Phosphate starvation: response mechanisms and solutions

Abstract

Phosphorus is essential to plant growth and agricultural crop yields, yet the challenges associated with phosphorus fertilization in agriculture, such as aquatic runoff pollution and poor phosphorus bioavailability, are increasingly difficult to manage. Comprehensively understanding the dynamics of phosphorus uptake and signaling mechanisms will inform the development of strategies to address these issues. This review describes regulatory mechanisms used by specific tissues in the root apical meristem to sense and uptake phosphate from the rhizosphere. The major regulatory mechanisms and related hormone crosstalk underpinning phosphate starvation responses, cellular phosphate homeostasis, and plant adaptations to phosphate starvation are also discussed in this review. In addition, this review overviews the major mechanism of plant systemic phosphate starvation responses. Finally, this review discusses recent promising genetic engineering strategies for improving crop phosphorus use and computational approaches that may help further design strategies for improved plant phosphate acquisition. The mechanisms and approaches presented in this review include a wide variety of species not only including Arabidopsis thaliana but also including crop species such as Oryza sativa (rice), Glycine max (soybean), and Triticum aestivum (wheat) to address both general and species-specific mechanisms and strategies. The aspects of phosphorus deficiency responses and recently employed strategies of improving phosphate acquisition that are detailed in this review may provide insights on the mechanisms or phenotypes that may be targeted in efforts to improve crop phosphorus content and plant growth in low phosphorus soils.

Beneficial Effects of Phosphite in <em>Arabidopsis thaliana</em> Are Mediated by Activation of ABA, SA, and JA Biosynthesis and Signaling Pathways

“…We found that under LPi conditions, the treatment with 50 mM Phi severely reduced shoot and root growth (Figure 1). In Pi-deprived seedlings, 50 mM Phi also attenuated the formation of lateral roots and the accumulation of anthocyanins, which are characteristic components of the PSR in Arabidopsis [29,30]. Phi negatively impacted metrics associated with the root architecture, such as lateral root number, primary root length, root weight, total root length, and convex hull (Figure 1ej).…”

The MYB-CC Transcription Factor PHOSPHATE STARVATION RESPONSE-LIKE 7 (PHL7) Functions in Phosphate Homeostasis and Affects Salt Stress Tolerance in Rice

“…P is a major macronutrient that strongly influences plant growth and productivity, including in rice ( Oryza sativa ), a major crop worldwide [ 3 , 4 ]. Phosphorus stress negatively regulates metabolic processes [ 5 , 6 , 7 ], and plants have evolved various adaptive strategies that enable them to withstand this stress. To cope with limited phosphate availability, plants have developed a phosphate homeostasis mechanism that mobilizes and stores Pi from soil, which is utilized under stress [ 4 ].…”