SbHKT1;4, a member of the high-affinity potassium transporter gene family from Sorghum bicolor, functions to maintain optimal Na⁺ /K⁺ balance under Na⁺ stress.
SbHKT1;4, a member of the high-affinity potassium transporter gene family from Sorghum bicolor, functions to maintain optimal Na⁺ /K⁺ balance under Na⁺ stress.
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DOI：
10.1111/jipb.12144
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发表时间：
2014-03
影响因子：
11.4
通讯作者：
Tian-tian Wang;Zhijie Ren;Zhi-Quan Liu;Xue Feng;Ruilin Guo;Bao-Guo Li;Leyao Li;Hai-Chun Jing
中科院分区：
文献类型：
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作者：
Tian-tian Wang;Zhijie Ren;Zhi-Quan Liu;Xue Feng;Ruilin Guo;Bao-Guo Li;Leyao Li;Hai-Chun Jing
在盐生植物中，高亲和力钾转运蛋白HKT基因家族在有毒浓度的Na+存在下可以选择性地吸收K+。到目前为止，这还没有得到很好的研究，在glycophytic作物。在这里，我们报告的特性SbHKT 1;4，HKT基因家族的成员，从Sorbiscolor。Na+胁迫时，SbHKT 1; 4的表达在耐盐高粱中上调得更强烈，这与更好的平衡Na +/K+比率和增强的植物生长相关。在酿酒酵母和拟南芥突变体中的异源表达分析表明，过量表达SbHKT 1;4导致对Na+胁迫的超敏反应，并且这种超敏反应可以通过供应高水平的K+来减轻，这暗示SbHKT 1;4可能在过量Na+存在下介导K+吸收。进一步的电生理学证据表明，SbHKT 1;4在非洲爪蟾卵母细胞中表达后可以转运Na+和K+。讨论了SbHKT 1;4在Na+胁迫下维持最佳Na +/K+平衡的功能与耐盐植物育种的相关性。
In halophytic plants, the high-affinity potassium transporter HKT gene family can selectively uptake K⁺ in the presence of toxic concentrations of Na⁺. This has so far not been well examined in glycophytic crops. Here, we report the characterization of SbHKT1;4, a member of the HKT gene family from Sorghum bicolor. Upon Na⁺ stress, SbHKT1;4 expression was more strongly upregulated in salt-tolerant sorghum accession, correlating with a better balanced Na⁺ /K⁺ ratio and enhanced plant growth. Heterogeneous expression analyses in mutants of Saccharomyces cerevisiae and Arabidopsis thaliana indicated that overexpressing SbHKT1;4 resulted in hypersensitivity to Na⁺ stress, and such hypersensitivity could be alleviated with the supply of elevated levels of K⁺, implicating that SbHKT1;4 may mediate K⁺ uptake in the presence of excessive Na⁺. Further electrophysiological evidence demonstrated that SbHKT1;4 could transport Na⁺ and K⁺ when expressed in Xenopus laevis oocytes. The relevance of the finding that SbHKT1;4 functions to maintain optimal Na⁺ /K⁺ balance under Na⁺ stress to the breeding of salt-tolerant glycophytic crops is discussed.