Crop root system phenotyping with high water-use efficiency and its targeted precision regulation: Present and prospect

Roots are essential to crop survival and productivity, especially under drought conditions where efficient water use efficiency (WUE) is critical for enhancing crop resilience and ensuring food security. This paper explores recent advancements in understanding and optimizing root system architecture (RSA) to enhance WUE, focusing on how genetic, physiological, and environmental factors shape RSA for improved water absorption and drought resilience in major field crops. Root system traits play key roles in accessing water efficiently, and precision manipulation of these traits holds promise for mitigating water scarcity impacts on agriculture. Emerging technologies like multi-omics approaches, which integrate genomics, transcriptomics, and metabolomics, alongside high-throughput imaging techniques, enable comprehensive root phenotyping and real-time monitoring of RSA under varying conditions. These advancements facilitate the identification of key regulatory genes and molecular pathways responsible for efficient water uptake, opening doors to targeted crop breeding and engineering. Additionally, the use of plant growth regulators, plant growth promoting rhizobacteria, and precision irrigation strategies are presented as practical methods to optimize RSA for WUE. The paper also emphasizes the need for interdisciplinary approaches, integrating crop genetics, environmental sciences, and precision agriculture to optimize RSA for sustainable water management. This study highlights the significance of RSA in improving crop productivity under water-limited conditions, offering actionable insights for future research aimed at developing drought-resistant crops and optimizing water resources. By filling the existing research gap, this paper provides a comprehensive framework for advancing field crop resilience through the integration of RSA shaping, advanced technologies, and improved water management practices. • The characteristics of ideal RSA with high WUE are defined. • Molecular and multi-omics mechanisms enhance understandings on ideal RSA with high WUE. • High-throughput imaging for crop root phenotyping is essential for identifying ideal RSA with high WUE. • Precision management approaches are required for establishing ideal RSA with high WUE. • Multi-omics-driven model is an effective approach to optimize ideal RSA with high WUE. • Integration of technical approaches is important for addressing the key issues of ideal RSA with high WUE.