Homeostasis and Response of Plants to Iron and Phosphorus Deficiency: A Brief Overview and Future Spots

Both iron (Fe) and phosphorus (P) are essential mineral nutrients for all living organisms. In plants, Fe is involved in many key basic redox reactions associated with photosynthesis and respiration and also plays various vital enzymatic reactions such as DNA replication, lipid metabolism, and nitrogen fixation. Although the earth’s crust is full of Fe, the amount of bioavailable Fe is always under the demand for plant growth and development in aerobic soils with neutral to basic pH [1-5]. Such alkaline soils are around 30% of the land worldwide, leading to Fe deficiency is a major constraint in crop productivity [6]. Fe deficiency severely compromises chloroplast development and impair chlorophyll biosynthesis, leading to Fe deficiency induced chlorosis, a robust diagnostic symptom of Fe deficiency. Meanwhile, Fe deficiency is the most serious nutritional disorder affecting more than two billions of people in the word (http://www.who.int/nutrition/ topics/ida/en). Therefore, engineering Fe-rich plants in edible parts will be of great help to counteract malnutrition when plants are the chief nutrient source in the diet. To achieve this goal, we first must understand how plants maintain cellular Fe homeostasis.