Phosphorus and nitrogen are essential macronutrients for plant growth and crop production. During phosphate (Pi) starvation, plants enhanced Pi but reduced nitrate (NO₃^–) uptake capacity, and the mechanism is unclear. Here, we show that a GARP-type transcription factor NITRATE-INDUCIBLE, GARP-TYPE TRANSCRIPTIOANL REPRESSOR1.2 (NIGT1.2) coordinately modulates Pi and NO₃^– uptake in response to Pi starvation. Overexpression of NIGT1.2 increased Pi uptake capacity but decreased NO₃^– uptake capacity in Arabidopsis (Arabidopsis thaliana). Furthermore, the nigt1.1 nigt1.2 double mutant displayed reduced Pi uptake but enhanced NO₃^– uptake under low-Pi stress. During Pi starvation, NIGT1.2 directly up-regulated the transcription of the Pi transporter genes PHOSPHATE TRANSPORTER1;1 (PHT1;1) and PHOSPHATE TRANSPORTER1;4 (PHT1;4) and down-regulated expression of NO₃^– transporter gene NITRATE TRANSPORTER1.1 (NRT1.1) by binding to cis-elements in their promoters. Further genetic assays demonstrated that PHT1;1, PHT1;4, and NRT1.1 were genetically epistatic to NIGT1.2. We also identified similar regulatory pathway in maize (Zea mays). These data demonstrate that the transcription factor NIGT1.2 plays a central role in modulating low-Pi-dependent uptake of Pi and NO₃^–, tending toward maintenance of the phosphorus to nitrogen balance in plants during Pi starvation.

磷和氮是植物生长和农作物生产必需的常量营养素。在磷酸盐（Pi）饥饿期间，植物增强Pi但降低硝酸盐（NO ₃ ^-）吸收能力，其机制尚不清楚。在这里，我们展示了 GARP 型转录因子 NITRATE-INDUCIBLE、GARP-TYPE TRANSCRIPTIOANL REPRESSOR1.2 (NIGT1.2) 协调调节 Pi 和 NO ₃ ^–摄取以响应 Pi 饥饿。NIGT1.2的过表达增加了拟南芥 ( Arabidopsis thaliana )的 Pi 吸收能力，但降低了 NO ₃ ^{-吸收能力。}此外，nigt1.1 nigt1.2双突变体表现出 Pi 吸收减少，但 NO _3增强^–低 Pi 压力下的吸收。在Pi饥饿期间，NIGT1.2直接上调Pi转运蛋白基因磷酸转运蛋白1;1（PHT1;1）和磷酸转运蛋白1;4（PHT1;4）的转录，并下调NO ³_转运蛋白基因硝酸转运蛋白1的表达.1 ( NRT1.1 ) 通过结合到其启动子中的顺式元件。进一步的遗传分析表明，PHT1;1、PHT1;4和NRT1.1在遗传上与NIGT1.2具有上位性。我们还在玉米中发现了类似的调控途径（玉米）。_{这些数据表明，转录因子 NIGT1.2 在调节 Pi 和 NO 3} ^–的低 Pi 依赖性吸收中发挥着核心作用，有助于在 Pi 饥饿期间维持植物中的磷氮平衡。