Decoding Long-Distance Communication Under Mineral Stress: Advances in Vascular Signalling and Molecular Tools for Plant Resilience.

Mineral nutrients are essential for plant growth, development and crop yield. Under mineral deficient conditions, plants rely on a sophisticated network of signalling pathways to coordinate their molecular, physiological, and morphological responses. Recent research has shown that long-distance signalling pathways play a pivotal role in maintaining mineral homeostasis and optimising growth. This review explores the intricate mechanisms of long-distance signalling under mineral deficiencies, emphasising its importance as a communication network between roots and shoots. Through the vascular tissues, plants transport an array of signalling molecules, including phytohormones, small RNAs, proteins, small peptides, and mobile mRNAs, to mediate systemic responses. Vascular tissues, particularly companion cells, are critical hubs for sensing and relaying mineral deficiency signals, leading to rapid changes in mineral uptake and optimised root morphology. We highlight the roles of key signalling molecules in regulating mineral acquisition and stress adaptation. Advances in molecular tools, including TRAP-Seq, heterografting, and single-cell RNA sequencing, have recently unveiled novel aspects of long-distance signalling and its regulatory components. These insights underscore the essential role of vascular-mediated communication in enabling plants to navigate heterogeneous mineral distribution environments and suggest new avenues for improving crop resilience and mineral use efficiency.