Rice sodium-insensitive potassium transporter, OsHAK5, confers increased salt tolerance in tobacco BY2 cells

Tomoaki Horie, Mitsuo Sugawara, Tomoyuki Okada, Koichiro Taira, Pulla Kaothien-Nakayama, Maki Katsuhara, Atsuhiko Shinmyo, Hideki Nakayama

Research output: Contribution to journalArticle

51 Citations (Scopus)

Abstract

Potassium ion (K+) plays vital roles in many aspects of cellular homeostasis including competing with sodium ion (Na+) during potassium starvation and salt stress. Therefore, one way to engineer plant cells with improved salt tolerance is to enhance K+ uptake activity of the cells, while keeping Na+ out during salt stress. Here, in search for Na+-insensitive K+ transporter for this purpose, bacterial expression system was used to characterize two K+ transporters, OsHAK2 and OsHAK5, isolated from rice (Oryza sativa cv. Nipponbare). The two OsHAK transporters are members of a KT/HAK/KUP transporter family, which is one of the major K+ transporter families in bacteria, fungi and plants. When expressed in an Escherichia coli K+ transport mutant strain LB2003, both OsHAK transporters rescued the growth defect in K+-limiting conditions by significantly increasing the K+ content of the cells. Under the condition with a large amount of extracellular Na+, we found that OsHAK5 functions as a Na+-insensitive K+ transporter, while OsHAK2 is sensitive to extracellular Na+ and exhibits higher Na+ over K+ transport activities. Moreover, constitutive expression of OsHAK5 in cultured-tobacco BY2 (Nicotiana tabacum cv. Bright Yellow 2) cells enhanced the accumulation of K+ but not Na+ in the cells during salt stress and conferred increased salt tolerance to the cells. Transient expression experiment indicated that OsHAK5 is localized to the plant plasma membrane. These results suggest that the plasma-membrane localized Na+ insensitive K+ transporters, similar to OsHAK5 identified here, could be used as a tool to enhance salt tolerance in plant cells.

Original languageEnglish
Pages (from-to)346-356
Number of pages11
JournalJournal of Bioscience and Bioengineering
Volume111
Issue number3
DOIs
Publication statusPublished - Mar 2011

Fingerprint

Salt-Tolerance
Tobacco
Potassium
Salts
Sodium
Plant Cells
Cell membranes
Cell Membrane
Ions
Starvation
Fungi
Homeostasis
Escherichia coli
Oryza
Bacteria
Cells
Engineers
Growth
Defects

Keywords

  • Escherichia coli
  • Genetic engineering
  • K transport
  • KT/HAK/KUP transporter
  • Na transport
  • Rice
  • Salt tolerance
  • Tobacco
  • Yeast

ASJC Scopus subject areas

  • Biotechnology
  • Applied Microbiology and Biotechnology
  • Bioengineering

Cite this

Rice sodium-insensitive potassium transporter, OsHAK5, confers increased salt tolerance in tobacco BY2 cells. / Horie, Tomoaki; Sugawara, Mitsuo; Okada, Tomoyuki; Taira, Koichiro; Kaothien-Nakayama, Pulla; Katsuhara, Maki; Shinmyo, Atsuhiko; Nakayama, Hideki.

In: Journal of Bioscience and Bioengineering, Vol. 111, No. 3, 03.2011, p. 346-356.

Research output: Contribution to journalArticle

Horie, Tomoaki ; Sugawara, Mitsuo ; Okada, Tomoyuki ; Taira, Koichiro ; Kaothien-Nakayama, Pulla ; Katsuhara, Maki ; Shinmyo, Atsuhiko ; Nakayama, Hideki. / Rice sodium-insensitive potassium transporter, OsHAK5, confers increased salt tolerance in tobacco BY2 cells. In: Journal of Bioscience and Bioengineering. 2011 ; Vol. 111, No. 3. pp. 346-356.
@article{153eb9ffa33b4161926d57c783737300,
title = "Rice sodium-insensitive potassium transporter, OsHAK5, confers increased salt tolerance in tobacco BY2 cells",
abstract = "Potassium ion (K+) plays vital roles in many aspects of cellular homeostasis including competing with sodium ion (Na+) during potassium starvation and salt stress. Therefore, one way to engineer plant cells with improved salt tolerance is to enhance K+ uptake activity of the cells, while keeping Na+ out during salt stress. Here, in search for Na+-insensitive K+ transporter for this purpose, bacterial expression system was used to characterize two K+ transporters, OsHAK2 and OsHAK5, isolated from rice (Oryza sativa cv. Nipponbare). The two OsHAK transporters are members of a KT/HAK/KUP transporter family, which is one of the major K+ transporter families in bacteria, fungi and plants. When expressed in an Escherichia coli K+ transport mutant strain LB2003, both OsHAK transporters rescued the growth defect in K+-limiting conditions by significantly increasing the K+ content of the cells. Under the condition with a large amount of extracellular Na+, we found that OsHAK5 functions as a Na+-insensitive K+ transporter, while OsHAK2 is sensitive to extracellular Na+ and exhibits higher Na+ over K+ transport activities. Moreover, constitutive expression of OsHAK5 in cultured-tobacco BY2 (Nicotiana tabacum cv. Bright Yellow 2) cells enhanced the accumulation of K+ but not Na+ in the cells during salt stress and conferred increased salt tolerance to the cells. Transient expression experiment indicated that OsHAK5 is localized to the plant plasma membrane. These results suggest that the plasma-membrane localized Na+ insensitive K+ transporters, similar to OsHAK5 identified here, could be used as a tool to enhance salt tolerance in plant cells.",
keywords = "Escherichia coli, Genetic engineering, K transport, KT/HAK/KUP transporter, Na transport, Rice, Salt tolerance, Tobacco, Yeast",
author = "Tomoaki Horie and Mitsuo Sugawara and Tomoyuki Okada and Koichiro Taira and Pulla Kaothien-Nakayama and Maki Katsuhara and Atsuhiko Shinmyo and Hideki Nakayama",
year = "2011",
month = "3",
doi = "10.1016/j.jbiosc.2010.10.014",
language = "English",
volume = "111",
pages = "346--356",
journal = "Journal of Bioscience and Bioengineering",
issn = "1389-1723",
publisher = "The Society for Biotechnology, Japan",
number = "3",

