Micronutrients are essential for plant survival despite the low amount needed in comparison to macronutrients. The dynamic range of optimal internal concentrations for micronutrients is thus particularly narrow, and this requires a tight regulation so that its requirements are met under different developmental and environmental conditions. There has been much progress in identifying regulators of the micronutrient metal homeostasis network in plants. These regulators control the expression of genes involved in metal acquisition, mobilization, and storage in response to variations in metal availability, particularly in response to deficiency. Here we present a brief overview on the mechanisms of regulation of iron, copper, and zinc homeostasis and deficiency responses in model plant species. Advances in this area, followed by translational approaches into crops, will likely provide new avenues for breeding crops with improved micronutrient use efficiency and nutritional value.