title: The MADS-box gene DAL1 is a potential mediator of the juvenile-to-adult transition in Norway spruce (Picea abies).
abstract: Progression through the plant life cycle involves change in many essential features, most notably in the capacity to reproduce. The transition from a juvenile vegetative and non-reproductive to an adult reproductive phase is gradual and can take many years; in the conifer Norway spruce, Picea abies, typically 20-25 years. We present a detailed analysis of the activities of three regulatory genes with potential roles in this transition in Norway spruce: DAL1, a MADS-box gene related to the AGL6 group of genes from angiosperms, and the two LEAFY-related genes PaLFY and PaNLY. DAL1 activity is initiated in the shoots of juvenile trees at an age of 3-5 years, and then increases with age, whereas both LFY genes are active throughout the juvenile phase. The activity of DAL1 further shows a spatial pattern along the stem of the tree that parallels a similar gradient in physiological and morphological features associated with maturation to the adult phase. Constitutive expression of DAL1 in transgenic Arabidopsis plants caused a dramatic attenuation of both juvenile and adult growth phases; flowers forming immediately after the embryonic phase of development in severely affected plants. Taken together, our results support the notion that DAL1 may have a regulatory role in the juvenile-to-adult transition in Norway spruce.
authors.affiliation: Department of Physiological Botany, Evolutionary Biology Center, Uppsala University, Villavägen 6, SE-752 36 Uppsala, Sweden.
authors.forename: Annelie
authors.initials: A
authors.lastname: Carlsbecker
authors.forename: Karolina
authors.initials: K
authors.lastname: Tandre
authors.forename: Urban
authors.initials: U
authors.lastname: Johanson
authors.forename: Marie
authors.initials: M
authors.lastname: Englund
authors.forename: Peter
authors.initials: P
authors.lastname: Engström
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D005809:Genes, Regulator; D026161:MADS Domain Proteins / Q000096:biosynthesis / Q000235:genetics*; D008969:Molecular Sequence Data; D028222:Picea / Q000235:genetics* / Q000254:growth & development*; D018515:Plant Leaves / Q000378:metabolism / Q000648:ultrastructure; D010940:Plant Proteins / Q000096:biosynthesis / Q000235:genetics*; D030821:Plants, Genetically Modified
chemical_list: D026161:MADS Domain Proteins; D010940:Plant Proteins