NRT1.5/NPF7.3 Functions as a Proton-Coupled H + /K + Antiporter for K + Loading into the Xylem in Arabidopsis.

Autor: Li H; State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China., Yu M; State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China., Du XQ; State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China., Wang ZF; State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China., Wu WH; State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China., Quintero FJ; Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas, 41092 Sevilla, Spain., Jin XH; State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China., Li HD; State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China., Wang Y; State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China yiwang@cau.edu.cn.
Jazyk: angličtina
Zdroj: The Plant cell [Plant Cell] 2017 Aug; Vol. 29 (8), pp. 2016-2026. Date of Electronic Publication: 2017 Jul 24.
DOI: 10.1105/tpc.16.00972
Abstrakt: 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 NO 3 - are correlated with each other in plants; however, the molecular mechanism that coordinates K + and NO 3 - 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 NO 3 - 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 + /NO 3 - distribution in plants.
(© 2017 American Society of Plant Biologists. All rights reserved.)
Databáze: MEDLINE
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