Abstract Intracellular inorganic orthophosphate (Pi) distribution and homeostasis profoundly affect plant growth and development. However, its distribution patterns remain elusive owing to the lack of efficient cellular Pi imaging methods. Here we develop a rapid colorimetric Pi imaging method, inorganic orthophosphate staining assay (IOSA), that can semi-quantitatively image intracellular Pi with high resolution. We used IOSA to reveal the alteration of cellular Pi distribution caused by Pi starvation or mutations that alter Pi homeostasis in two model plants, rice and Arabidopsis, and found that xylem parenchyma cells and basal node sieve tube element cells play a critical role in Pi homeostasis in rice.
Abstract Inorganic phosphate (Pi) availability is an important factor that affects the growth and yield of crops, thus an appropriate and effective response to Pi-fluctuation is critical. However, how crops orchestrate Pi-signaling and growth under Pi-starvation conditions to optimize the growth defense tradeoff remains unclear. Here we show that a Pi-starvation induced transcription factor NIGT1 (NITRATE-INDUCIBLE GARP-TYPE TRANSCRIPTIONAL REPRESSOR 1) controls plant growth and prevents a hyperresponse to Pi-starvation by directly repressing the expression of growth-related and Pi-signaling genes to achieve a balance between growth and response under a varying Pi environment.
Abstract As a finite and non-renewable resource, phosphorus (P) is essential to all life and crucial for crop growth and food production. The boosted agricultural use and associated loss of P to the aquatic environment are increasing environmental pollution, harming ecosystems, and threatening future global food security. Thus, recovering and reusing P from water bodies is urgently needed to close the P cycle. As a natural, eco-friendly, and sustainable reclamation strategy, microalgae-based biological P recovery is considered a promising solution.
Abstract Phosphate (Pi) is involved in numerous metabolic processes and plays a vital role in plant growth. Green plants have evolved intricate molecular bases of Pi-signaling to maintain cellular Pi homeostasis. Here, we summarize recent advances in the molecular and structural bases of central Pi-signaling and discuss pending questions.
Discovery of the core elements involved in P signaling
(A) Key studies uncovering the molecular and structural basis of P signaling machines.
Abstract Phosphate (Pi) limitation represents a primary constraint on crop production. To better cope with Pi deficiency stress, plants have evolved multiple adaptive mechanisms for phosphorus acquisition and utilization, including the alteration of growth and the activation of Pi starvation signaling. However, how these strategies are coordinated remains largely unknown. Here, we found that the alternative splicing (AS) of REGULATOR OF LEAF INCLINATION 1 (RLI1) in rice (Oryza sativa) produces two protein isoforms: RLI1a, containing MYB DNA binding domain; and RLI1b, containing both MYB and coiled-coil (CC) domains.
