Variety and Environmental Factors Affecting Pru p 7 Level in Peach Fruit: Implications for Low-Pru p 7 Germplasm Selection

Pru p 7 is a clinically important peach allergen associated with severe allergic reactions, its quantitative variation and environmental determinants remain poorly understood. Using a sensitive sELISA, we quantified Pru p 7 in 123 core peach accessions and assessed variation across tissues, developmental stages, fruit traits, and environmental conditions. Pru p 7 predominated in flesh (0.11–51.89 μg/g fresh weight (FW)), with extremely low levels in wild accessions (mean, 0.20 μg/g FW). Its content varied among cultivars and was associated with flesh color, soluble solid content, aroma, and ripening date. May/June-ripening accessions averaged 21.15 μg/g FW, nearly 6-fold higher than August-ripening accessions. Immunolocalization and IgE immunoblotting supported these quantitative findings. Opaque bagging reduced Pru p 7, particularly in flesh. Three-day storage at 28 °C and 15-day storage at 4 °C also decreased levels in most accessions. These results identify low-Pru p 7 germplasm and practical strategies for allergen-risk management in peach production.