Cui‐Ci Sun, Wancong Yu, Yiheng Wang, Yiheng Wang, Wenjie Ge, Menglu Zhang, Shiyong Xu, Qingkuo Lan, Yong Wang, Yong Wang
• Salt injury in cucumber is strongly stage dependent across the life cycle. • Ion balance, water status, and redox control underpin cucumber salt tolerance. • Ca²⁺, ABA, and ROS form a central regulatory hub under salinity. • Grafting, exogenous regulators, and rhizosphere support aid salt tolerance. • Future progress requires stage-resolved phenotyping and field validation. Cucumber ( Cucumis sativus L.) is a salt-sensitive horticultural crop whose productivity and fresh-market quality are increasingly threatened by soil salinization, especially in protected cultivation and irrigated production systems. This review synthesizes current knowledge of cucumber salt tolerance across developmental, physiological, molecular, and translational levels, with emphasis on horticulturally relevant traits and deployment. Salt injury is strongly stage dependent: germination and seedling establishment are highly vulnerable to osmotic and ionic disruption, whereas reproductive-stage instability more directly determines fruit set, marketable yield, and fruit quality. The core physiological basis of salt tolerance includes ion and nutrient homeostasis, osmotic adjustment and hydraulic stability, photosynthetic maintenance, antioxidant buffering, and root-shoot coordination. These physiological responses are organized by a regulatory network centered on Ca²⁺, abscisic acid, and reactive oxygen species and are further shaped by transcription factors, non-coding RNAs, and molecular modules with differing levels of support. At the horticultural level, translational strategies include grafting with salt-tolerant rootstocks, mechanism-based exogenous regulation, rhizosphere-assisted protection, and breeding pipelines coupled with stage-resolved phenotyping. Key gaps remain in reproductive-stage tolerance, Cl⁻ toxicity, nutrient balance, spatiotemporal signaling, and field-relevant validation. Future progress will depend on linking causal network analysis with breeding and production-oriented evaluation to develop cucumber cultivars and cultivation systems with improved performance under saline conditions.