective herbicide that kills weeds and other plants competing with crops. Glyphosate specifically inhibits the 5-enolpyruvyl-shikimate-3-phosphate (EPSP) synthase, thereby depleting the cell of EPSP serving as a precursor for biosynthesis of aromatic amino acids. Glyphosate is considered to be toxicologically safe for animals and humans. Therefore, it became the most-important herbicide in agriculture. However, its intensive application in agriculture is a serious environmental issue because it may negatively affect the biodiversity. A few years after the discovery of the mode of action of glyphosate, it has been observed that bacteria evolve glyphosate resistance by acquiring mutations in the EPSP synthase gene, rendering the encoded enzyme less sensitive to the herbicide. The identification of glyphosate-resistant EPSP synthase variants paved the way for engineering crops tolerating increased amounts of the herbicide. This review intends to summarize the molecular mechanisms underlying glyphosate resistance in bacteria. Bacteria can evolve glyphosate resistance by (i) reducing glyphosate sensitivity or elevating production of the EPSP synthase, by (ii) degrading or (iii) detoxifying glyphosate and by (iv) decreasing the uptake or increasing the export of the herbicide. The variety of glyphosate resistance mechanisms illustrates the adaptability of bacteria to anthropogenic substances due to genomic alterations.
草甘膦是一种非选择性除草剂，可杀死杂草和其他与作物竞争的植物。草甘膦特异性抑制 5-烯醇丙酮酰莽草酸-3-磷酸（EPSP）合酶，从而耗尽作为芳香族氨基酸生物合成前体的 EPSP 细胞。草甘膦被认为对动物和人类在毒理学上是安全的。因此，它成为农业中最重要的除草剂。然而，由于它可能对生物多样性产生负面影响，因此其在农业中的大量应用是一个严重的环境问题。在发现草甘膦作用模式几年后，人们观察到细菌通过在 EPSP 合酶基因中获得突变而进化出抗草甘膦性，从而使编码的酶对除草剂的敏感性降低。鉴定出抗草甘膦的 EPSP 合酶变体为工程作物耐受增加剂量的除草剂铺平了道路。本文旨在总结细菌中抗草甘膦性的分子机制。细菌可以通过以下几种方式进化出抗草甘膦性：（i）降低草甘膦的敏感性或提高 EPSP 合酶的产量，（ii）降解或（iii）解毒草甘膦，以及（iv）减少除草剂的摄取或增加其外排。抗草甘膦性机制的多样性说明了细菌由于基因组改变而对人为物质的适应性。
