Chromatin and transcription dynamics regulate flower development during chilling accumulation in peach buds

In deciduous fruit trees, entrance into dormancy occurs in later summer/fall, concomitantly with the shortening of day length and decrease in temperature. Generally speaking, dormancy can be divided into endodormancy, ecodormancy and paradormancy. In Prunus species flower buds, entrance into the dormant stage occurs when the apical meristem is partially differentiated; during dormancy, flower verticils continue their growth and differentiation. In this work we focused our attention on flower bud development during winter in peach. In order to understand how bud development progress is regulated during winter we integrated cytological epigenetic and chromatin genome wide data with transcriptional outputs to obtained a complete picture of the main regulatory pathways involved in endodormancy. Overall design: ChIP-Seq analysis of H3K4me3 and H3K27me3 histone modification dynamics winter dormancy process in peach flower bud development. Flower buds were collected at three time points, corresponding to 0, 475 and 770 chilling units (CU), during the autumn/winter vegetative arrest season.