Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK.
Department of Plant Sciences, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, UK.
Science. 2017 Jun 16;356(6343):1175-1178. doi: 10.1126/science.aan0081. Epub 2017 Jun 8.
Plants form beneficial associations with arbuscular mycorrhizal fungi, which facilitate nutrient acquisition from the soil. In return, the fungi receive organic carbon from the plants. The transcription factor RAM1 (REQUIRED FOR ARBUSCULAR MYCORRHIZATION 1) is crucial for this symbiosis, and we demonstrate that it is required and sufficient for the induction of a lipid biosynthetic pathway that is expressed in plant cells accommodating fungal arbuscules. Lipids are transferred from the plant to mycorrhizal fungi, which are fatty acid auxotrophs, and this lipid export requires the glycerol-3-phosphate acyltransferase RAM2, a direct target of RAM1. Our work shows that in addition to sugars, lipids are a major source of organic carbon delivered to the fungus, and this is necessary for the production of fungal lipids.
植物与丛枝菌根真菌形成有益的共生关系，这有助于从土壤中获取营养。作为回报，真菌从植物中获得有机碳。转录因子 RAM1（丛枝菌根共生 1 必需）对于这种共生关系至关重要，我们证明它对于诱导在容纳真菌丛枝的植物细胞中表达的脂质生物合成途径是必需且充分的。脂质从植物转移到真菌，真菌是脂肪酸营养缺陷型，这种脂质输出需要甘油-3-磷酸酰基转移酶 RAM2，它是 RAM1 的直接靶标。我们的工作表明，除了糖之外，脂质是输送给真菌的有机碳的主要来源，这对于真菌脂质的产生是必要的。
