Current pressure on agricultural crop production is high. Besides climate change reducing the optimal areal, the European Green Deal demands sustainable crop solutions with strict reductions of fertilizer input (20 to 50%). However, locally available fertilizers and nutrients determine the plant’s development and hence the crop’s yield, so the EU measures risk to directly affect crop production. Among the plant nutrients, phosphorus (P), acquired in form of inorganic phosphate (Pi), represents an essential one. Both the problem of bioavailability of Pi in soils and its limited mineral mining resources, demand for the development of plants that perform better in conditions with reduced Pi-input or -availability. In Pi-deficient conditions, plants deploy local and systemic signalling to increase Pi-uptake and adjust their development. However, the known transcription-dependent response is rather long-term and the actual signals triggering or priming the necessary gene expression changes are less understood. In this project we aim to better understand the early processes and signals induced by Pi-deficiency. The goal would be to use these insights in Pi-dependent signalling to improve the efficiency of Pi-uptake, -distribution and -usage, but also to optimize the plant’s architecture. To determine the early triggers or switches of this developmental response, we will design an innovative real-time observation platform combining advanced microscopy and microfluidics. Observations made using this platform will then be investigated in an extensive ‘omics’ approach, thereby focusing on fast responses, such as protein modifications. This combined approach will guide us to unravel the early physiological, molecular, and biochemical Pi-signalling responses. Following validation in the model species Arabidopsis thaliana, the knowledge gained might inspire to modify crop species, such as tomato, to overcome Pi-deficient conditions.