Han Wu, Ji Yun, Wu Wei, Cheng Jin-Kui, Feng Han-Qian, Wang Yi
State Key Laboratory of Plant Physiology and Biochemistry (SKLPPB), College of Biological Sciences, China Agricultural University, Beijing, China.
State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou, China.
Front Plant Sci. 2021 Mar 3;12:517742. doi: 10.3389/fpls.2021.517742. eCollection 2021.
Potassium (K) is one of essential mineral elements for plant growth and development. K channels, especially AKT1-like channels, play crucial roles in K uptake in plant roots. Maize is one of important crops; however, the K uptake mechanism in maize is little known. Here, we report the physiological functions of K channel ZMK1 in K uptake and homeostasis in maize. is a homolog of channel in maize, and mainly expressed in maize root. Yeast complementation experiments and electrophysiological characterization in oocytes indicated that ZMK1 could mediate K uptake. rescued the low-K-sensitive phenotype of mutant and enhanced K uptake in . Overexpression of also significantly increased K uptake activity in maize, but led to an oversensitive phenotype. Similar to AKT1 regulation, the protein kinase ZmCIPK23 interacted with ZMK1 and phosphorylated the cytosolic region of ZMK1, activating ZMK1-mediated K uptake. could also complement the low-K-sensitive phenotype of / mutant. These findings demonstrate that ZMK1 together with ZmCIPK23 plays important roles in K uptake and homeostasis in maize.
钾（K）是植物生长发育所必需的矿质元素之一。钾通道，尤其是类AKT1通道，在植物根系吸收钾的过程中发挥着关键作用。玉米是重要的农作物之一；然而，玉米的钾吸收机制却鲜为人知。在此，我们报道了钾通道ZMK1在玉米钾吸收和体内平衡中的生理功能。ZMK1是玉米中 通道的同源物，主要在玉米根中表达。酵母互补实验和卵母细胞电生理特性表明，ZMK1能够介导钾的吸收。ZMK1拯救了 突变体的低钾敏感表型，并增强了 中的钾吸收。ZMK1的过表达也显著提高了玉米的钾吸收活性，但导致了过度敏感的表型。与AKT1调控相似，蛋白激酶ZmCIPK23与ZMK1相互作用，并使ZMK1的胞质区域磷酸化，激活ZMK1介导的钾吸收。ZMK1也能拯救 / 突变体的低钾敏感表型。这些发现表明，ZMK1与ZmCIPK23一起在玉米的钾吸收和体内平衡中发挥重要作用。 （注：原文中部分内容缺失具体信息，用 表示）
