European Journal of Sustainable Agroecosystems

Background: Climate-driven accelerations in global aridity underscore the urgent requirement to engineer crop cultivars with optimized water-use efficiency. Root hydraulic conductivity (Lpr), which governs the volumetric water flux across the root cylinder per unit of driving force, constitutes a fundamental yet highly dynamic determinant of whole-plant water acquisition strategies.

Objective: This critical review provides an extensive synthesis and critical evaluation of the biophysical, anatomical, and molecular mechanisms modulating Lpr, evaluates divergent crop transport strategies under abiotic stress, and dissects the major methodological limitations within current literature.

Methodology: A systematic literature search across Scopus, Web of Science, PubMed, ScienceDirect, and Google Scholar was performed for the publication window 2015–2025 using targeted Boolean search strings. A total of 142 high-impact peer-reviewed studies were selected via a rigorous PRISMA-style selection framework.

Major Findings: Critical evidence synthesis indicates that Lpr is regulated by a complex interplay between structural components (endodermal suberin lamellae deposition, Casparian strip chemistry, and metaxylem vessel architecture) and metabolic elements governed by the gating, phosphorylation, and abundance of aquaporins (AQPs). Under drought and salinity, crops display highly divergent adaptive strategies, spanning from severe transcriptional downregulation of Plasma membrane Intrinsic Proteins (PIPs) to minimize back-flow, to localized upregulation of active water channels to maximize patchily distributed moisture reserves.

Research Gaps: Significant knowledge gaps persist regarding the non-destructive spatial mapping of Lpr variations across specific root zones, post-translational AQP kinetics in full field microclimates, and the translation of juvenile seedling models into mature yield phenotypes.

Conclusion: Resolving these contradictions necessitates integrating automated functional-structural plant modeling (FSPM) with cell-specific gene editing, offering a concrete roadmap for engineering climate-resilient crop platforms.