Potassium Deficiency and Hormone Signalling in Plants

Potassium (K or K⁺) is a vital macronutrient that influences numerous physiological processes related to plant physiology and development. Recently, there is a growing focus on enhancing K⁺-use efficiency (KUE) to ensure optimal plant growth, especially in K⁺ deficient soils. Most approaches are centred on targeting genes associated with K⁺ sensing, signalling and other pathways related to plant hormones. However, despite progress, the success stories for generating high KUE crops are still limited. In view of this, the present review highlights the role of hormonal signalling in regulating K⁺ deficiency-induced responses in plants. We integrate shreds of evidence of how these K⁺-hormone signalling crosstalk modulate root-system architecture, K⁺ uptake and stress resilience. Furthermore, a meta-analysis-based assessment of different hormones highlighted the central role of jasmonic acid and abscisic acid in mediating K⁺ deficiency-induced changes at the transcriptional level. The present review offers novel insights into K⁺-hormone crosstalk that can be used as a framework for advancing KUE research and addressing challenges towards global food security.