Enhancement of rice traits for the maintenance of the phosphorus balance between rice plants and the soil

Abstract

Phosphorus (P) is essential for maximizing crop yield, yet many areas dedicated to rice cultivation suffer from a scarcity of plant-accessible inorganic phosphate (Pi) due to its fixation in the soil. Conversely, regions with ample P fertilization often resort to excessive application to compensate for deficiencies, resulting in adverse environmental impacts. While significant strides have been made in understanding the molecular mechanisms governing P uptake capacity (PUP/PAE) and P use efficiency (PUE) in rice, their practical implementation in breeding is impeded by the absence of robust, high throughput phenomics techniques, leading to inconsistencies in gene/quantitative trait loci (QTL) effects. This review underscores the necessity for a comprehensive understanding of Pi transporters, internal Pi remobilization, and root morphology modifications under Pi deficiency, correlating these traits with specific phenotypic markers. Developing precise, cost-effective, high-throughput phenotyping techniques is imperative for creating rice ideotypes with enhanced PAE/PUE. Additionally, we explore the potential of meta-QTL analysis in prioritizing genomic loci related to PUE, utilizing a “meta-genome” encompassing diverse rice reference genomes. We also delve into the potential in the development of phosphite (Phi)-tolerant rice, aiming to reduce dependence on P fertilizers and create herbicide-resistant rice through Phi-based fertilization. Finally, we discuss the utilization of arbuscular mycorrhizal fungi (AMF) to enhance P uptake in rice.