Guangjie Li , Zhaoyue Wang , Lin Zhang , Herbert J. Kronzucker , Gui Chen , Yanqin Wang , Weiming Shi , Yan Li
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引用次数: 0
Abstract
Ammonium (NH4+) is toxic to root growth in most plants, and NH4+ toxicity has been linked to disruptions in plant Fe homeostasis. However, only a few genes have been linked to the disruption of Fe homeostasis under NH4+ nutrition, and pathway details have as yet to be resolved. Here, using RNA-seq analysis and RT-qPCR, we explore the response of different genes expressed in the roots of Fe-replete and Fe-starved Arabidopsis plants under NH4+ conditions. The Nitrate Transporter 1.1 (NRT1.1) gene, known to code for a dual-affinity nitrate transporter, but not other NRTs genes, was specifically induced in Fe-replete plants in response to NH4+ provision. NRT1.1 antagonizes NH4+-dependent Fe accumulation, and this antagonism requires NO3- supply. Constitutively expressing NRT1.1 confers higher NO3- uptake and reduces NH4+-dependent Fe accumulation by increasing pH in the rhizosphere. Building on previous evidence establishing the involvement of root Fe accumulation in the root growth response to elevated NH4+, our study shows that NRT1.1-mediated nitrate uptake curtails symptoms of NH4+ toxicity under elevated NH4+ and in the presence of NO3-, by increasing rhizospheric pH, offering new insights into possible pathways for improving the tolerance to NH4+ toxicity in plants.
期刊介绍:
Environmental and Experimental Botany (EEB) publishes research papers on the physical, chemical, biological, molecular mechanisms and processes involved in the responses of plants to their environment.
In addition to research papers, the journal includes review articles. Submission is in agreement with the Editors-in-Chief.
The Journal also publishes special issues which are built by invited guest editors and are related to the main themes of EEB.
The areas covered by the Journal include:
(1) Responses of plants to heavy metals and pollutants
(2) Plant/water interactions (salinity, drought, flooding)
(3) Responses of plants to radiations ranging from UV-B to infrared
(4) Plant/atmosphere relations (ozone, CO2 , temperature)
(5) Global change impacts on plant ecophysiology
(6) Biotic interactions involving environmental factors.