Improvement in Nitrogen-Use Efficiency Increases Salt Stress Tolerance in Rice Seedlings and Grain Yield in Salinized Soil

作者：Ji Ping, Xu Chen, Fenglou Ling, Xingjie Li, Zexin Qi, Yunfeng Chen, Xiaolong Liu, Zhian Zhang, Jinze Wang, Zhiyang Luo, Zhen Cheng, Jianrui Chen · 发表于：Plants · 年份：2025 · DOI：10.3390/plants14040556 · 被引用次数：5 · 研究领域：Rice Cultivation and Yield Improvement、Silicon Effects in Agriculture、Plant nutrient uptake and metabolism

Salt stress has become a major limiting factor of rice (Oryza sativa L.) yield worldwide. Appropriate nitrogen application contributes to improvement in the salt tolerance of rice. Here, we show that improvement in nitrogen-use efficiency increases salt stress tolerance in rice. Rice varieties with different nitrogen-use efficiencies were subjected to salt stress; they were stimulated with 50, 100, and 150 mmol/L of NaCl solution at the seedling stage and subjected to salinities of 0.2, 0.4%, and 0.6% at the reproductive growth stage. Compared with nitrogen-inefficient rice varieties, the nitrogen-efficient rice varieties showed significant increases in the expression levels of nitrogen-use-efficiency-related genes (TOND1 and OsNPF6.1), nitrogen content (5.1–12.1%), and nitrogen-use enzyme activities (11.7–36.4%) when under salt stress conditions. The nitrogen-efficient rice varieties showed a better adaptation to salt stress, as shown by the decrease in leaf-withering rate (4.7–10.3%), the higher chlorophyll (3.8–9.7%) and water contents (1.1–9.2%), and the better root status (7.3–9.1%) found in the rice seedlings under salt stress conditions. Analysis of physiological indexes revealed that the nitrogen-efficient rice varieties accumulated higher osmotic adjustment substances (9.7–79.9%), lower ROS (23.1–190.8%) and Na+ (15.9–97.5%) contents, higher expression levels of salt stress-related genes in rice seedlings under salt stress conditions. Furthermore, the nitrogen-effici...