title: Promotion of flowering in azaleas by manipulating photoperiod and temperature induces epigenetic alterations during floral transition.
abstract: The ability to control the timing of flowering is a key strategy for planning production in ornamental species such as the azalea; however, this requires a thorough understanding of floral induction pathways. DNA methylation is one of the main mechanisms involved in controlling the functional state of chromatin and gene expression in response to environmental and developmental signals. This work investigated the promotion of flowering in azaleas by the manipulation of environmental factors, using DNA methylation levels as a marker of floral bud development. The results showed that the change of long-day (LD) to short-day (SD) photoperiod is the primary factor responsible for floral induction in azaleas, whereas the existence of the previous cold period as well as the physiological memory are factors which improve floral production. Furthermore, for blooming to take place, 1300 units of growing degree days under an LD were necessary. The promotion of flowering in azaleas by alterations of photoperiod and temperature induced DNA methylation changes. The demethylation observed after the change from LD to SD is linked to a change in cell fate which is necessary for floral transition to take place and seems to be associated with the floral signal.
authors.affiliation: Laboratorio de Fisiología Vegetal, Dpto. B.O.S., Facultad de Biología, Universidad de Oviedo, C/Cat. Rodrigo Uria s/n, E-33071 Oviedo, Asturias, Spain.
authors.forename: Mónica
authors.initials: M
authors.lastname: Meijón
authors.forename: Isabel
authors.initials: I
authors.lastname: Feito
authors.forename: Luis
authors.initials: L
authors.lastname: Valledor
authors.forename: Roberto
authors.initials: R
authors.lastname: Rodríguez
authors.forename: María Jesús
authors.initials: MJ
authors.lastname: Cañal
mesh_terms: D019175:DNA Methylation; D044127:Epigenesis, Genetic; D035264:Flowers / Q000235:genetics* / Q000254:growth & development; D018506:Gene Expression Regulation, Plant; D014644:Genetic Variation; D008954:Models, Biological; D017440:Photoperiod; D029793:Rhododendron / Q000235:genetics* / Q000254:growth & development; D012621:Seasons; D013030:Spain; D013696:Temperature