Peculiarity of transcriptional and H3K27me3 dynamics during peach bud dormancy

Abstract

Bud dormancy facilitates the survival of meristems under harsh environmental conditions. To elucidate how molecular responses to chilling accumulation controlling dormancy in peach buds, chromatin immunoprecipitation sequencing to identify the H3K27me3 modifications and RNA sequencing of two peach cultivars with pronounced differences in chilling requirement were carried out, the results showed that genes associated with abscisic acid and gibberellic acid signal pathways play key roles in dormancy regulation. The results demonstrated that peach flower bud differentiation occurred continuously in both cultivars during chilling accumulation, which was correlated with the transcript abundance of key genes involved in phytohormone metabolism and flower bud development under adverse conditions. The more increased strength in high chilling-requirement cultivar along with the chilling accumulation at the genome-wide level. The function of the dormancy-associated MADS-box gene PpDAM6 was identified, which is involved in leaf bud break in peach and flower development in transgenic Nicotiana tabacum (NC89). In addition, PpDAM6 was positively regulated by PpCBF, and the genes of putative dormancy-related and associated with metabolic pathways were proposed. Taken together, these results constituted a theoretical basis for elucidating the regulation of peach bud dormancy transition.