NMT歷史上的今天丨Front Plant Sci：高銨抑制小麥根部鉀吸收

NMT是基因功能的活體檢測技術，已被103位諾貝爾獎得主所在單位，及北大、清華、中科院使用。

NMT歷史上的今天

2014年12月16日，山東省農科院孔令安用NMT在Frontiers in Plant Science上發表了標題為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

主題：高銨抑制小麥根部鉀吸收

標題：Effects of high NH4+on K+ uptake, culm mechanical strength and grain filling in wheat

影響因子：4.495

檢測指標：K+流速

作者：山東省農科院孔令安

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 ofNH4+ 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 of NH4+. 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（谷歌機翻）

眾所周知，外部NH4+ 的高濃度會抑制植物發育中的許多過程，但其潛在機理仍未得到很好的理解。為了確定高水平的NH4+的負面影響是否與競爭性陽離子攝入相關，將小麥種植在提供適量（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額外的K+（6 g K2O m-2）的情況下進行圖4的測試，以檢查莖稈機械強度，維管束的主要成分，氮（N）遷移和谷粒填充率。

結果表明，與中等水平的NH4+相比，過量供應NH4+會顯著降低莖稈機械強度，維管束中纖維素和木質素的含量，氮的固定效率（NRE）和籽粒填充率。額外提供的K+大大減輕了高NH4+的這些負面影響，導致籽粒灌漿期間莖稈機械強度提高了19.41–26.95％，NRE增加了34.59％。使用掃描離子選擇電極技術（SIET）進行的分析表明，跨膜K +流入的凈速率降低了84.62％，而使用火焰光度法的測量結果表明，在高NH4+的小麥植株中，K+含量降低了36.13％。。

這項研究表明，高NH4+對小麥莖稈機械強度，纖維素和木質素含量，NRE和籽粒充實率的影響可能與抑制小麥吸收K+有關。

(B) The effects of 10 mM NH4+ on the kinetics of the net K+ ?uxes in wheat root epidermal cells; each point is the mean from six individual plants. (C) Each column presents
the mean values of the K+ ?uxes 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 signi?cant differences at the P < 0.05 level.