Dynamics of DNA methylation and Histone H4 acetylation during floral bud differentiation in azalea.
BACKGROUND
The ability to control the timing of flowering is a key strategy for planning production in ornamental species such as azalea, however it requires a thorough understanding of floral transition. Floral transition is achieved through a complex genetic network and regulated by multiple environmental and endogenous cues. Dynamic changes between chromatin states facilitating or inhibiting DNA transcription regulate the expression of floral induction pathways in response to environmental and developmental signals. DNA methylation and histone modifications are involved in controlling the functional state of chromatin and gene expression.


RESULTS
The results of this work indicate that epigenetic mechanisms such as DNA methylation and histone H4 acetylation have opposite and particular dynamics during the transition from vegetative to reproductive development in the apical shoots of azalea. Global levels of DNA methylation and histone H4 acetylation as well as immunodetection of 5-mdC and acetylated H4, in addition to a morphological study have permitted the delimitation of four basic phases in the development of the azalea bud and allowed the identification of a stage of epigenetic reprogramming which showed a sharp decrease of whole DNA methylation similar to that is defined in other developmental processes in plants and in mammals.


CONCLUSIONS
The epigenetic control and reorganization of chromatin seem to be decisive for coordinating floral development in azalea. DNA methylation and H4 deacetylation act simultaneously and co-ordinately, restructuring the chromatin and regulating the gene expression during soot apical meristem development and floral differentiation.
Meijón
Mónica
M
Laboratorio de Fisiología Vegetal, Dpto BOS, Facultad de Biología, Universidad de Oviedo, Oviedo, Asturias, Spain.
Feito
Isabel
I
Valledor
Luis
L
Rodríguez
Roberto
R
Cañal
María Jesús
MJ
D000107:Acetylation; D019175:DNA Methylation; D018744:DNA, Plant / Q000378:metabolism; D044127:Epigenesis, Genetic; D035264:Flowers / Q000254:growth & development* / Q000378:metabolism; D006657:Histones / Q000378:metabolism*; D018519:Meristem / Q000254:growth & development / Q000378:metabolism; D029793:Rhododendron / Q000235:genetics / Q000378:metabolism*
D018744:DNA, Plant; D006657:Histones