Improvement of phosphorus efficiency in rice on the basis of understanding phosphate signaling and homeostasis

Rice is one of the most important cereal crops feeding a large segment of the world's population. Inefficient utilization of phosphate (Pi) fertilizer by the plant in rice production increases cost and pollution. Developing cultivars with improved Pi use efficiency is essential for the sustainability of agriculture. Pi uptake, translocation and remobilization are regulated by complex molecular mechanisms through the functions of Pi transporters (PTs) and other downstream Pi Starvation Induced (PSI) genes. Expressions of these PSI genes are regulated by the Pi Starvation Response Regulator (OsPHR2)-mediated transcriptional control and/or PHO2-mediated ubiquitination. SPX-domain containing proteins and the type I H+-PPase AVP1 involved in the maintenance and utilization of the internal phosphate. The potential application of posttranscriptional regulation of PT1 through OsPHF1 for Pi efficiency is proposed.