Plant Immune Elicitors for Postharvest Fruit Preservation: Multifunctional Benefits, Emerging Secreted Protein Elicitors, and Future Perspectives.

Fruits contain abundant diverse nutrients and are an essential component of the human diet. Postharvest pathogens cause severe fruit decay and even mycotoxin contamination, leading to enormous economic losses and food safety risks worldwide. Plants have evolved an intricate immune system to counter pathogen attacks, and plant immune elicitors, particularly biogenic elicitors, offer a promising approach for eco-friendly plant disease management. Although mechanistic studies of plant immunity have largely focused on leaf tissues, considerable progress has been made in the application of immune elicitors for controlling postharvest fruit diseases. In this review, we categorize the main types of plant immune elicitors for postharvest disease control, and highlight that certain elicitors possess multifunctional benefits, including improving fruit quality and enhancing fruit abiotic stress tolerance. Meanwhile, we summarize the molecular mechanisms of newly identified secreted protein elicitors. Finally, we outline a roadmap that combines high-throughput screening with artificial intelligence to accelerate the discovery of novel secreted protein elicitors and their plant receptors, while critically assessing translational barriers to their commercial application in fruit preservation.