Milestones in understanding transport, sensing, and signaling of the plant nutrient phosphorus

Abstract

As an essential nutrient element, phosphorus (P) is primarily acquired and translocated as inorganic phosphate (Pi) by plant roots. Pi is often sequestered in the soil and becomes limited for plant growth. Plants have developed a sophisticated array of adaptive responses, termed P starvation responses (PSRs), to cope with P deficiency by improving its external acquisition and internal utilization. Over the past two to three decades, remarkable progress has been made toward understanding how plants sense and respond to changing environmental P. This review provides an overview of the molecular mechanisms that regulate or coordinate PSRs, emphasizing P transport, sensing and signaling. We present the major players and regulators responsible for Pi uptake and translocation. We then introduce how P is perceived at the root tip, how systemic P signaling is operated, and the mechanisms by which the intracellular P status is sensed and conveyed. Additionally, the recent exciting findings about the influence of P on plant-microbe interactions are highlighted. Finally, the challenges and prospects concerning the interplay between P and other nutrients and strategies to enhance P utilization efficiency are discussed. Insights obtained from this knowledge may guide future research endeavors in sustainable agriculture.

Soybean PHR1-regulated low phosphorus-responsiveGmRALF22increases uptake of phosphate via stimulatingGmPTs expression

“…In P-deficient conditions, the MYB domain transcription factor PHR1 is constitutively expressed, and directly induces the expression of Phosphate Transporter 1 ( PHT1) to promote Pi uptake (Yang et al, 2024). Apart from its role in controlling Pi transport, PHR1 also inhibits plant defense by activating JA biosynthesis (Castrillo et al, 2017).…”

Protein pyrophosphorylation by inositol phosphates: a novel post-translational modification in plants?

“…Several recent studies determined that inositol (pyro)phosphates play fundamental roles during phosphate starvation responses (PSRs) in several organisms, including plants. In Arabidopsis and rice, for instance, the promoter binding capacity of PHR transcription factors were proposed to be modulated by binding to SPX-domain containing proteins, a process that is dependent on PP-InsPs (i.e., by stabilizing the PHR-SPX interaction), therefore blocking expression of PSI genes at Pi-replete conditions ( Wild et al., 2016 ; Dong et al., 2019 ; Zhu et al., 2019 ; Land et al., 2021 ; Riemer et al., 2021 ; Gulabani et al., 2022 ; Yang et al., 2024 ). Even though this transcriptional control occurs likely via PP-InsP allosteric binding to basic clusters at the surface of SPX domains ( Wild et al., 2016 ), one cannot exclude that these molecules also modulate Pi responses at post-transcriptional levels downstream of PHR activation, in addition to SPX binding.…”

Response Surface Methodology for Development of Nutrient Solution Formula for Hydroponic Lettuce Based on the Micro-Elements Fertilizer Requirements at Different Growth Stages

“…Many previous studies have mainly focused on the influence of nutrient solution formulation on yield and paid less attention to other quality indicators of lettuce [39,43]. In this study, quadratic regression models (Table 5) of four factors (P, K, Ca, Mg) of the yield and quality indices (SPAD, soluble sugar content, Vc content) of lettuce were established using the response surface method.…”