Hormonal control of dormancy in sweet cherry flower buds
Résumé
In the context of global change, temperate fruit trees are affected by contradictory effects: increased productivity in relation with longer growing season and insufficient chilling during winter. It is therefore essential to better understand the mechanisms controlling phenology and its response to environmental conditions. Optimal timing and quality of flowering directly depend on adequate dormancy progression during winter and spring, regulated by a combination of chilling and warm temperatures. Physiological, genetic and functional genomic studies have shed light onto the mechanisms underlying dormancy control in deciduous trees. Notably, internal signals such as hormones and sugars were shown to play a key role in dormancy establishment, maintenance and release. In order to further study how these signaling pathway control dormancy progression, we combined transcriptional analyses and quantification of abscisic acid (ABA) and gibberellins (GAs) in sweet cherry flower buds during the dormancy period. Our results suggest that ABA is critical for dormancy maintenance and we propose that the complex balance between ABA and GA pathways regulate the timing for dormancy release.