Effects of exogenous L-Glutamine as a sole nitrogen source on physiological characteristics and nitrogen use efficiency of poplar
Effects of exogenous L-Glutamine as a sole nitrogen source on physiological characteristics and nitrogen use efficiency of poplar
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外源L-谷氨酰胺作为唯一氮源对杨树生理特性及氮素利用效率的影响
DOI：
10.1016/j.plaphy.2021.12.032
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发表时间：
2022-01-07
影响因子：
6.5
通讯作者：
Su, Tao
中科院分区：
文献类型：
--
作者：
Han, Mei;Xu, Mingyue;Su, Tao
谷氨酰胺（Gln）是一种蛋白质氨基酸、氮转运蛋白和氨载体，参与多种重要分子的合成途径。然而，外源谷氨酰胺对植物生长发育的影响在很大程度上仍然未知。以不同浓度的谷氨酰胺（Gln）作为唯一氮源，对杂交白杨“南林895”培养基进行了研究。阐述了不同浓度的有机肥对白杨生长、光合作用、氮代谢相关酶及代谢产物的影响。引人注目的是，0.5 mM谷氨酰胺喂养的杨树没有表现出相当大的增长妥协相比，无机N控制（CK-N），即使他们的N供应水平只有一半的CK-N控制。更重要的是，他们的NUE得到了增强。此外，0.5 mM谷氨酰胺处理显着增加了根中的氨基酸与可溶性糖的协调含量，而在叶片中观察到的边际效应相比CK-N。与此相反，高浓度Gln（> 0.5 mM）处理导致杨树根系中氨基酸和淀粉积累增加，可溶性糖含量降低，对白杨生物量、光合作用、酶活性和NUE产生不利影响，从而抑制白杨生长。总的来说，这些研究结果使我们能够推断，白杨植物有能力采取和利用谷氨酰胺作为唯一的N源。当施用量适当时，谷氨酰胺能促进氮、碳的动态平衡，具有较高的氮素利用效率、较低的氮素输入量和较高的生物相容性，因而具有良好的生长性能和环境效益。
L-Glutamine (Gln) is a proteinogenic amino acid, N transporter and NH3 carrier, engaging in diversified pathways for synthesizing many important molecules. However, the effects of exogenous Gln on plant growth and development remain largely unknown. In this study, different concentrations of Gln were supplemented in the poplar hybrid 'Nanlin895' culture medium as a sole N source. Their effects on poplar growth, photosynthesis, N metabolism-related enzymes and metabolites were elucidated. Strikingly, 0.5 mM Gln-fed poplars showed no considerable growth compromise compared to the inorganic N control (CK-N), even though their N supply level was only half that of the CK-N control. What's more, their NUE was enhanced. In addition, 0.5 mM Gln treatment significantly increased the contents of amino acids in coordination with soluble sugars in the roots, while marginal effects in the leaves were observed compared to CK-N. By contrast, applying a high level of Gln (> 0.5 mM) resulted in larger accumulation of amino acids and starch, but lower level of soluble sugars, particularly in the roots, followed by adverse effects on poplar biomass, photosynthesis, enzyme activities and NUE; consequently, poplar growth was inhibited. Collectively, these findings allow us to deduce that poplar plants are competent to take up and utilize Gln as a sole N source. When applied at an appropriate level, Gln could promote a dynamic equilibrium of N and C, conferring sound growth performance and additional benefit for the environment as indicated by higher NUE, lower N input and higher biocompatible nature than the inorganic N.