Unknown

Dataset Information

0

The Rice High-Affinity K+ Transporter OsHKT2;4 Mediates Mg2+ Homeostasis under High-Mg2+ Conditions in Transgenic Arabidopsis.


ABSTRACT: Rice (Oryza sativa; background Nipponbare) contains nine HKT (high-affinity K+ transport)-like genes encoding membrane proteins belonging to the superfamily of Ktr/TRK/HKT. OsHKTs have been proposed to include four selectivity filter-pore-forming domains homologous to the bacterial K+ channel KcsA, and are separated into OsHKT1s with Na+-selective activity and OsHKT2s with Na+-K+ symport activity. As a member of the OsHKT2 subfamily, OsHKT2;4 renders Mg2+ and Ca2+ permeability for yeast cells and Xenopus laevis oocytes, besides K+ and Na+. However, physiological functions related to Mg2+in planta have not yet been identified. Here we report that OsHKT2;4 from rice (O. sativa; background Nipponbare) functions as a low-affinity Mg2+ transporter to mediate Mg2+ homeostasis in plants under high-Mg2+ environments. Using the functional complementation assay in Mg2+-uptake deficient Salmonella typhimurium strains MM281 and electrophysiological analysis in X. laevis oocytes, we found that OsHKT2;4 could rescue the growth of MM281 in Mg2+-deficient conditions and induced the Mg2+ currents in oocytes at millimolar range of Mg2+. Additionally, overexpression of OsHKT2;4 to Arabidopsis mutant lines with a knockout of AtMGT6, a gene encoding the transporter protein necessary for Mg2+ adaptation in Arabidopsis, caused the Mg2+ toxicity to the leaves under the high-Mg2+ stress, but not under low-Mg2+ environments. Moreover, this Mg2+ toxicity symptom resulted from the excessive Mg2+ translocation from roots to shoots, and was relieved by the increase in supplemental Ca2+. Together, our results demonstrated that OsHKT2;4 is a low-affinity Mg2+ transporter responsible for Mg2+ transport to aerials in plants under high-Mg2+ conditions.

SUBMITTER: Zhang C 

PROVIDER: S-EPMC5660728 | biostudies-literature | 2017

REPOSITORIES: biostudies-literature

altmetric image

Publications

The Rice High-Affinity K<sup>+</sup> Transporter OsHKT2;4 Mediates Mg<sup>2+</sup> Homeostasis under High-Mg<sup>2+</sup> Conditions in Transgenic <i>Arabidopsis</i>.

Zhang Chi C   Li Hejuan H   Wang Jiayuan J   Zhang Bin B   Wang Wei W   Lin Hongxuan H   Luan Sheng S   Gao Jiping J   Lan Wenzhi W  

Frontiers in plant science 20171024


Rice (<i>Oryza sativa</i>; background Nipponbare) contains nine <i>HKT</i> (high-affinity K<sup>+</sup> transport)-like genes encoding membrane proteins belonging to the superfamily of Ktr/TRK/HKT. OsHKTs have been proposed to include four selectivity filter-pore-forming domains homologous to the bacterial K<sup>+</sup> channel KcsA, and are separated into OsHKT1s with Na<sup>+</sup>-selective activity and OsHKT2s with Na<sup>+</sup>-K<sup>+</sup> symport activity. As a member of the OsHKT2 subf  ...[more]

Similar Datasets

2015-09-09 | PXD002075 | Pride
2020-02-04 | GSE143857 | GEO
| S-EPMC7390907 | biostudies-literature
| S-EPMC6435114 | biostudies-literature
| S-EPMC4809294 | biostudies-literature
| S-EPMC3009663 | biostudies-literature
| S-EPMC21291 | biostudies-literature
| S-EPMC3048100 | biostudies-literature
| S-EPMC2872450 | biostudies-literature
| S-EPMC7473646 | biostudies-literature