System Approach Unravels the Fruit Development and Ripening in Apple (Malus x domestica Borkh.)

The fruit physiology in apple, as climacteric fruit, is governed by the action of ethylene. To decipher the functional mechanism controlled by this hormone, two genomic tools were employed. Initially a candidate gene microarray was used to investigate the transcriptional pattern over the fruit development and ripening in ‘Golden Delicious’ apple cultivar. Secondly, a whole genome array was implemented to dissects the effect of ethylene in the postharvest ripening, investigating also the ripening distortion caused by the application of 1-MCP, an ethylene competitor interfering with the hormone at receptor level. The suppression of ethylene perception modifies in fact the ethylene receptor turnover, leading to important modification in the overall fruit physiology. The multidisciplinary correlation analysis network performed showed both positive and negative interaction between transcripts and phenotypic entities (such as fruit texture, volatile organic compounds and polyphenols). The impaired ripening following 1-MCP treatment allowed to step forward into the fruit ripening comprehension, hypothesizing a possible hormonal cross-talk and functional transcriptional regulation.