Root zone-specific localization of AMTs determines ammonium transport pathways and nitrogen allocation to shoots.

Details

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State: Public
Version: Final published version
Serval ID
serval:BIB_304216FEFC20
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Root zone-specific localization of AMTs determines ammonium transport pathways and nitrogen allocation to shoots.
Journal
PLoS biology
Author(s)
Duan F., Giehl RFH, Geldner N., Salt D.E., von Wirén N.
ISSN
1545-7885 (Electronic)
ISSN-L
1544-9173
Publication state
Published
Issued date
10/2018
Peer-reviewed
Oui
Volume
16
Number
10
Pages
e2006024
Language
english
Notes
Publication types: Journal Article ; Research Support, U.S. Gov't, Non-P.H.S.
Publication Status: epublish
Abstract
In plants, nutrient provision of shoots depends on the uptake and transport of nutrients across the root tissue to the vascular system. Nutrient delivery to the vasculature is mediated via the apoplastic transport pathway (ATP), which uses the free space in the cell walls and is controlled by apoplastic barriers and nutrient transporters at the endodermis, or via the symplastic transport pathway (STP). However, the relative importance of these transport routes remains elusive. Here, we show that the STP, mediated by the epidermal ammonium transporter 1;3 (AMT1;3), dominates the radial movement of ammonium across the root tissue when external ammonium is low, whereas apoplastic transport controlled by AMT1;2 at the endodermis prevails at high external ammonium. Then, AMT1;2 favors nitrogen (N) allocation to the shoot, revealing a major importance of the ATP for nutrient partitioning to shoots. When an endodermal bypass was introduced by abolishing Casparian strip (CS) formation, apoplastic ammonium transport decreased. By contrast, symplastic transport was increased, indicating synergism between the STP and the endodermal bypass. We further establish that the formation of apoplastic barriers alters the cell type-specific localization of AMTs and determines STP and ATP contributions. These results show how radial transport pathways vary along the longitudinal gradient of the root axis and contribute to nutrient partitioning between roots and shoots.
Keywords
Ammonium Compounds/metabolism, Arabidopsis/physiology, Arabidopsis Proteins/physiology, Biological Transport/physiology, Cation Transport Proteins/metabolism, Cation Transport Proteins/physiology, Cell Wall, Gene Expression Regulation, Plant/genetics, Ion Transport/physiology, Membrane Transport Proteins/physiology, Nitrogen/metabolism, Plant Proteins/metabolism, Plant Proteins/physiology, Plant Roots/metabolism, Plant Roots/physiology
Pubmed
Web of science
Open Access
Yes
Create date
10/12/2018 14:19
Last modification date
20/08/2019 13:15
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