The inward-rectifying K+ channel SsAKT1 is a candidate involved in K+ uptake in the halophyte Suaeda salsa under saline condition
The inward-rectifying K+ channel SsAKT1 is a candidate involved in K+ uptake in the halophyte Suaeda salsa under saline condition
复制标题
内向整流钾离子通道 SsAKT1 是参与盐碱地碱蓬钾吸收的候选者
DOI：
10.1007/s11104-015-2539-9
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发表时间：
2015-10-01
期刊：
影响因子：
4.9
通讯作者：
Wang, Suo-Min
中科院分区：
文献类型：
--
作者：
Duan, Hui-Rong;Ma, Qing;Wang, Suo-Min
研究背景和目的Shaker AKT 1样通道被认为参与了高亲和力和低亲和力K+的吸收，并与植物的耐盐性相关。盐地碱蓬（Suaeda maritima subsp. salsa）是一种典型的盐生植物，在盐胁迫下能有效吸收K+，并能吸收大量的Na+，从而维持细胞内K+浓度。本研究探讨了盐生植物S.方法利用SsAKT 1基因对盐地碱蓬（S.结果SsAKT 1由879个氨基酸残基组成，与其他植物的内向整流钾通道AKT 1同源性较高（60- 67%）。SsAKT 1的表达挽救了酵母菌株CY 162的K+摄取缺陷表型，也抑制了酵母菌株G19的盐敏感表型，表明SsAKT 1具有内向整流K+通道的功能。SsAKT 1主要在根中表达，并且被K+饥饿显著诱导;转录物水平在再供应K+（0.1-10 mM，6 h）时进一步增加，在0.1 mM K+中增加62%，在较高K+浓度（1-10 mM）中增加144- 174%。有趣的是，SsAKT 1在根中的表达水平也被短期（6 h）NaCl浓度（25-250 mM）诱导显著。salsa，但在低亲和力系统中发挥更大的作用。此外，SsAKT 1还可能通过参与维持S.盐下的莎莎酱
Background and aimsThe Shaker AKT1-like channels are considered to be involved in both high- and low-affinity K+ uptake and correlated with salt tolerance in glycophytes. Suaeda salsa (Suaeda maritima subsp. salsa), as a typical salt-accumulating halophyte, is able to absorb K+ efficiently while growing under saline conditions and taking in a large amount of Na+, thus maintaining the K+ concentration in its cells. In this study, the possible functions of the inward-rectifying K+ channel SsAKT1 in K+ uptake and salt tolerance in the halophyte S. salsa were investigated.MethodsSsAKT1 from S. salsa was isolated by RT-PCR and characterized using yeast complementation; the responses of SsAKT1 to various KCl and NaCl treatments were investigated by real-time quantitative PCR.ResultsSsAKT1 consisted of 879 amino acid residues and shared high homology (60–67 %) with the identified inward-rectifying K+ channels AKT1 from other plants. The expression of SsAKT1 rescued the K+-uptake-defective phenotype of yeast strain CY162, and also suppressed the salt-sensitive phenotype of yeast strain G19, suggesting SsAKT1 functioned as an inward-rectifying K+ channel. SsAKT1 was predominantly expressed in roots, and was induced significantly by K+ starvation; transcript levels increased further on resupply of K+ (0.1–10 mM for 6 h) by 62 % in 0.1 mM K+ and 144–174 % in higher K+ concentrations (1–10 mM). Interestingly, the expression level of SsAKT1 in roots was also induced significantly by short-term treatment (6 h) with NaCl concentrations (25–250 mM).ConclusionsThese results demonstrate that the inward-rectifying K+ channel SsAKT1 might mediate both high- and low-affinity K+ uptake in S. salsa, but play a greater role in the low-affinity system. Furthermore, SsAKT1 might also be involved in salt tolerance by participating in the maintenance of K+ nutrition in S. salsa under salinity.