Factors affecting gene expression of LTP (Lipid Transfer Protein), the major allergen of peach fruit

Considering the increase of fruit allergy diseases, a specific research on some molecular aspects of Lipid Transfer Protein (LTP), the major allergen of peach, has been carried out. Fruits of four peach cultivars (Sentry, Royal Gemm, Summered, Tardiva Zuliani) were harvested in correspondence of commercial ripeness and stored at 20°C or at 4°C. A 269bp cDNA fragment (named Pp-LTP1) was PCR-synthesized from poly A+ mRNA extracted from epicarp of cv Sentry, using degenerated primers. Sequencing analysis revealed that Pp-LTP1 encodes a protein belonging to the LTP family. Southern analysis indicated that Pp-LTP1 belongs to a small multigenic family of at least three members. Expression analysis showed that Pp-LTP1 mRNA is present in epicarp but not in mesocarp of ripe fruit and that specific transcript accumulation remains unchanged throughout postharvest ripening at 20°C. Storage at low temperatures induced a decrease of Pp-LTP1 transcript accumulation in cv Sentry and Tardiva Zuliani but not in Royal Gemm and SummeRed.