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“犧牲”生長和產(chǎn)量為代價。轉(zhuǎn)錄因子“理想株型IPA1”能減少無效分蘗并增加每穗粒數(shù)，從而提高水稻產(chǎn)量。本文，我們報道了更高水平的IPA1能增強免疫能力。機械地，IPA1在其DNA結(jié)合結(jié)構(gòu)域內(nèi)的氨基酸Ser163處的磷酸化響應(yīng)于稻瘟病菌（Magnaporthe oryzae）的感染而發(fā)生，并改變IPA1的DNA結(jié)合特異性。機械地，稻瘟病菌侵染后，IPA1在其DNA結(jié)合結(jié)構(gòu)域內(nèi)的第163位氨基酸Ser被磷酸化，并改變IPA1的DNA結(jié)合特異性。磷酸化的IPA1結(jié)合到病原體防御基因WRKY45的啟動子，并激活其表達，導(dǎo)致抗病性增強。IPA1在侵染48小時內(nèi)恢復(fù)到非磷酸化狀態(tài)，以保證水稻高產(chǎn)所需要的生長。因此，IPA1通過維持生長和免疫之間的平衡來促進產(chǎn)量和抗病性。