Senescence associated markers to evaluate the quality in postharvest of rocket fresh cut leaves

Senescence is a degenerative process that inevitably affects the quality and the shelf life of fresh cut leafy vegetables. The occurrence of abiotic stresses during the productive chain as well as inadequate or poor handling practices during harvest, processing and packing greatly influence the quality of the final product by accelerating leaf senescence. The aim of our research is to isolate molecular markers for the quality assessment of rocket (Diplotaxis tenuifolia L.) after harvest by using next generation sequencing (NGS) technology. Rocket was grown in floating systems in controlled growth chambers until the plants reached the baby leaf commercial stage. After the harvest, stress was applied for 24 hours by chilling (4°C), mechanical wounding and dark storage. Total RNA was extracted from stressed and control plants and sequenced using a two paired-end Illumina sequencing approach. The downstream bioinformatics analysis allowed to identify interesting candidate genes that showed an up-and a down-regulation specific to each stress as well as common to all the stresses. These genes encode for proteins associated with senescence, degenerative processes and quality loss. These stress related genes will be considered as quality molecular markers and their expression levels will be analyzed by qPCR under several conditions during the storage chain of rocket.