Rice OsHKT2;1 transporter mediates large Na+ influx component into K+-starved roots for growth
SCIE
SCOPUS
- Title
- Rice OsHKT2;1 transporter mediates large Na+ influx component into K+-starved roots for growth
- Authors
- Horie, T; Costa, A; Kim, TH; Han, MJ; Horie, R; Leung, HY; Miyao, A; Hirochika, H; An, G; Schroeder, JI
- Date Issued
- 2007-06-20
- Publisher
- NATURE PUBLISHING GROUP
- 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 wildtype 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. Na-22(+) 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 30mM 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.
- Keywords
- hKT; Na+ uptake; salt stress; ALKALI CATION TRANSPORT; SALT TOLERANCE; ARABIDOPSIS-THALIANA; HKT TRANSPORTERS; HIGH-AFFINITY; SODIUM UPTAKE; TOS17 RETROTRANSPOSON; GLYCINE RESIDUES; POTASSIUM UPTAKE; HIGHER-PLANTS
- URI
- https://oasis.postech.ac.kr/handle/2014.oak/23294
- DOI
- 10.1038/SJ.EMBOJ.760
- ISSN
- 0261-4189
- Article Type
- Article
- Citation
- EMBO JOURNAL, vol. 26, no. 12, page. 3003 - 3014, 2007-06-20
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