LOOKING FOR PLAYERS IN POST-CUT BROWNING MECHANISMS IN EGGPLANT

Among Solanaceous crops, eggplant (Solanum melongena L.) is the third most consumed food species after tomato and potato, representing one of the most economically and nutritionally important plant in Asia and Europe. Selection and breeding over hundreds of years have resulted in the production of a large number of eggplant varieties with improved yield, pest resistance and fruit quality. The high content in antioxidant phenylpropanoids, especially chlorogenic acid and flavonoids (anthocyanins), either in the flesh or skin, mainly accounts for the high nutritional value of eggplant. However, post-cut browning processes due to oxidation of the phenolic fraction may adversely affect the commercial and nutritional value of the fruit. It is reported for various raw and cut fruits and vegetables, that the level of phenolics and their oxidizing enzymes polyphenol oxidases (PPOs) might be key players in the browning process. Little information is reported about the actual mechanisms controlling browning of fresh-cut eggplants. We analysed fruits harvested from 28 accessions of S. melongena for several biochemical parameters such as content in CGA, total phenolics and PPO activities. Lines characterized by comparable parameters were grouped in pools and quantitative analysis of PPO and CGA biosynthetic gene transcripts was carried out for each of them. Correlation analysis indicated that the PPO activity in several pools is consistent with the expression analysis data but overall the content of CGA, PPO activity, browning and expression are not correlated. In order to elucidate whether other players are involved in the browning mechanism in eggplant here we present our genomic and biochemical approaches. This work was supported by the Project GenHORT PON02_00395_3215002 funded by the Italian Ministry of Education, University and Research (MIUR), PON R&C 2007-2013.