Understanding low-phosphate stress responses in plants: Opportunities for genome editing to improve phosphorous use efficiency (PUE)

Abstract

Phosphorus (P) is a critical macronutrient essential for plant growth, yet its availability in soil is often limited due to poor mobility and fixation with metal ions due to acidic or alkaline soils. Plants have evolved complex adaptive responses to overcome phosphate (Pi) deficiency. Recent advancements in genome editing, particularly CRISPR/Cas tools, offer opportunities to enhance these adaptive traits for sustainable agriculture. This review consolidates current understanding of low Pi stress signaling pathways, including morphological (root architecture changes), biochemical (hormone regulation, lipid modification, organic acid exudation), and molecular (transcription factors (TFs), phosphate transporters, and microRNAs), and identifies prime candidate genes for genome editing applications. Key regulators such as phosphate transporter (PHT, PHO1), TFs (PHR1, WRKYs) and microRNAs (miR399/827) manage Pi uptake, redistribution, and signaling. Genome editing strategies targeting root-specific traits, hormonal integration, lipid remodeling, and transcriptional regulation are discussed as viable ways for improving phosphorous use efficiency (PUE). Harnessing CRISPR/Cas tools can lead to the development of crops with optimized PUE, reduced dependency on synthetic fertilizers, and improved adaptability to Pi-deficient soils. The review provides a comprehensive roadmap for researchers and breeders to apply CRISPR/Cas technology toward building next-generation crops capable of thriving under low Pi conditions.