title: Epigenetic and physiological effects of gibberellin inhibitors and chemical pruners on the floral transition of azalea.
abstract: The ability to control the timing of flowering is a key strategy in planning the production of ornamental species such as azaleas; however, it requires a thorough understanding of floral transition. DNA methylation is involved in controlling the functional state of chromatin and gene expression during floral induction pathways in response to environmental and developmental signals. Plant hormone signalling is also known to regulate suites of morphogenic processes in plants and its role in flowering-time control is starting to emerge as a key controlling step. This work investigates if the gibberellin (GA) inhibitors and chemical pinching applied in improvement of azalea flowering alter the dynamics of DNA methylation or the levels of polyamines (PAs), GAs and cytokinins (CKs) during floral transition, and whether these changes could be related to the effects observed on flowering ability. DNA methylation during floral transition and endogenous content of PAs, GAs and CKs were analysed after the application of GA synthesis inhibitors (daminozide, paclobutrazol and chlormequat chloride) and a chemical pruner (fatty acids). The application of GA biosynthesis inhibitors caused alterations in levels of PAs, GAs and CKs and in global DNA methylation levels during floral transition; also, these changes in plant growth regulators and DNA methylation were correlated with flower development. DNA methylation, PA, GA and CK levels can be used as predictive markers of plant floral capacity in azalea.
authors.affiliation: Laboratorio de Fisiología Vegetal, Dpto. B.O.S., Facultad de Biología, Universidad de Oviedo, C/ Cat. Rodrigo Uría s/n, E-33071, Oviedo, Asturias, Spain.
authors.forename: Mónica
authors.initials: M
authors.lastname: Meijón
authors.forename: María Jesús
authors.initials: MJ
authors.lastname: Cañal
authors.forename: Luis
authors.initials: L
authors.lastname: Valledor
authors.forename: Roberto
authors.initials: R
authors.lastname: Rodríguez
authors.forename: Isabel
authors.initials: I
authors.lastname: Feito
mesh_terms: D002716:Chlormequat / Q000494:pharmacology; D003583:Cytokinins / Q000032:analysis; D019175:DNA Methylation / Q000187:drug effects; D018744:DNA, Plant / Q000378:metabolism; D044127:Epigenesis, Genetic; D005227:Fatty Acids / Q000494:pharmacology; D035264:Flowers / Q000187:drug effects* / Q000254:growth & development; D018506:Gene Expression Regulation, Plant; D005875:Gibberellins / Q000032:analysis / Q000037:antagonists & inhibitors*; D010937:Plant Growth Regulators / Q000037:antagonists & inhibitors*; D011073:Polyamines / Q000032:analysis; D029793:Rhododendron / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development; D013386:Succinates / Q000494:pharmacology; D014230:Triazoles / Q000494:pharmacology
chemical_list: D003583:Cytokinins; D018744:DNA, Plant; D005227:Fatty Acids; D005875:Gibberellins; D010937:Plant Growth Regulators; D011073:Polyamines; D013386:Succinates; D014230:Triazoles; C053370:paclobutrazol; D002716:Chlormequat; C014499:daminozide