Abstract
Zinc (Zn) is an essential micronutrient involved in numerous physiological processes in plants, serving catalytic, structural, and regulatory functions. Maintaining its appropriate concentration requires precise control of uptake, transport, distribution, and storage, as both Zn deficiency and excess lead to disruptions in plant growth and development. This paper presents the mechanisms regulating zinc homeostasis in plants, with a particular focus on the role of membrane transporters and chelating compounds. The ZIP, MTP, and HMA protein families play a key role, being responsible for cellular Zn uptake, its sequestration within organelles, and inter-tissue transport, respectively. Low-molecular-weight chelating ligands maintain safe zinc levels in the cytosol, and some of them facilitate its storage in vacuoles. Furthermore, they enhance its symplastic mobility and enable zinc transport in the xylem and phloem, thereby facilitating its distribution to shoots and seeds. Overall, this demonstrates the complex and multilevel nature of zinc homeostasis regulation in plants