Rice Science ›› 2023, Vol. 30 ›› Issue (3): 222-234.DOI: 10.1016/j.rsci.2023.03.006

• Research Paper • Previous Articles     Next Articles

OsAMT1.1 Expression by Nitrate-Inducible Promoter of OsNAR2.1 Increases Nitrogen Use Efficiency and Rice Yield

Jiang Hongzhen1,#, Wang Yamei1,#, Lai Liuru1, Liu Xintong1, Miao Changjian1, Liu Ruifang2, Li Xiaoyun1, Tan Jinfang1, Gao Zhenyu3(), Chen Jingguang1()   

  1. 1School of Agriculture, Shenzhen Campus of Sun Yat-sen University, Shenzhen 518107, China
    2The High School Affiliated to Renmin University of China, Shenzhen 518119, China
    3China National Rice Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou 310006, China
  • Received:2022-10-17 Accepted:2023-01-14 Online:2023-05-28 Published:2023-02-21
  • Contact: Chen Jingguang (chenjg28@mail.sysu.edu.cn); Gao Zhenyu (gaozhenyu@caas.cn)
  • About author:First author contact:#These authors contributed equally to this work


Nitrate (NO3-) and ammonium (NH4+) are two main inorganic nitrogen (N) sources during crop growth. Here, we enhanced the expression of OsAMT1.1, which encodes a NH4+ transporter, using the NO3--inducible promoter of OsNAR2.1 and an ubiquitin promoter in transgenic rice plants. Under field condition of 120 kg /hm2 N, agronomic N use efficiency, N recovery efficiency and N transport efficiency, and grain yield of the pOsNAR2.1:OsAMT1.1 transgenic lines were increased compared with those of the wild type (WT) and the pUbi:OsAMT1.1 transgenic plants. Under 2.0 mmol/L NO3- + 0.5 mmol/L NH4+ and 0.5 mmol/L NO3- + 2.0 mmol/L NH4+ conditions of hydroponic culture, compared with the WT, both biomass and total N content were increased in the pOsNAR2.1:OsAMT1.1 transgenic lines. However, biomass was significantly reduced in pUbi:OsAMT1.1 transgenic plants under 0.5 mmol/L NO3- + 2.0 mmol/L NH4+ condition. The lines expressing pOsNAR2.1:OsAMT1.1 exhibited increased OsAMT1.1 expression and 15NH4+ influx in roots under both 2.0 mmol/L NO3- + 0.5 mmol/L NH4+ and 0.5 mmol/L NO3- + 2.0 mmol/L NH4+ conditions. Our study showed that expression of OsAMT1.1 can be promoted when driven by the OsNAR2.1 promoter, especially under high-level nitrate condition, leading to enhancement of NH4+ uptake, N use efficiency and grain yield.

Key words: OsAMT1.1, OsNAR2.1 promoter, nitrogen use efficiency, yield, rice