Department of Biotechnology Engineering, ORT Braude College, Snunit 51, P.O. Box 78, Karmiel 2161002, Israel.
International Research Centre for Environmental Membrane Biology, Foshan University, Foshan, China; and Department of Plant Food Products and Biofortification, Institute of Food Biotechnology and Genomics NAS of Ukraine, Kyiv, Ukraine.
Funct Plant Biol. 2023 Jan;50(1):17-28. doi: 10.1071/FP22117.
Plant vacuoles are the main cellular reservoirs to store K+ . The vacuolar K+ channels play a pivotal role in K+ exchange between cytosol and vacuolar sap. Among vacuolar K+ transporters, the Two Pore Potassium Channels (TPKs) are highly selective K+ channels present in most or all plant vacuoles and could be involved in various plant stress responses and developmental processes. Although the majority of TPK members have a vacuolar specialisation, some TPKs display different membrane localisation including the plasma membrane, tonoplast of protein storage vacuoles and probably chloroplast membranes. The functional properties as well as physiological roles of TPKs remains largely unexplored. In this review, we have collected recent data about the physiology, structure, functionality and evolution of TPK/KCO3 channels. We also critically evaluate the latest findings on the biological role, physiological functions, and regulation of TPK/KCO3 channels in relation to their structure and phylogenetic position. The possible role of TPK/KCO3 channels in plant tolerance to various abiotic stresses is summarised, and the future priority directions for TPK/KCO3 studies are addressed.
植物液泡是储存 K+的主要细胞库。液泡中的 K+通道在细胞质和液泡液之间的 K+交换中起着关键作用。在液泡 K+转运体中，双孔钾通道（TPK）是高度选择性的 K+通道，存在于大多数或所有植物液泡中，可能参与各种植物应激反应和发育过程。尽管大多数 TPK 成员具有液泡特化，但一些 TPK 显示出不同的膜定位，包括质膜、蛋白储存液泡的液泡膜和可能的叶绿体膜。TPK 的功能特性和生理作用在很大程度上仍未得到探索。在这篇综述中，我们收集了关于 TPK/KCO3 通道的生理学、结构、功能和进化的最新数据。我们还批判性地评估了关于 TPK/KCO3 通道在与结构和系统发育位置相关的生物学作用、生理功能和调节方面的最新发现。总结了 TPK/KCO3 通道在植物耐受各种非生物胁迫中的可能作用，并提出了 TPK/KCO3 研究的未来优先方向。
