StrawVOC: The role of methylome signatures in regulating post-harvest strawberry quality and aroma

Fresh produce, e.g., soft fruit such as strawberries, are highly perishable, and the underlying genetic control of the fruit ripening and senescence processes resulting in spoilage are still poorly understood. Harvesting the fruit too early results in a lack of flavor, whereas softening that occurs later in ripening limits shelf life. Chilled storage delays softening and spoilage but affect aroma development and quality. A recent analysis of RNASeq has shown that within the first 5 days of chilled storage, there are global changes in patterns of volatile organic compounds(VOCs) comprising the aroma and global gene expression changes. In particular, the expression of several genes related to DNA methylation is altered. DNA methylation is a vital process in fruit ripening and has been found in other fruit, e.g., tomatoes, to change during chilled storage. Results of the hyper or hypo methylation process express key transcription factors that regulate downstream processes such as the biosynthesis of aroma compounds. This project's key objective is to assess the contribution of DNA methylation to postharvest changes in strawberry fruit quality and aroma. A genome-wide assessment of methylation status will identify methylation changes during strawberry fruit postharvest storage, comparing fruit at harvest and after 5 days of chilled storage. These will be compared to transcriptional changes to identify regulatory targets for testing via transient gene expression in fruit and as future breeding targets. In parallel, those data will benefit the generation of segregating populations for postharvest quality. Outputs from the project will be a new resource mapping the methylome during strawberry postharvest and potential biotechnological or conventional breeding targets to improve strawberry postharvest quality.