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Plant Physiology:NRT1.1的信号功能调控植物对铵胁迫的响应

已有 2806 次阅读 2018-10-21 09:41 |个人分类:每日摘要|系统分类:论文交流


NRT1.1-related NH4+ toxicity is associated with a disturbed balance between NH4+ uptake and assimilation


First author: Shaofen Jian; Affiliations: Hunan Agricultural University (湖南农业大学): Changsha, China

Corresponding author: Zhenhua Zhang (张振华)


A high concentration of ammonium (NH4+) as the sole source of nitrogen in the growth medium is often toxic to plants. The nitrate transporter NRT1.1 is involved in mediating the effects of NH4toxicity; however, the mechanism remains undefined. In this study, wild-type Arabidopsis (Arabidopsis thaliana, Col-0) and NRT1.1 mutants (chl1-1 and chl1-5) were grown hydroponically in NH4NOand (NH4)2SOmedia to assess the function of NRT1.1 in NH4stress responses. All the plants grew normally in medium containing mixed N sources, but Col-0 displayed more chlorosis, and lower biomass and photosynthesis than the NRT1.1 mutants in (NH4)2SOmedium. Grafting experiments between Col-0 and chl1-5 further confirmed that NH4toxicity is influenced by NRT1.1. In (NH4)2SOmedium, NRT1.1 induced the expression of NH4transporters, increasing NH4uptake. Additionally, the activities of glutamine synthetase (GS) and glutamate synthetase (GOGAT) in roots of Col-0 plants decreasedandsoluble sugaraccumulated significantly, whereas pyruvate kinase (PK)-mediated glycolysis was not affected, all of which contributed to NH4accumulation. By contrast, the NRT1.1 mutants showed reduced NH4accumulation and enhanced NH4assimilation through GS, GOGAT and GDH. Moreover, the up-regulation of genes involved in ethylene synthesis and senescence in Col-0 plants treated with (NH4)2SOsuggests that ethylene is involved in NH4toxicity responses. The study showed that NH4toxicity is related to a nitrate-independent signaling function of NRT1.1 in Arabidopsis, characterized by enhanced NH4accumulation and altered NH4metabolism, which stimulates ethylene synthesis, leading to plant senescence.




铵态氮(NH4+-N)作为植物利用的一种无机氮源,对植物的生长发育起到重要作用,但是,生长环境中NH4+浓度过高又极易对植物造成毒害作用,抑制植物生长,降低作物产量。在农业生产中,由于过量施肥以及土壤渍害造成的土壤氧化还原电位下降,植物铵毒现象时有发生。日本学者Takushi Hachiya等早在2011年就发现,拟南芥NRT1.1突变体chl1-1chl1-5对高浓度NH4+(10 mM)的耐受性增强,但是对NRT1.1参与调控植物铵毒的作用机制尚不清楚。本研究发现(模式图),在(NH4)2SO4环境下,NRT1.1通过信号调控诱导根中NH4+吸收转运蛋白的表达来增强对生长环境中NH4+的吸收;另外,根系NH4+的同化途径GS/GOGAT循环显著降低,而PK酶活性没有受到显著影响,造成植物体内NH4+大量累积,碳氮代谢失衡,并诱导乙烯的产生,促进植物衰老。nrt1.1突变体根中NH4+吸收转运蛋白没有受到(NH4)2SO4的显著诱导,GS/GOGAT循环也没有受到显著影响,而GDH的活性显著提高,通过对NH4+吸收与同化之间的协同作用,降低了植株体内NH4+的累积,缓解铵毒的发生。



通讯张振华http://zhxy.hunau.edu.cn/jsff/fjs/201606/t20160623_158213.html


个人简介2000-2004年,湖南农业大学,农业资源与环境,学士;2004- 2007年,湖南农业大学,植物营养学,硕士;2007-2010年,湖南农业大学,植物营养学,博士(省优博);2008-2010年,菲律宾国际水稻研究所,博士论文研究(作物营养学),国家留学基金委公派留学基金项目;2013-2016年, 上海植生所,博后。


研究方向:稻油轮作系统粮油作物提质增效机制。



doi: https://doi.org/10.1104/pp.18.00410


Journal: Plant Physiology

First Published: 18 October, 2018


(P.S. 原文下载:链接:https://pan.baidu.com/s/1qFiSsqwlF_7JjmGMbedfhQ  密码:dmu6)




https://blog.sciencenet.cn/blog-3158122-1141984.html

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