}

TY - JOUR

T1 - Rice sodium-insensitive potassium transporter, OsHAK5, confers increased salt tolerance in tobacco BY2 cells

AU - Horie, Tomoaki

AU - Sugawara, Mitsuo

AU - Okada, Tomoyuki

AU - Taira, Koichiro

AU - Kaothien-Nakayama, Pulla

AU - Katsuhara, Maki

AU - Shinmyo, Atsuhiko

AU - Nakayama, Hideki

PY - 2011/3

Y1 - 2011/3

N2 - Potassium ion (K+) plays vital roles in many aspects of cellular homeostasis including competing with sodium ion (Na+) during potassium starvation and salt stress. Therefore, one way to engineer plant cells with improved salt tolerance is to enhance K+ uptake activity of the cells, while keeping Na+ out during salt stress. Here, in search for Na+-insensitive K+ transporter for this purpose, bacterial expression system was used to characterize two K+ transporters, OsHAK2 and OsHAK5, isolated from rice (Oryza sativa cv. Nipponbare). The two OsHAK transporters are members of a KT/HAK/KUP transporter family, which is one of the major K+ transporter families in bacteria, fungi and plants. When expressed in an Escherichia coli K+ transport mutant strain LB2003, both OsHAK transporters rescued the growth defect in K+-limiting conditions by significantly increasing the K+ content of the cells. Under the condition with a large amount of extracellular Na+, we found that OsHAK5 functions as a Na+-insensitive K+ transporter, while OsHAK2 is sensitive to extracellular Na+ and exhibits higher Na+ over K+ transport activities. Moreover, constitutive expression of OsHAK5 in cultured-tobacco BY2 (Nicotiana tabacum cv. Bright Yellow 2) cells enhanced the accumulation of K+ but not Na+ in the cells during salt stress and conferred increased salt tolerance to the cells. Transient expression experiment indicated that OsHAK5 is localized to the plant plasma membrane. These results suggest that the plasma-membrane localized Na+ insensitive K+ transporters, similar to OsHAK5 identified here, could be used as a tool to enhance salt tolerance in plant cells.

AB - Potassium ion (K+) plays vital roles in many aspects of cellular homeostasis including competing with sodium ion (Na+) during potassium starvation and salt stress. Therefore, one way to engineer plant cells with improved salt tolerance is to enhance K+ uptake activity of the cells, while keeping Na+ out during salt stress. Here, in search for Na+-insensitive K+ transporter for this purpose, bacterial expression system was used to characterize two K+ transporters, OsHAK2 and OsHAK5, isolated from rice (Oryza sativa cv. Nipponbare). The two OsHAK transporters are members of a KT/HAK/KUP transporter family, which is one of the major K+ transporter families in bacteria, fungi and plants. When expressed in an Escherichia coli K+ transport mutant strain LB2003, both OsHAK transporters rescued the growth defect in K+-limiting conditions by significantly increasing the K+ content of the cells. Under the condition with a large amount of extracellular Na+, we found that OsHAK5 functions as a Na+-insensitive K+ transporter, while OsHAK2 is sensitive to extracellular Na+ and exhibits higher Na+ over K+ transport activities. Moreover, constitutive expression of OsHAK5 in cultured-tobacco BY2 (Nicotiana tabacum cv. Bright Yellow 2) cells enhanced the accumulation of K+ but not Na+ in the cells during salt stress and conferred increased salt tolerance to the cells. Transient expression experiment indicated that OsHAK5 is localized to the plant plasma membrane. These results suggest that the plasma-membrane localized Na+ insensitive K+ transporters, similar to OsHAK5 identified here, could be used as a tool to enhance salt tolerance in plant cells.

KW - Escherichia coli

KW - Genetic engineering

KW - K transport

KW - KT/HAK/KUP transporter

KW - Na transport

KW - Rice

KW - Salt tolerance

KW - Tobacco

KW - Yeast

UR - http://www.scopus.com/inward/record.url?scp=79951814578&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=79951814578&partnerID=8YFLogxK

U2 - 10.1016/j.jbiosc.2010.10.014

DO - 10.1016/j.jbiosc.2010.10.014

M3 - Article

C2 - 21084222

AN - SCOPUS:79951814578

VL - 111

SP - 346

EP - 356

JO - Journal of Bioscience and Bioengineering

JF - Journal of Bioscience and Bioengineering

SN - 1389-1723

IS - 3

ER -