%0 Journal Article %A Jiang Hongzhen %A Wang Yamei %A Lai Liuru %A Liu Xintong %A Miao Changjian %A Liu Ruifang %A Li Xiaoyun %A Tan Jinfang %A Gao Zhenyu %A Chen Jingguang %T OsAMT1.1 Expression by Nitrate-Inducible Promoter of OsNAR2.1 Increases Nitrogen Use Efficiency and Rice Yield %D 2023 %R 10.1016/j.rsci.2023.03.006 %J Rice Science %P 222-234 %V 30 %N 3 %X

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.

%U http://www.ricesci.org/EN/10.1016/j.rsci.2023.03.006