Are we ready to improve phosphorus homeostasis in rice?

Phosphorus (P) is an essential macronutrient which often limits plant growth, but the phosphate rock used for fertilizer production is a finite resource. On the other hand, large amounts of P compounds are entering surface waters, leading to eutrophication. Therefore, improvement of phosphate use efficiency of crop plants is a major task for plant science. Rice as a staple crop has recently been a focus of such efforts with several major discoveries. New transporters controlling phosphate homeostasis in rice have been discovered. Manipulation of expression of the corresponding genes improves different components of phosphate use efficiency, such as delivery of phosphate to the developing seeds and synthesis of phytic acid. Here these new findings are discussed in the context of general P nutrition and with the aim of finding out how far we can optimize P homeostasis in rice