Analysis of apple fruit proteomes induced by alternative post-harvest treatments

Apple, the most cultivated and utilized fruit tree in temperate climate zones, represents an important and profitable source of food. During post-harvest storage, apples are susceptible to rot caused by latent infection of field pathogens, such as Phlyctema vagabunda (lenticel rot), Botrytis cinerea, and Alternaria alternata, or by pathogens infecting wounds made during harvesting and postharvest handling, such as Penicillium expansum. The control of postharvest pathogens is usually achieved by using synthetic fungicides. However, the development of resistant strains, the difficulties in registering new active substances and the growing concern for the negative effect of chemicals on the environment and the consumer's health have increased the interest for alternative disease control means. The exploitation of natural mechanisms of plants resistance to diseases induced by various factors (IR) has gained attention in many laboratories worldwide as part of an integrated pest management strategy. The objective of our project was to develop a new method for controlling microbial post-harvest pathogens by improving IR in apple fruit. Here we report the results from experiments in which the total proteome of apples subjected to different treatments, including antagonistic microbes, quercetin and essential oils, was obtained at different time points (0, 24 and 48 h post treatment). Several differentially accumulated proteins, separated by 2D-electrophoresis from various apple proteomes, have been isolated and are being identified and characterized by MALDI-TOF analysis.