Phosphate (P) limitation is a widespread abiotic stress, profoundly impacting crop yield. Breeding low P-tolerant crops is therefore a priority request for world agriculture. One outspoken effect of P deficiency is the loss of the root stem cells, resulting in meristem exhaustion. Recently, the host lab demonstrated that the DNA damage response (DDR) regulators CASEIN KINASE 2 (CK2) and SUPPRESSOR OF GAMMA RADIATION1 (SOG1) control the loss of these stem cells, linking for the first time the DDR pathway with the physiological problem of P limitation. However, at the molecular level it is still unclear how CK2 and SOG1 participate in this process. This fundamental research project aims at addressing this knowledge gap through (1) mapping the tissue-specific roles of CK2 in response to P deficiency, (2) mapping the complete CK2 substrate spectrum under P limiting conditions, and (3) dissecting the pathway downstream of SOG1 being responsible for the meristem exhaustion phenotype. In an applied part of the project, findings are transferred to maize, focusing on in soil phenotyping under P-rich versus P-poor growth conditions. Therefore, the results obtained from this research project might not only contribute to a deeper understanding of the DDR mechanisms regulating plant growth under P starvation, but might also open new avenues to cope with the problem of P limitation.