Reactive oxygen species (ROS) is a chemically reactive chemical substance containing oxygen and a natural by-product of normal oxygen metabolism. Excessive ROS affect the growth process of crops, which will lead to the decrease of yield. Nitrogen, as a critical nutrient element in plants and plays a vital role in plant growth and crop production. Nitrate is the primary nitrogen source available to plants in agricultural soil and various natural environments. However, the molecular mechanism of ROS-nitrate crosstalk is still unclear. In this study, we used the foxtail millet (Setaria italica L.) as the material to figure it out. Here, we show that excessive NaCl inhibits nitrate-promoted plant growth and nitrogen use efficiency (NUE). NaCl induces ROS accumulation in roots, and ROS inhibits nitrate-induced gene expression in a short time. Surprisingly, low concentration ROS slight promotes and high concentration of ROS inhibits foxtail millet growth under long-term H₂O₂ treatment. These results may open a new perspective for further exploration of ROS-nitrate signaling pathway in plants.

活性氧（ROS）是一种含有氧的化学活性化学物质，是正常氧代谢的天然副产物。过量的ROS会影响作物的生长过程，从而导致产量下降。氮作为植物的重要营养元素，在植物生长和农作物生产中发挥着至关重要的作用。硝酸盐是农业土壤和各种自然环境中植物可利用的主要氮源。然而，ROS-硝酸盐串扰的分子机制仍不清楚。在本研究中，我们以谷子（Setaria italica L.）为材料进行了研究。在这里，我们发现过量的氯化钠会抑制硝酸盐促进的植物生长和氮利用效率（NUE）。 NaCl诱导根部ROS积累，ROS在短时间内抑制硝酸盐诱导的基因表达。令人惊讶的是，在长期H ₂ O ₂处理下，低浓度ROS轻微促进谷子生长，而高浓度ROS抑制谷子生长。这些结果可能为进一步探索植物中ROS-硝酸盐信号通路开辟新的视角。