title: Epigenetic and hormonal profile during maturation of Quercus Suber L. somatic embryos.
abstract: Somatic embryogenesis is a powerful alternative to conventional mass propagation of Quercus suber L. However, poor quality and incomplete maturation of somatic embryos restrict any application. Given that epigenetic and hormonal control govern many developmental stages, including maturation of zygotic embryos, global DNA methylation and abscisic acid (ABA) were analyzed during development and maturation of cork oak somatic embryos. Our results indicated that development of somatic embryos concurred with a decrease in 5-mdC. In contrast, endogenous ABA content showed a transient increase with a peak in immature E2 embryos denoting the onset of the maturation phase. A cold stratification phase was necessary for embryos to acquire germination ability, which coincided with a significant decrease in 5-mdC and ABA content. Immunohistochemical analyses showed that there was a specific spatial-temporal regulation during embryogenesis, particularly after the cold treatment. The acquisition of germination capacity concurred with a general low 5-mdC signal in the root meristem, while retention of the 5-mdC signal was mainly located in the shoot meristem and provascular tissues. Conversely, ABA immunolocalization was mainly located in the root and shoot apical meristems. Furthermore, a strong decrease in the ABA signal was observed in the root cap after the stratification treatment suggesting a role for the root cap during development of somatic embryos. These results suggest that, in addition to ABA, epigenetic control appears to play an important role for the correct maturation and subsequent germination of cork oak somatic embryos.
authors.affiliation: Lab. Fisiología Vegetal, Dpto. B.O.S., Facultad de Biología, Oviedo University, C/Catedrático Rodrigo Uría, s/n, 33071 Oviedo, Asturias, Spain; Intituto Universitario de Biotecnología de Asturias (IUBA asociado con CSIC), Spain. Electronic address: mar.per.suar@gmail.com.
authors.forename: Marta
authors.initials: M
authors.lastname: Pérez
authors.affiliation: Lab. Fisiología Vegetal, Dpto. B.O.S., Facultad de Biología, Oviedo University, C/Catedrático Rodrigo Uría, s/n, 33071 Oviedo, Asturias, Spain; Intituto Universitario de Biotecnología de Asturias (IUBA asociado con CSIC), Spain. Electronic address: viejomarcos.uo@uniovi.es.
authors.forename: Marcos
authors.initials: M
authors.lastname: Viejo
authors.affiliation: Departamento de Biología Vegetal y Ecología, Facultad de Farmacia, UPV/EHU, Vitoria-Gasteiz E-01006, Spain. Electronic address: maite.lacuesta@ehu.es.
authors.forename: Maite
authors.initials: M
authors.lastname: LaCuesta
authors.affiliation: Royal Botanic Gardens, Kew, Seed Conservation Department, Wakehurst Place, Ardingly, West Sussex RH176TN, UK. Electronic address: p.toorop@kew.org.
authors.forename: Peter
authors.initials: P
authors.lastname: Toorop
authors.affiliation: Lab. Fisiología Vegetal, Dpto. B.O.S., Facultad de Biología, Oviedo University, C/Catedrático Rodrigo Uría, s/n, 33071 Oviedo, Asturias, Spain; Intituto Universitario de Biotecnología de Asturias (IUBA asociado con CSIC), Spain. Electronic address: mjcanal@uniovi.es.
authors.forename: María Jesús
authors.initials: MJ
authors.lastname: Cañal
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism*; D019175:DNA Methylation; D044127:Epigenesis, Genetic; D018525:Germination; D018519:Meristem / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D010937:Plant Growth Regulators / Q000378:metabolism*; D018517:Plant Roots / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D058439:Plant Somatic Embryogenesis Techniques; D029963:Quercus / Q000235:genetics* / Q000254:growth & development / Q000502:physiology; D012639:Seeds / Q000235:genetics / Q000254:growth & development / Q000502:physiology
chemical_list: D010937:Plant Growth Regulators; D000040:Abscisic Acid
keywords: ABA; DNA methylation; Immunolocalization; Maturation; Somatic embryogenesis