The uptake of mineral nutrients by plants depends on the dissociation of ions in the soil solution and movement to the root surface. Therefore, suffi cient soil water is critical for adequate plant nutrition. Although in many regions crops are grown under water - limited conditions and drought frequently causes yield losses, nutrient uptake usually keeps pace with the dry matter, which stabilizes the mineral nutrient concentrations in plant tissues. However, there are conditions when this homeostasis is disturbed. These situations provide insight into the regulation of nutrient balance and the role of nutrients in maintaining plant function, particularly under stress. There are new and exciting developments in the area of root - to - shoot communication involving nitrate, regulation of hydraulic conductivity, and stomatal function via abscisic acid (ABA) and K + , and genetic control of root system architecture. Further examination of how nutrient concentrations, growth, and water use are governed and regulated at the molecular level may provide avenues for further crop improvement.