Technical Abstract: Plants have developed a number of transport mechanisms to control the acquisition, partitioning and deposition of the micronutrients, iron, copper, zinc and manganese. This control is important because the plant must obtain adequate levels of these essential nutrients for both vegetative and reproductive tissues, while at the same time preventing excess accumulation. Points of physiological control include various root system processes, movement and partitioning along the xylem pathway, temporary storage in vegetative compartments, and remobilization via the phloem pathway. The regulation of these control points is not fully understood, although it appears that certain functions may be influenced by inter-organ communication. Current evidence does indicate that these processes can be controlled to various degrees; differences exist not only between species, they can also vary temporally and spatially within a given nplant. Because this regulatory variability exists, it would appear that enhancing the micronutrient density of edible plant components through the manipulation of physiological processes is an achievable goal.