Expression of the AKT1-type K+ channel gene from Puccinellia tenuiflora, PutAKT1, enhances salt tolerance in Arabidopsis
Expression of the AKT1-type K+ channel gene from Puccinellia tenuiflora, PutAKT1, enhances salt tolerance in Arabidopsis
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DOI：
10.1007/s00299-010-0872-2
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发表时间：
2010-08-01
影响因子：
6.2
通讯作者：
Takano, Tetsuo
中科院分区：
文献类型：
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作者：
Ardie, Sintho Wahyuning;Liu, Shenkui;Takano, Tetsuo
钾离子通道在植物中具有重要的生理功能，其中之一就是调节植物对逆境的适应。本研究从耐盐植物星星草（Puccinellia tenuiflora）中克隆了K+通道PutAKT 1 cDNA。系统发育分析表明PutAKT 1属于Shaker钾通道家族中的AKT 1-亚家族。PutAKT 1定位于质膜上，并在根中优先表达。PutAKT 1的表达诱导K+饥饿胁迫在根中，并没有下调过量的Na+的存在。拟南芥植物过表达PutAKT 1表现出增强的耐盐性相比，野生型植物所示的芽表型和干重。PutAKT 1的表达增加了正常、K+饥饿和NaCl胁迫条件下拟南芥的K+含量。表达PutAKT 1的拟南芥也表现出在地上部和根部的Na+积累减少。这些结果表明，PutAKT 1参与介导K+吸收（i）在低亲和力和高亲和力K+吸收范围内，和（ii）不像它在水稻中的同源物，即使在盐胁迫条件下。
Potassium channels are important for many physiological functions in plants, one of which is to regulate plant adaptation to stress conditions. In this study, a K+ channel PutAKT1 cDNA was isolated from the salt-tolerant plant Puccinellia tenuiflora. A phylogenetic analysis showed that PutAKT1 belongs to the AKT1-subfamily in the Shaker K+ channel family. PutAKT1 was localized in the plasma membrane and it was preferentially expressed in the roots. The expression of PutAKT1 was induced by K+-starvation stress in the roots and was not down-regulated by the presence of excess Na+. Arabidopsis plants over-expressing PutAKT1 showed enhanced salt tolerance compared to wild-type plants as shown by their shoot phenotype and dry weight. Expression of PutAKT1 increased the K+ content of Arabidopsis under normal, K+-starvation, and NaCl-stress conditions. Arabidopsis expressing PutAKT1 also showed a decrease in Na+ accumulation both in the shoot and in the root. These results suggest that PutAKT1 is involved in mediating K+ uptake (i) both in low- and in high-affinity K+ uptake range, and (ii) unlike its homologs in rice, even under salt-stress condition.