|MELLIDOU, I - Katholieke University|
|BUTS, K - Katholieke University|
|HATOUM, D - Katholieke University|
|HO, Q - Katholieke University|
|JOHNSTON, J - Plant And Food Research|
|WATKINS, C - Cornell University - New York|
|SCHAFFER, R - Plant And Food Research|
|GAPPER, N - Cornell University - New York|
|HERTOG, M - Katholieke University|
|NICOLAI, B - Katholieke University|
Submitted to: Biomed Central (BMC) Plant Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/2/2014
Publication Date: 11/28/2014
Citation: Mellidou, I., Buts, K., Hatoum, D., Ho, Q.T., Mattheis, J.P., Johnston, J.W., Watkins, C.B., Schaffer, R.J., Gapper, N.E., Giovannoni, J.J., Rudell Jr, D.R., Hertog, M.L., Nicolai, B.M. 2014. Transcriptomic events associated with internal browning of apple during postharvest storage. Biomed Central (BMC) Plant Biology. 14:328.
Interpretive Summary: Internal browning during storage impacts ‘Braeburn’ apples worldwide. This study used gene expression profiling determine chemical changes in the flesh of the fruit as injury develops. Understanding aberrant metabolism during storage can lead to new ways of treating fruit response to changing environments as it transits the supply chain.
Technical Abstract: Although apple (Malus x domestica) is of economic importance, little information is available about the transriptomic profiling of postharvest disorders, particularly internal browning. This study aimed to explore changes in the apple transcriptome associated with development of flesh browning during storage using Illumina RNA sequencing. Samples from a browning-susceptible cultivar (‘Braeburn’) were stored for four months under controlled atmospheres. Based on a visual browning index, the inner and outer cortex of the stored apples was classified as healthy or affected tissue. Over 600 million short single-end reads were mapped onto the reference transcriptome, and differences in the expression profiles between healthy and affected tissues were assessed to identify candidate genes associated with internal browning. Genes related to the energy, lipid, cell wall, redox state and secondary metabolic pathways were induced or repressed in the affected tissues, and the expression levels of several of them were confirmed by real-time quantitative PCR. This study represents the first global expression profiling of browning-related transcripts in apple fruit, and will be relevant for future studies towards improving postharvest life of apple. Additionally, a set of differentially expressed genes was validated in apples stored for various periods at different CA conditions, giving rise to potential biomarkers associated with high risk of browning development in ‘Braeburn’.