Molecular Mechanisms of Cadmium Stress Resistance in Vegetable Crops

Cadmium (Cd) stress poses significant threats to vegetable crops, impacting their growth, physiological processes, and safety as part of the human food chain. This review systematically summarizes the latest advances in the molecular mechanisms of vegetable crops' resistance to Cd stress. First, physiological and biochemical responses are outlined, including growth inhibition, impaired photosynthesis, oxidative stress, disrupted nutrient absorption, altered phytohormone levels, and gene expression changes. Next, key molecular mechanisms are discussed, focusing on the roles of transporter-related genes (e.g., NRAMP, HIPP, ABCG), transcription factors (e.g., HsfA1a, WRKY, ERF), enzyme-related genes (e.g., E3 ubiquitin ligase, P-type ATPase), microRNAs (e.g., miR398), and potential functional genes in Cd uptake, translocation, and detoxification. Additionally, the regulatory roles of phytohormones and their analogues (e.g., brassinosteroids, gibberellin, salicylic acid) in mitigating Cd toxicity are analyzed, highlighting their involvement in antioxidant defense, gene regulation, and stress signaling pathways. Finally, future research directions are proposed, emphasizing species-specific defense mechanisms, root hair-specific Cd exclusion mechanisms, and interdisciplinary approaches integrating AI and microbiome manipulation. This review provides a comprehensive reference for enhancing Cd stress resistance in vegetable crops and promoting safe crop production.