Analysis of changes in protein abundance after wounding in ‘Golden Delicious’ apples

Abstract

The apple (Malus×domestica Borkh.) cultivar (cv) ‘Golden Delicious’ is one of the most important apple varieties worldwide, and is widely cultivated for export of fruit to Europe and other countries. However, if damaged, the fruit becomes susceptible to opportunistic infection by postharvest phytopathogens such as Botrytis cinerea (gray mould) and Penicillium expansum (blue mould), which annually lead to large economic losses. Therefore, the study of fruit responses to wounding at the proteome level can contribute to a better understanding of the physiological mechanisms underlying fruit stress responses. In this study we report the first systematic description of the changes in protein abundance following wounding of ‘Golden Delicious’ apples, using 2D-PAGE and MS. At the proteome level, the dominant biological process in wounding response was ‘response to stress’, whereas proteins without abundance changes were found to be mainly involved in ‘metabolism’, ‘response to stress’, and ‘oxidation-reduction processes’. We speculate that fruit respond to wound stress by modulating the abundance of appropriate proteins and to react to mechanical damage by synthesizing a broad range of PR proteins. Therefore, increasing the information on apple fruit proteins after wounding will be a useful resource in developing strategies to minimize postharvest losses.