Advances in the HAK/KUP/KT potassium transporter family in regulating Na+/K+ homeostasis and salt tolerance in plants
Year: 2026
Type: article
Abstract: Soil salinization severely threatens global agricultural sustainability. A key physiological mechanism underpinning plant salt tolerance is the maintenance of Na+/K+ homeostasis. The HAK/KUP/KT family of high-affinity potassium transporters plays a central role in plant responses to both potassium deficiency and salinity stress. This review systematically outlines the classification, evolutionary relationships and functional specialization of this transporter family across diverse plant species. We focus on the multi-layered regulatory network that sustains Na+/K+ balance under salt stress, including calcium signalling transduced through the CBL-CIPK module, transcriptional control by transcription factors and epigenetic modifications, and post-translational regulation via phosphorylation, ubiquitination and dynamic trafficking. Recent functional analyses in crops and woody plants highlight functional diversity and adaptive evolution. Notably, certain transporters from halophytes exhibit specialized roles that, when expressed in glycophytes, can paradoxically reduce salt tolerance, underscoring species-specific functional divergence. As a central hub integrating potassium nutrition and stress signalling, the HAK/KUP/KT family represents a promising target for genetic improvement. Future strategies employing gene editing, synthetic promoters and synthetic biology hold promise for developing salt-tolerant, high-yielding crop varieties.
Source: Annals of Botany
DOI: 10.1093/aob/mcag193
Institution: Yunnan Agricultural University
Language: English
Subfield: Plant Science
Domain: Life Sciences
SDG: Zero hunger
Open Access status: green
Awards: G1003252579, G6926387817
OpenAlex ID: W7166815183