United States Department of Agriculture/Agricultural Research Service Children's Nutrition Research Center, Baylor College of Medicine, Houston, TX 77030, USA
Plant Biol (Stuttg). 2011 Jul;13(4):561-9. doi: 10.1111/j.1438-8677.2011.00466.x. Epub 2011 May 12.
Inorganic cations play decisive roles in many cellular and physiological processes and are essential components of plant nutrition. Therefore, the uptake of cations and their redistribution must be precisely controlled. Vacuolar antiporters are important elements in mediating the intracellular sequestration of these cations. These antiporters are energized by the proton gradient across the vacuolar membrane and allow the rapid transport of cations into the vacuole. CAXs (for CAtion eXchanger) are members of a multigene family and appear to predominately reside on vacuoles. Defining CAX regulation and substrate specificity have been aided by utilising yeast as an experimental tool. Studies in plants suggest CAXs regulate apoplastic Ca(2+) levels in order to optimise cell wall expansion, photosynthesis, transpiration and plant productivity. CAX studies provide the basis for making designer transporters that have been used to develop nutrient enhanced crops and plants for remediating toxic soils.
无机阳离子在许多细胞和生理过程中起着决定性的作用，是植物营养的重要组成部分。因此，阳离子的摄取和再分配必须得到精确的控制。液泡反向转运蛋白是介导这些阳离子在细胞内隔离的重要因素。这些反向转运蛋白由液泡膜两侧的质子梯度驱动，允许阳离子快速转运到液泡中。CAX（阳离子交换器）是一个多基因家族的成员，似乎主要存在于液泡中。利用酵母作为实验工具，有助于确定 CAX 的调节和底物特异性。在植物中的研究表明，CAX 调节质外体 Ca(2+)水平，以优化细胞壁扩展、光合作用、蒸腾作用和植物生产力。CAX 的研究为制造设计的转运蛋白提供了基础，这些转运蛋白已被用于开发营养增强作物和植物，以修复有毒土壤。
