NRT1.5/NPF7.3 Functions as a Proton-Coupled H+/K+ Antiporter for K+ Loading into the Xylem in Arabidopsis.
Plant Cell
; 29(8): 2016-2026, 2017 Aug.
Article
em En
| MEDLINE
| ID: mdl-28739644
ABSTRACT
Potassium and nitrogen are essential macronutrients for plant growth and have a positive impact on crop yield. Previous studies have indicated that the absorption and translocation of K+ and NO3- are correlated with each other in plants; however, the molecular mechanism that coordinates K+ and NO3- transport remains unknown. In this study, using a forward genetic approach, we isolated a low-K+-sensitive Arabidopsis thaliana mutant, lks2, that showed a leaf chlorosis phenotype under low-K+ conditions. LKS2 encodes the transporter NRT1.5/NPF7.3, a member of the NRT1/PTR (Nitrate Transporter 1/Peptide Transporter) family. The lks2/nrt1.5 mutants exhibit a remarkable defect in both K+ and NO3- translocation from root to shoot, especially under low-K+ conditions. This study demonstrates that LKS2 (NRT1.5) functions as a proton-coupled H+/K+ antiporter. Proton gradient can promote NRT1.5-mediated K+ release out of root parenchyma cells and facilitate K+ loading into the xylem. This study reveals that NRT1.5 plays a crucial role in K+ translocation from root to shoot and is also involved in the coordination of K+/NO3- distribution in plants.
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Base de dados:
MEDLINE
Assunto principal:
Potássio
/
Prótons
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Arabidopsis
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Proteínas de Transporte de Ânions
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Antiportadores de Potássio-Hidrogênio
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Proteínas de Arabidopsis
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Xilema
Limite:
Animals
Idioma:
En
Ano de publicação:
2017
Tipo de documento:
Article