NMT历史上的今天丨Front Plant Sci：高铵抑制小麦根部钾吸收

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NMT历史上的今天

2014年12月16日，山东省农科院孔令安用NMT在Frontiers in Plant Science上发表了标题为Effects of high NH4+ on K+ uptake, culm mechanical strength and grain filling in wheat的研究成果。

 

• 期刊：Frontiers in Plant Science
• 主题：高铵抑制小麦根部钾吸收
• 标题：Effects of high NH4+on K+ uptake, culm mechanical strength and grain filling in wheat
• 影响因子：4.495
• 检测指标：K+流速
• 通讯作者：山东省农科院孔令安

英文摘要

It is well established that a high external NH₄⁺ concentration depresses many processes in plant development, but the underlying mechanisms are still not well understood. To determine whether the negative effects of high levels of NH4+ are related to competitive cation uptake, wheat was grown in a field with moderate (18 g N m−2) and high (30 g N m−2) supplies o fNH₄⁺ in the presence or absence of additional K+ (6 g K2O m−2) to examine culm mechanical strength, the main components of the vascular bundle, nitrogen (N) remobilization and the grain-filling rate.

The results indicated that an excessive supply of NH₄⁺ significantly decreased culm mechanical strength, the cellulose and lignin contents of vascular bundles, the N remobilization efficiency (NRE) and the grain-filling rate compared with a moderate level ofNH₄⁺. The additional provision of K⁺ considerably alleviated these negative effects of high NH₄⁺, resulting in a 19.41–26.95% increase in culm mechanical strength during grain filling and a 34.59% increase in the NRE. An assay using the scanning ion-selective electrode technique (SIET) showed that the net rate of transmembrane K+ influx decreased by 84.62%, and measurements using flame photometry demonstrated that the K⁺ content decreased by 36.13% in wheat plants subjected to high NH₄⁺.

This study indicates that the effects of high NH₄⁺ on culm mechanical strength, cellulose and lignin contents, the NRE and the grain-filling rate are probably associated with inhibition of K+ uptake in wheat.

中文摘要（谷歌机翻）

众所周知，外部NH4+ 的高浓度会抑制植物发育中的许多过程，但其潜在机理仍未得到很好的理解。为了确定高水平的NH4+的负面影响是否与竞争性阳离子摄入相关，将小麦种植在提供适量（18 g N m-2）和大量（30 g N m-2）NH4+的田地上在存在或不存在额外的K+（6 g K2O m-2）的情况下进行图4的测试，以检查茎秆机械强度，维管束的主要成分，氮（N）迁移和谷粒填充率。

结果表明，与中等水平的NH₄⁺相比，过量供应NH₄⁺+会显着降低茎秆机械强度，维管束中纤维素和木质素的含量，氮的固定效率（NRE）和籽粒填充率。额外提供的K⁺大大减轻了高NH₄⁺的这些负面影响，导致籽粒灌浆期间茎秆机械强度提高了19.41–26.95％，NRE增加了34.59％。使用扫描离子选择电极技术（SIET）进行的分析表明，跨膜K⁺流入的净速率降低了84.62％，而使用火焰光度法的测量结果表明，在高NH₄⁺的小麦植株中，K⁺含量降低了36.13％。

这项研究表明，高NH₄⁺对小麦茎秆机械强度，纤维素和木质素含量，NRE和籽粒充实率的影响可能与抑制小麦吸收K+有关。

(B) The effects of 10 mM NH₄⁺ on the kinetics of the net K⁺ fluxes in wheat root epidermal cells; each point is the mean from six individual plants. (C) Each column presents the mean values of the K⁺ fluxes measured in the root epidermal cells over a recording period of 30 min. Nm: moderate NH₄⁺,Nh:10mM NH₄⁺ treatment. The bars represent the standard deviation for six individual plants. The different letters indicated above each column refer to significant differences at the P < 0.05 level.

文章链接：https://www.frontiersin.org/articles/10.3389/fpls.2014.00703/full