Plant immunity often penalizes growth and yield. The transcription factor Ideal Plant Architecture 1 (IPA1) reduces unproductive tillers and increases grains per panicle, which results in improved rice yield. Here we report that higher IPA1 levels enhance immunity. Mechanistically, phosphorylation of IPA1 at amino acid Ser163 within its DNA binding domain occurs in response to infection by the fungus Magnaporthe oryzae and alters the DNA binding specificity of IPA1. Phosphorylated IPA1 binds to the promoter of the pathogen defense gene WRKY45 and activates its expression, leading to enhanced disease resistance. IPA1 returns to a nonphosphorylated state within 48 hours after infection, resuming support of the growth needed for high yield. Thus, IPA1 promotes both yield and disease resistance by sustaining a balance between growth and immunity.
植物免疫通常以“牺牲”生长和产量为代价。转录因子“理想株型IPA1”能减少无效分蘖并增加每穗粒数，从而提高水稻产量。本文，我们报道了更高水平的IPA1能增强免疫能力。机械地，IPA1在其DNA结合结构域内的氨基酸Ser163处的磷酸化响应于稻瘟病菌（Magnaporthe oryzae）的感染而发生，并改变IPA1的DNA结合特异性。机械地，稻瘟病菌侵染后，IPA1在其DNA结合结构域内的第163位氨基酸Ser被磷酸化，并改变IPA1的DNA结合特异性。磷酸化的IPA1结合到病原体防御基因WRKY45的启动子，并激活其表达，导致抗病性增强。IPA1在侵染48小时内恢复到非磷酸化状态，以保证水稻高产所需要的生长。因此，IPA1通过维持生长和免疫之间的平衡来促进产量和抗病性。