From Soil to Cell: Systemic Signalling and Regulatory Networks in Zea mays Under Phosphorus Deprivation

Phosphorus (P) is an essential macronutrient that plays a pivotal role in plant growth and productivity. However, its limited availability in many agricultural soils poses a major constraint to crop yields, particularly in maize (Zea mays), a globally important cereal. Low P-use efficiency (PUE) in conventional cropping systems, together with the finite reserves of phosphate rock, highlights the urgency of developing sustainable approaches to enhance PUE. While previous reviews have largely considered soil P dynamics, plant responses, or microbial contributions independently, this review provides an integrated perspective that advances a systems-level understanding of maize adaptation to P deficiency. In the present review, we examine soil P bioavailability, the physiological and molecular mechanisms underpinning maize responses and the regulatory networks that coordinate adaptive strategies. Particular emphasis is placed on the remodelling of root system architecture (RSA) and its interaction with microbial symbionts, including arbuscular mycorrhizal fungi (AMF) and phosphate-solubilizing bacteria (PSB). Beyond individual symbionts, we discuss emerging evidences that P scarcity restructures rhizosphere microbial communities and alters microbe-microbe interaction networks, collectively influencing P mobilization and uptake in maize an aspect often overlooked in earlier reviews. Furthermore, the review highlights that future research should adopt integrative and multidisciplinary approaches to devise sustainable strategies for managing phosphorus limitation in maize cultivation.