The transport of essential micronutrients in rice

Micronutrients such as iron (Fe), copper (Cu), manganese (Mn), and zinc (Zn) are integral to living organisms for normal growth and reproduction. In plants, these minerals are involved in various cellular and molecular processes, such as chlorophyll synthesis and photosynthesis (Cu, Fe, and Mn), respiration (Cu and Fe), and stabilization of DNA and gene expression (Zn). A deficiency or an excess of these minerals severely impairs plant growth and development. When soil pH is high, these elements are often present as oxidized compounds, making their uptake extremely difficult. Plants utilize complex mechanisms to acquire these minerals from the rhizosphere, transport them from roots to shoots, and deliver them to developing tissues and edible parts of the plants. Uptake of these metals is extremely complex and tightly regulated. Cadmium, which is toxic for all living organisms, significantly interferes with the uptake of these metals. Here, we review recent developments in understanding metal transport in plants with a particular focus on rice and discuss strategies for breeding crop plants suitable for a diverse range of soils and climates, which will contribute to the production of healthier food for human consumption.