Abstract

A great proportion of nitrate taken up by plants is stored in vacuoles. Vacuolar nitrate accumulation and release is of great importance to nitrate reallocation and efficient utilization. However, how plants mediate nitrate efflux from vacuoles to cytoplasm is largely unknown. The current study identified NPF5.11, NPF5.12 and NPF5.16 as vacuolar nitrate efflux transporters in Arabidopsis. Histochemical analysis showed that NPF5.11, NPF5.12 and NPF5.16 were expressed preferentially in root pericycle cells and xylem parenchyma cells, and further analysis showed that these proteins were tonoplast-localized. Functional characterization using cRNA-injected Xenopus laevis oocytes showed that NPF5.11, NPF5.12 and NPF5.16 were low-affinity, pH-dependent nitrate uptake transporters. In npf5.11 npf5.12 npf5.16 triple mutant lines, more root-fed 15NO3− was translocated to shoots compared to the wild type control. In the NPF5.12 overexpression lines, proportionally less nitrate was maintained in roots. These data together suggested that NPF5.11, NPF5.12 and NPF5.16 might function to uptake nitrate from vacuoles into cytosol, thus serving as important players to modulate nitrate allocation between roots and shoots.

Details

Title
Tonoplast-localized nitrate uptake transporters involved in vacuolar nitrate efflux and reallocation in Arabidopsis
Author
Ya-Ni, He 1 ; Jia-Shi, Peng 2 ; Cai, Yao 3 ; De-Fen, Liu 3 ; Guan, Yuan 4 ; Hong-Ying, Yi 2 ; Ji-Ming, Gong 2   VIAFID ORCID Logo 

1  National Key Laboratory of Plant Molecular Genetics and National Center for Plant Gene Research (Shanghai), CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, People’s Republic of China; University of Chinese Academy of Sciences, Beijing, China; Forestry and Fruit Tree Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai, China 
2  National Key Laboratory of Plant Molecular Genetics and National Center for Plant Gene Research (Shanghai), CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, People’s Republic of China 
3  National Key Laboratory of Plant Molecular Genetics and National Center for Plant Gene Research (Shanghai), CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, People’s Republic of China; University of Chinese Academy of Sciences, Beijing, China 
4  National Key Laboratory of Plant Molecular Genetics and National Center for Plant Gene Research (Shanghai), CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, People’s Republic of China; Forestry and Fruit Tree Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai, China 
Pages
1-9
Publication year
2017
Publication date
Jul 2017
Publisher
Nature Publishing Group
e-ISSN
20452322
Source type
Scholarly Journal
Language of publication
English
DOI
https://doi.org/10.1038/s41598-017-06744-5
ProQuest document ID
1956171879
Copyright
© 2017. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.