P-use efficient rice · Inositol pyrophosphates in phosphate homeostasis: increasing nutrition value in rice

Phosphorus (P) is one of the most important molecules having a role in almost every aspect of plant metabolism. So, a constant supply of P and its efficient use as Pi are necessary to sustain plant growth, development and yield. However, in most of the agricultural lands, Pi is poorly available to plants. In order to overcome the consequences of Pi deficiency, farmers have adopted excessive and routine application of P fertilizers, causing serious impacts on the environment. There are two main concerns regarding the excessive use of P fertilizers. On one hand, erosion by water and wind results in P runoff into open water bodies, causing a major threat to planetary health. On the other hand, P deposits represent a limited resource on our planet. Additionally, some P forms within the plant (such as phytate) are crucial to determine micronutrient availability for the human nutrition and animal feed. Therefore, there is an urgent need to understand the functional aspects of Pi sensing, transport, signaling and remobilization, and, thus, it is imperative to develop crops with enhanced PUE (P Use Efficiency) and micronutrient availability to support a more sustainable agriculture system. Although rice counts for the third-most produced cereal crop in the world, it is limited to have only 25% PUE, providing an enormous scope for improvement in P nutrition. In this line, we propose to investigate the synthesis and physiological roles of inositol pyrophosphates (PP-InsPs) in Pi signaling and homeostasis to improve the nutritional value of rice. The proposed research will help to better understand how PP-InsPs control PUE, and will provide the knowledge to reduce phytate content in rice seeds, thereby increasing micronutrient bioavailability without compromising plant immunity, health and yield. In short, the discoveries will help to enhance PUE, preserve P-deposits, mitigate the detrimental consequences of excessive P-fertilization and improve the nutritional value of rice.