Vol. 7, Issue 1, Part C (2025)

Urban hydroponics has emerged as a viable solution to address food insecurity, land scarcity, and climate-induced production shocks in modern cities. However, its productivity remains constrained by abiotic stresses such as salinity, drought-like osmotic fluctuations, oxidative imbalance, and nutrient deficiencies within closed-soilless systems. Biochemical innovations in genome editing, particularly CRISPR/Cas-derived tools, have enabled precise modification of stress-responsive pathways that confer greater resilience and metabolic efficiency in hydroponically cultivated plants. This article examines the evolution and functional mechanisms of genome-editing platforms that regulate transcription factors, antioxidant networks, Osmo protectants, root architecture dynamics, and ionic homeostasis to enhance plant stress tolerance under controlled environment agriculture. Advances in CRISPR-based base editing, prime editing, and programmable epigenome modulation are reviewed in relation to their role in upregulating genes associated with reactive oxygen species scavenging, proline biosynthesis, Na⁺/K⁺ transport, aquaporins, and nutrient assimilation efficiency. Special focus is given to biochemical innovations such as improved Cas variants, engineered guide RNA scaffolds, and targeted expression systems that increase editing accuracy in leafy vegetables, herbs, and high-value crops commonly used in urban hydroponics. The review further discusses integrative strategies combining genome editing with climate-smart hydroponic technologies, including vertical farming automation, LED spectral tuning, and nutrient-film technique optimization. Current challenges involving regulatory frameworks, off-target effects, metabolic trade-offs, and ethical considerations in urban food systems are evaluated. The research concludes that genome editing, when aligned with controlled environment agriculture, provides unprecedented opportunities to design stress-resilient plant varieties optimized for urban hydroponic environments. These innovations hold the potential to transform resource-efficient, climate-resilient, and high-nutrition production systems in rapidly urbanizing regions.