As a single nitrogen source, ammonium (NH₄⁺) can inhibit the growth of plants, especially when applied in excess. Tandem mass tag (TMT) quantitative proteomics technology was employed in the current study to explore and analyze the mechanisms of ammonium-induced inhibition. F₁ tomato (Lycopersicon esculentum Mill) was used in this study. Seedlings at the four leaf-stages grown in a greenhouse were irrigated using nutrient solution with NH₄⁺-N as single nitrogen source (15 mmol L⁻¹, single NO₃⁻-N as control) for 5 weeks. Compared to the control, the root biomass of NH₄⁺-N-treated seedlings decreased by 50%. In addition, NH₄⁺ content in roots was 2.83-fold increased and soluble sugar and protein contents were increased. However, the starch content did not change significantly. The activities of glutamine synthetase (GS), glutamate synthetase (GOGAT) and glutamate dehydrogenase (GDH), which are involved in ammonium assimilation, were increased, and glutamine (Gln) content was also increased. However, glutamate (Glu) content, which is important for amino transfer, did not significantly increase. Ammonium assimilation was inhibited. Root quantitative proteomics showed that carbonic anhydrase Q5NE21 was significantly downregulated. Although K4BPV5 and K4D9J3 proteins, which improve ammonium assimilation, were upregulated, ammonium assimilation was limited. In addition, NH₄⁺ accumulated, which is likely due to Q5NE21 downregulation. Meanwhile, cell wall metabolism related to phenylpropanoid biosynthesis was altered due to the accumulation of NH₄⁺ levels. Subsequently, tomato root growth was inhibited.

铵（NH ₄ ⁺）作为单一氮源，可以抑制植物的生长，尤其是过量施用时。本研究采用串联质量标签（TMT）定量蛋白质组学技术来探索和分析铵诱导的抑制作用的机制。在这项研究中使用了F ₁番茄（番茄）。使用NH ₄ ⁺ -N作为单一氮源（15 mmol L ^-1，单一NO ₃ ^-- N作为对照）的营养液灌溉温室中四个叶期的幼苗，持续5周。与对照相比，NH ₄ ⁺的根系生物量-N处理的幼苗减少了50％。此外，NH ₄ ⁺根中的含量增加了2.83倍，可溶性糖和蛋白质含量增加了。但是，淀粉含量没有明显变化。氨同化作用涉及的谷氨酰胺合成酶（GS），谷氨酸合成酶（GOGAT）和谷氨酸脱氢酶（GDH）的活性增加，谷氨酰胺（Gln）的含量也增加。但是，对于氨基转移很重要的谷氨酸（Glu）含量并未显着增加。铵同化被抑制。根定量蛋白质组学显示碳酸酐酶Q5NE21明显下调。尽管提高铵同化的K4BPV5和K4D9J3蛋白被上调，但铵同化受到限制。此外，NH ₄ ⁺积累，这很可能是由于Q5NE21下调。同时，由于NH ₄ ⁺的积累，与苯丙烷生物合成有关的细胞壁代谢发生改变。随后，番茄根的生长受到抑制。