NMT历史上的今天丨Int J Mol Sci 氮营养、Physiol Plantarum 光合文章发表

2018年8月6日，北京林业大学尹伟伦、孟森在International journal of molecular sciences 上发表了标题为Distinct Carbon and Nitrogen Metabolism of Two Contrasting Poplar Species in Response to Different N Supply Levels的文章。

2012年8月6日，中科院海洋所王广策、林阿朋在Physiologia Plantarum上发表了标题为Simultaneous measurements of H+and O2 fluxes in Zostera marina and its physiological implications 的文章。

期刊：International journal of molecular sciences

主题：两种杨树对不同氮素供应水平的碳氮代谢差异

标题：Distinct Carbon and Nitrogen Metabolism of Two Contrasting Poplar Species in Response to Different N Supply Levels

影响因子：3.687

检测指标：NH4+、NO3-、H+流速流速

检测部位：杨树根部

NH4+、NO3-、H+流实验处理方法：

杨树在低中高（0.01,1或10 mM的NH4NO3）的氮浓度下处理4周

NH4+、NO3-、H+流实验测试液成份：

0.01mM/1mM/10mM NH4NO3，0.1mM KCl，0.1mM CaCl 2，pH 5.5

通讯作者：北京林业大学尹伟伦、孟森

英文摘要

Poplars have evolved various strategies to optimize acclimation responses to environmental conditions. However, how poplars balance growth and nitrogen deficiency remains to be elucidated.

In the present study, changes in root development, carbon and nitrogen physiology, and the transcript abundance of associated genes were investigated in slow-growing Populus simonii (Ps) and fast-growing Populus euramericana (Pe) saplings treated with low, medium, and high nitrogen supply. The slow-growing Ps showed a flourishing system, higher δ15N, accelerated C export, lower N uptake and assimilation, and less sensitive transcriptional regulation in response to low N supply.

The slow-growing Ps also had greater resistance to N deficiency due to the transport of photosynthate to the roots and the stimulation of root development, which allows survival. To support its rapid metabolism and growth, compared with the slow-growing Ps, the fast-growing Pe showed greater root development, C/N uptake and assimilation capacity, and more responsive transcriptional regulation with greater N supply. These data suggest that poplars can differentially manage C/N metabolism and photosynthate allocation under different N supply conditions.

杨树已经发展出各种策略来优化对环境条件的适应性反应。然而，杨树如何平衡生长和氮缺乏仍有待阐明。

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在本研究中，在慢生长的小叶杨（Pops simonii）（Ps）和快速生长的欧洲杨（Populus euramericana（Pe）幼树）中研究了根系发育，碳和氮生理学以及相关基因的转录本丰度的变化。高氮供应。缓慢生长的Ps显示出繁殖系统，更高的δ15N，加速的C输出，更低的N吸收和同化，以及响应于低N供应的较不敏感的转录调节。

由于光合产物向根部的转运和根系发育的刺激，缓慢生长的Ps对N缺乏具有更大的抗性，这允许存活。为了支持其快速代谢和生长，与生长缓慢的Ps相比，快速生长的Pe显示出更大的根发育，C / N吸收和同化能力，以及具有更大N供应的更具响应性的转录调节。这些数据表明，杨树可以在不同的氮供应条件下差异化地控制C / N代谢和光合产物分配。

​Figure 4. Net NH4+ (A), NO3− (B) and H+ (C) fluxes of P. simonii (Ps) and Populus euramericana (Pe) under 0.01, 1 and 10 mM 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 < 0.01; *** p < 0.001; ns, not significant.

期刊：Physiologia Plantarum

主题：同时测量H+和O2流速及其生理意义

标题：Simultaneous measurements of H+ and O2 fluxes in Zostera marina and its physiological implications

影响因子：3.067

检测指标：H+、O2流速

检测部位：大叶藻叶片

H+、O2流实验处理方法：

大叶藻叶片瞬时由暗至光（300μmolm-2s-1）处理

H+、O2流实验测试液成份：

天然海水（NSW）盐浓度30–32‰

通讯作者：中科院海洋所王广策、林阿朋

Zostera marina (eelgrass) is an important ecological component of many shallow, temperate lagoons. Evidence suggests that Z. marina has a high bicarbonate utilization capability, which could be promoted by possible proton extrusion and the consequent formation of an ‘acid zone’ in the apoplastic space (unstirred layer) of its leaves.

It has been found that 50 mM of the buffer Tris significantly inhibited the photosynthetic O2 evolution of Z. marina and it was proposed that this was because of Tris's ability to bond with protons outside the cell wall. To investigate if H+ played an important role in the photosynthetic carbon utilization of Z. marina, it is very important to simultaneously monitor the photosynthesis status and possible H+ fluxes. However, probably because of the lack of suitable techniques, this has never been attempted.

In this study, experiments were undertaken on Z. marina by monitoring H+ and O2 fluxes and the relative electron transport rates during light–dark transition. During stable photosynthesis, in addition to an obvious O2 outflow, there was a significant net H+ influx connected to Z. marina photosynthesis. The inhibitory effects of both Tris and respiration inhibitors on apparent O2 evolution of Z. marina were confirmed. However, evidence did not support the proposed Tris inhibition mechanism.

Zostera marina（eelgrass）是许多浅水温带泻湖的重要生态组成部分。有证据表明，Z。marina具有较高的碳酸氢盐利用能力，可以通过可能的质子挤出促进，并因此在其叶片的非质外体空间（未搅拌层）中形成“酸性区域”。

已经发现50mM的缓冲液Tris显着抑制了Z.marina的光合作用O2进化，并且提出这是因为Tris能够与细胞壁外的质子结合。为了研究H +是否在Z. marina的光合碳利用中起重要作用，同时监测光合作用状态和可能的H +通量是非常重要的。然而，可能由于缺乏合适的技术，这从未尝试过。

在这项研究中，通过监测H +和O2通量以及在明暗过渡期间的相对电子传输速率对Z.marina进行了实验。在稳定的光合作用期间，除了明显的O2流出外，还有显着的净H +流入与Z. marina光合作用相关。证实了Tris和呼吸抑制剂对Z. marina的表观O2进化的抑制作用。然而，证据不支持所提出的Tris抑制机制。

Fig. 1. Typical transient changes in H+ flux near Zostera marina leaf segments in response to bright white light. The result of a single measurement is used in this figure as multiple results in one graph would result in large fluctuations and mask the transient responses. The sample was dark adapted for >1 h. After 25 min of measurement, leaf segments were exposed to bright white light (300 μmol m−2 s−1)for 15 min. Measurements were made at intervals of 6.4 s. Each point on the graph represents average data over an interval of three measurements.