Skip Navigation

Publication Detail

Title: Rice OsHKT2;1 transporter mediates large Na+ influx component into K+-starved roots for growth.

Authors: Horie, Tomoaki; Costa, Alex; Kim, Tae Houn; Han, Min Jung; Horie, Rie; Leung, Ho-Yin; Miyao, Akio; Hirochika, Hirohiko; An, Gynheung; Schroeder, Julian I

Published In EMBO J, (2007 Jun 20)

Abstract: Excessive accumulation of sodium in plants causes toxicity. No mutation that greatly diminishes sodium (Na+) influx into plant roots has been isolated. The OsHKT2;1 (previously named OsHKT1) transporter from rice functions as a relatively Na+-selective transporter in heterologous expression systems, but the in vivo function of OsHKT2;1 remains unknown. Here, we analyzed transposon-insertion rice lines disrupted in OsHKT2;1. Interestingly, three independent oshkt2;1-null alleles exhibited significantly reduced growth compared with wild-type plants under low Na+ and K+ starvation conditions. The mutant alleles accumulated less Na+, but not less K+, in roots and shoots. OsHKT2;1 was mainly expressed in the cortex and endodermis of roots. (22)Na+ tracer influx experiments revealed that Na+ influx into oshkt2;1-null roots was dramatically reduced compared with wild-type plants. A rapid repression of OsHKT2;1-mediated Na+ influx and mRNA reduction were found when wild-type plants were exposed to 30 mM NaCl. These analyses demonstrate that Na+ can enhance growth of rice under K+ starvation conditions, and that OsHKT2;1 is the central transporter for nutritional Na+ uptake into K+-starved rice roots.

PubMed ID: 17541409 Exiting the NIEHS site

MeSH Terms: Cation Transport Proteins/metabolism*; Ion Transport; Oryza/metabolism*; Plant Proteins/metabolism*; Plant Roots/growth & development; Plant Roots/metabolism*; Potassium/metabolism*; Sodium/metabolism*

Back
to Top