文献类型： 外文期刊

作者： Ma, Chao ¹ ; Ban, Tiantian ² ; Yu, Hongjun ³ ; Li, Qiang ³ ; Li, Xiaohui ² ; Jiang, Weijie ¹ ; Xie, Jianming ¹ ;

作者机构： 1.Gansu Agr Univ, Coll Hort, Lanzhou 730070, Gansu, Peoples R China

2.Guizhou Acad Agr Sci, Inst Hort, Guiyang 550006, Guizhou, Peoples R China

3.Chinese Acad Agr Sci, Inst Vegetables & Flowers, 12 Zhongguancun S St, Beijing 100081, Peoples R China

关键词： nitrogen forms; cucumber; nitrogen metabolism; gene expression

期刊名称：AGRONOMY-BASEL （ 影响因子：3.417； 五年影响因子：3.64 ）

ISSN： 2073-4395

年卷期： 2019 年 9 卷 5 期

页码：

收录情况： SCI

摘要： Nitrogen (N) forms include ammonium [NH4+-N], nitrate [NO3--N], and urea [CO(NH2)(2)]. Urea is the most common nitrogen fertilizer in agriculture due to its inexpensive price and high N content. Although the reciprocal influence between NO3--N and NH4+-N is well known, CO(NH2)(2) interactions with these inorganic N forms have been poorly studied. We studied the effects of different nitrogen forms with equal nitrogen on dry matter, yield, enzyme activity, and gene expression levels in cucumber. NO3--N treatment with equal CO(NH2)(2) promoted nitrate reduction, urea utilization, and the GS/GOGAT cycle but reduced the nitrate content. UR-2, NR-2, NR-3, NiR, GOGAT-1-1, and GS-4 were upregulated in response to these changes. NH4+-N treatment with equal CO(NH2)(2) promoted nitrogen metabolism and relieved the ammonia toxicity of pure NH4+-N treatment. UR-2, GOGAT-2-2, and GS-4 were upregulated, and GDH-3 was downregulated in response to these changes. Treatment with both NO3--N with added equal CO(NH2)(2) and NH4+-N with added equal CO(NH2)(2) enhanced the activities of GOGAT, GS, and UR and the amino acid pathway of urea metabolism; manifested higher glutamate, protein, chlorophyll, and nitrogen contents; and improved dry matter weight. A greater proportion of dry matter was distributed to the fruit, generating significantly higher yields. Therefore, the addition of urea to ammonium or nitrate promoted N metabolism and N utilization in cucumber plants, especially treatments with 50% NO3--N + 50% CO(NH2)(2), as the recommended nitrogen form in this study.