Genetic and environmental factors affecting allergen-related gene expression in apple fruit (Malus domestica L. Borkh).

Freshly consumed apples can cause allergic reactions because of the presence of four classes of allergens, namely, Mal d 1, Mal d 2, Mal d 3, and Mal d 4, and their cross-reactivity with sensitizing allergens of other species. Knowledge of environmental and endogenous factors affecting the allergenic potential of apples would provide important information to apple breeders, growers, and consumers for the selection of hypoallergenic genotypes, the adoption of agronomical practices decreasing the allergenic potential, and the consumption of fruits with reduced amount of allergens. In the present research, expression studies were performed by means of real-time PCR for all the known allergen-encoding genes in apple.