Phytoalexin sakuranetin functions in resistance against rice blast. However, the mechanisms underlying the effects of sakuranetin remains elusive. Here, we report that rice lines expressing resistance (R) genes were found to contain high levels of sakuranetin, which correlates with attenuated endocytic trafficking of plasma membrane (PM) proteins. Exogenous and endogenous sakuranetin attenuates the endocytosis of various PM proteins and the fungal effector PWL2. Moreover, accumulation of the avirulence protein AvrCO39, resulting from uptake into rice cells by Magnaporthe oryzae, was reduced following treatment with sakuranetin. Pharmacological manipulation of clathrin-mediated endocytic (CME) suggests that this pathway is targeted by sakuranetin. Indeed, attenuation of CME by sakuranetin is sufficient to convey resistance against rice blast. Our data reveals a mechanism of rice against M. oryzae by increasing sakuranetin levels and repressing the CME of pathogen effectors, which is distinct from the action of many R genes that mainly function by modulating transcription.

植物抗毒素 sakuranetin 具有抗稻瘟病的作用。然而，樱花素的作用机制仍然难以捉摸。在这里，我们报告发现表达抗性（R）基因的水稻品系含有高水平的樱花素，这与质膜（PM）蛋白的内吞运输减弱有关。外源性和内源性樱花素可减弱各种 PM 蛋白和真菌效应子 PWL2 的内吞作用。此外，由稻瘟病菌摄取到水稻细胞中而产生的无毒蛋白 AvrCO39 的积累在用 sakuranetin 处理后减少。网格蛋白介导的内吞作用 (CME) 的药理学操作表明，sakuranetin 是该通路的靶标。事实上，樱花素对 CME 的减弱作用足以表达对稻瘟病的抵抗力。我们的数据揭示了水稻通过增加樱花素水平和抑制病原体效应子的 CME 来对抗米霉的机制，这与许多主要通过调节转录发挥作用的 R 基因的作用不同。