Integrative analysis of crop drought-tolerance genes and soil hydraulic traits: Bridging plant genomics and irrigation physics for sustainable water management: A review

Abstract:

Global agricultural productivity is substantially constrained by drought conditions and water scarcity, impacting approximately 25-40% of arable lands worldwide, particularly in the Middle East, North Africa, and Sub-Saharan Africa. Despite decades of research on crop drought tolerance mechanisms, a persistent disciplinary divide exists: drought-resistant varieties are evaluated by plant breeders under controlled greenhouse conditions that exclude soil variability, while soil physicists model water movement via Richards' equation without accounting for genetic variation in root hydraulic traits. This review synthesizes advances in plant genomics, soil physics, and bio-physical modeling to establish an integrated "physio-genetic" framework for sustainable drought adaptation. Key drought-tolerance genes regulating plant hydraulic traits (including root system architecture genes (DRO1, qSOR1), aquaporins (AQP; PIP1, PIP2, TIP1), and transcription factors “DREB1”) are examined alongside their interactions with soil water conductivity K(θ) and water potential gradients governed by the van Genuchten-Mualem model. Rhizosphere engineering through root exudates and mucilage production is analyzed for its modulation of soil-root hydraulic continuity. Bio-physical modeling approaches that couple crop growth platforms (DSSAT, APSIM) with soil water transport solvers (HYDRUS-1D) are reviewed to predict genotype × soil × climate interactions. Case studies from rainfed rice (DRO1 deployment in Asia) and drought-tolerant maize (marker-assisted selection in the Sahel) document 20-30% and 40-60% yield improvements under water-limited conditions, respectively. Breeding strategies and precision irrigation protocols tailored to soil texture are proposed, alongside identification of adoption barriers and research gaps in climate change projections. This integrative framework advances physio-genetic breeding paradigms that simultaneously optimize plant genetic capacity and soil-plant hydraulic coupling, providing pathways for sustainable water utilization amid escalating climate variability and food security challenges.