College of Agronomy, Northeast Agricultural University, Harbin, China; Key Laboratory of Soybean Biology in Chinese Education Ministry (Northeastern Key Laboratory of Soybean Biology and Genetics and Breeding in Chinese Ministry of Agriculture), Northeast Agricultural University, Harbin, China.
College of Agronomy, Northeast Agricultural University, Harbin, China; Key Laboratory of Soybean Biology in Chinese Education Ministry (Northeastern Key Laboratory of Soybean Biology and Genetics and Breeding in Chinese Ministry of Agriculture), Northeast Agricultural University, Harbin, China.
Plant Sci. 2021 Mar;304:110736. doi: 10.1016/j.plantsci.2020.110736. Epub 2020 Nov 4.
Plant roots absorb K from soil via K channels and transporters, which are important for stress responses. In this research, GmAKT1, an AKT1-type K channel, was isolated and characterized. The expression of GmAKT1 was induced by K-starvation and salinity stresses, and it was preferentially expressed in the soybean roots. And GmAKT1 was located in the plasma membrane. As an inward K channel, GmAKT1 participated in K uptake, as well as rescued the low-K-sensitive phenotype of the yeast mutant and Arabidopsis akt1 mutant. Overexpression of GmAKT1 significantly improved the growth of plants and increased K concentration, leading to lower Na/K ratios in transgenic Arabidopsis and chimeric soybean plants with transgenic hairy roots. In addition, GmAKT1 overexpression resulted in significant upregulation of these ion uptake-related genes, including GmSKOR, GmsSOS1, GmHKT1, and GmNHX1. Our findings suggested that GmAKT1 plays an important part in K uptake under low-K condition, and could maintain Na/K homeostasis under salt stress in Arabidopsis and soybean plants.
植物根系通过钾通道和转运蛋白从土壤中吸收钾，这些对于应对胁迫反应非常重要。本研究分离并鉴定了一种 AKT1 型钾通道 GmAKT1。GmAKT1 的表达受低钾和盐胁迫诱导，且在大豆根中优先表达。GmAKT1 位于质膜上。作为内向钾通道，GmAKT1 参与钾的摄取，并挽救了酵母突变体和拟南芥 akt1 突变体的低钾敏感表型。过表达 GmAKT1 可显著改善植物生长，增加钾浓度，从而降低转基因拟南芥和具有转基因毛状根的嵌合体大豆植株中的钠钾比。此外，GmAKT1 的过表达导致这些离子摄取相关基因的显著上调，包括 GmSKOR、GmsSOS1、GmHKT1 和 GmNHX1。研究结果表明，GmAKT1 在低钾条件下的钾吸收中发挥重要作用，并能在拟南芥和大豆植株的盐胁迫下维持钠钾平衡。
