NMT历史上的今天丨JXB杨树氮代谢研究文章发表

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NMT历史上的今天

2012年8月20日，西北农林科技大学罗志斌、罗杰利用NMT在Journal of Experimental Botany上发表了标题为Nitrogen metabolism of two contrasting poplar species during acclimation to limiting nitrogen availability的研究成果。

 

• 期刊：Journal of Experimental Botany
• 主题：两种对比杨树的氮代谢适应限制氮的有效性
• 标题：Nitrogen metabolism of two contrasting poplar species during acclimation to limiting nitrogen availability
• 影响因子：5.242
• 检测指标：NH₄⁺、NO₃^-、H⁺流速
• 检测部位：杨树根（距离根尖15mm）
• NH₄⁺、NO₃^-、H⁺流实验处理方法：杨树幼苗，不同N浓度（10、100、1000μM NH4NO3）处理3周
• NH₄⁺、NO₃^-、H⁺流实验测试液成份：0.01/0.1/1.0 mM NH4NO3，0.1 mM KCl, 0.1 mM CaCl2, pH 5.5
• 通讯作者：西北农林科技大学罗志斌、罗杰

英文摘要

To investigate N metabolism of two contrasting Populus species in acclimation to low N availability, saplings of slow-growing species (Populus popularis, Pp) and a fast-growing species (Populus alba × Populus glandulosa, Pg) were exposed to 10, 100, or 1000 μM NH₄NO₃. Despite greater root biomass and fine root surface area in Pp, lower net influxes of NH₄⁺ and NO₃^– at the root surface were detected in Pp compared to those in Pg, corresponding well to lower NH₄⁺ and NO₃^– content and total N concentration in Pp roots.

Meanwhile, higher stable N isotope composition (δ15N) in roots and stronger responsiveness of transcriptional regulation of 18 genes involved in N metabolism were found in roots and leaves of Pp compared to those of Pg.

These results indicate that the N metabolism of Pp is more sensitive to decreasing N availability than that of Pg. In both species, low N treatments decreased net influxes of NH₄⁺ and NO₃^–, root NH₄⁺ and foliar NO₃^– content, root NR activities, total N concentration in roots and leaves, and transcript levels of most ammonium (AMTs) and nitrate (NRTs) transporter genes in leaves and genes involved in N assimilation in roots and leaves. Low N availability increased fine root surface area, foliar starch concentration, δ15N in roots and leaves, and transcript abundance of several AMTs (e.g. AMT1;2) and NRTs (e.g. NRT1;2 and NRT2;4B) in roots of both species.

These data indicate that poplar species slow down processes of N acquisition and assimilation in acclimation to limiting N supply.

 

中文摘要（谷歌机翻）

为了研究两种对比的杨树物种的N代谢以适应低氮的可利用性，慢生长物种（Populus popularis，Pp）和快速生长物种（Populus alba×Populus glandulosa，Pg）的幼树暴露于10,100，或1000μMNH₄NO₃。尽管Pp中根系生物量和细根表面积较大，但在Pp中检测到较低的NH₄⁺和NO₃^-净流入量与Pg相比，与Pp根中较低的NH₄⁺和NO₃^-含量以及总氮浓度相当。

同时，与Pg相比，在Pp的根和叶中发现了根中较高的稳定N同位素组成（δ15N）和18个参与N代谢的基因的转录调控的较强响应性。

这些结果表明，Pp的N代谢对降低N的有效性比对Pg更敏感。在这两个物种中，低氮处理减少了NH₄⁺和NO₃^-，根NH₄⁺和叶片NO₃^-含量，根NR活性，根和叶中总N浓度以及大多数铵（AMTs）和硝酸盐（NRTs）的转录水平的净流入量。叶片中的转运蛋白基因和参与根和叶中N同化的基因。低氮可利用性增加了两个物种根中的细根表面积，叶面淀粉浓度，根和叶中的δ15N，以及几种AMT（例如AMT1; 2）和NRT（例如NRT1; 2和NRT2; 4B）的转录物丰度。

这些数据表明，杨树物种在适应限制氮供应的过程中减缓了氮的获取和同化过程。

Net fluxes of NH₄⁺ (A), NO₃^–(B), and H⁺(C) in 10min at 15mm from the root apex of fine roots of P. popularis (Pp) and P. alba × P. glandulosa (Pg). Data indicate mean ± SE (n = 6). The measuring solution (pH 5.5) contained 0.1mM KCl and 0.1mM CaCl2 as well as 10, 100, or 1000 μM NH₄NO₃. Bars labelled with different letters indicate significant difference between the treatments. P-values of the ANOVAs of species, N treatment, and their interaction are indicated. *P < 0.05; **P < 0.01; ***P < 0.001; ****P < 0.0001; ns, not significant (this figure is available in colour at JXB online)

文章链接：https://academic.oup.com/jxb/article/64/14/4207/683851