Recent research on the regulation of cellular phosphate (Pi) homeostasis in eukaryotes has collectively made substantial advances in elucidating inositol pyrophosphates (PP-InsP) as Pi signaling molecules that are perceived by the SPX (Syg1, Pho81, and Xpr1) domains residing in multiple proteins involved in Pi transport and signaling. The PP-InsP-SPX signaling module is evolutionarily conserved across eukaryotes and has been elaborately adopted in plant Pi transport and signaling systems. In this review, we have integrated these advances with prior established knowledge of Pi and PP-InsP metabolism, intracellular Pi sensing, and transcriptional responses according to the dynamics of cellular Pi status in plants. Anticipated challenges and pending questions as well as prospects are also discussed.

 摘 要 

最近关于真核生物中细胞内磷酸盐（Pi）稳态调节的研究在阐明焦磷酸肌醇（PP-InsP）作为Pi信号分子方面取得了重大进展，而参与Pi转运和信号转导的多个蛋白中的SPX结构域负责感知这些信号分子。PP-InsP-SPX信号转导模块在真核生物演化上是保守的，并且很好地被整合到了植物Pi转运和信号转导系统中。本文中，作者综述了相关的研究进展，包括植物体内细胞Pi状态波动下，先前已建立的Pi和PP-InsP代谢、细胞内Pi感知以及转录响应。作者还讨论了未来可预期的挑战、悬而未决的问题以及未来的前景。