Hunan Weed Science Key Laboratory, Hunan Academy of Agricultural Sciences, 410125 Changsha, China.
College of Plant Protection, Hunan Agricultural University, 410128 Changsha, China.
Proc Natl Acad Sci U S A. 2021 Apr 20;118(16). doi: 10.1073/pnas.2100136118.
Glyphosate is the most widely used herbicide in world agriculture and for general vegetation control in a wide range of situations. Global and often intensive glyphosate selection of very large weedy plant populations has resulted in widespread glyphosate resistance evolution in populations of many weed species. Here, working with a glyphosate-resistant (GR) population that evolved in a Western Australia agricultural field, we identified an ATP-binding cassette (ABC) transporter () that is consistently up-regulated in GR plants. When expressed in transgenic rice, this transporter endowed glyphosate resistance. Equally, rice, maize, and soybean overexpressing the ortholog genes were made resistant to glyphosate. Conversely, CRISPR/Cas9-mediated knockout of the ortholog gene increased rice susceptibility to glyphosate. Subcellular localization analysis and quantification of glyphosate cellular levels in treated transgenic rice plants and isolated leaf protoplasts as well as structural modeling support that EcABCC8 is likely a plasma membrane-localized transporter extruding cytoplasmic glyphosate to the apoplast, lowering the cellular glyphosate level. This is a report of a membrane transporter effluxing glyphosate in a GR plant species, and its function is likely conserved in crop plant species.
草甘膦是世界农业中使用最广泛的除草剂，也是广泛情况下控制一般植被的常用除草剂。在全球范围内，经常进行高强度的草甘膦选择，导致许多杂草物种的种群中广泛出现了草甘膦抗性的进化。在这里，我们与在澳大利亚西部农业田地里进化出的抗草甘膦（GR）种群合作，鉴定出一种不断在 GR 植物中上调的 ATP 结合盒（ABC）转运蛋白（）。当在转基因水稻中表达时，这种转运蛋白赋予了草甘膦抗性。同样，过表达 同源基因的水稻、玉米和大豆也对草甘膦具有抗性。相反，利用 CRISPR/Cas9 介导的 同源基因的敲除增加了水稻对草甘膦的敏感性。对转基因水稻植物和分离的叶原生质体进行的亚细胞定位分析和草甘膦细胞水平的定量以及结构建模支持 EcABCC8 可能是一种定位于质膜的转运蛋白，将细胞质中的草甘膦外排到质外体，降低细胞内草甘膦水平。这是关于在 GR 植物物种中排出草甘膦的膜转运蛋白的报告，其功能在作物植物物种中可能是保守的。
