Mutation of Enhances Tolerance to Phosphate Starvation in Rice.

() encodes a protein localized to the endoplasmic reticulum (ER) and cell wall. This gene plays a key role in responding to phosphate (Pi) deprivation, especially in remodeling the root system architecture (RSA). An identification and expression analysis of the family in rice () has been previously reported, and , functioning in Pi uptake and translocation, is required for the normal growth and development of rice. However, the role of , one of the five members of this family in rice, in response to Pi deficiency and/or in the regulation of plant growth and development is unknown. Therefore, in this study, the roles of in these processes were investigated, and some functions were found to differ between and . was found to be induced in the leaf blades, leaf sheaths, and roots under Pi deprivation. overexpression strongly inhibited the growth and development of the rice but did not affect the Pi homeostasis of the plant. However, mutants improved RSA and Pi utilization, and they exhibited a higher tolerance to low Pi stress in rice. The agronomic traits of the mutants, such as 1000-grain weight and seed length, were stimulated under Pi-sufficient conditions, indicating that plays roles different from those of during plant growth and development, as well as in the maintenance of the Pi status of rice.