Role of OsPHR2 on Phosphorus Homeostasis and Root Hairs Development in Rice (Oryza sativa L.)

The study investigated the roles of two PHR genes, OsPHR1 and OsPHR2, in rice, focusing on their involvement in the Pi-signaling pathway and phosphorus homeostasis. It was found that both genes are part of the Pi-signaling pathway, but OsPHR2, when overexpressed, mimicked Pi-starvation stress, leading to enhanced root elongation and increased root hair proliferation, as well as excessive Pi accumulation in shoots under Pi-sufficient conditions. This suggested that OsPHR2 played a role in both systematic and local Pi-signaling pathways, affecting root architecture. The study proposed a hypothetical model for the OsPHR2-regulated Pi-signaling pathway in rice, indicating that OsPHR2 might positively regulate OsmiR399, although OsPHO2 was not significantly affected by OsmiR399 levels. Further research was suggested to explore the regulation mechanisms involved.