title: Foliar application of GA3 during terminal long-shoot bud development stimulates shoot apical meristem activity in Pinus sylvestris seedlings.
abstract: The effect of exogenous gibberellin (GA3) on shoot apical meristem activity in conifer vegetative buds was investigated by spraying 0 or 0.1% GA3 on the foliage of first-year Scots pine (Pinus sylvestris L.) seedlings twice weekly for 9 weeks during development of the terminal long-shoot bud. Exogenous GA3 promoted mitotic activity in the apical zone, thereby increasing both the rate and duration of cataphyll formation and giving rise to a higher and wider apical meristem. The increase in number of cataphylls increased the number of axillary meristems, which developed as short-shoot buds.
authors.affiliation: Natural Resources Canada, Canadian Forest Service-Atlantic Forestry Centre, Fredericton, NB E3B 5P7, Canada. jomacdon@nrcan.gc.ca
authors.forename: Joanne E
authors.initials: JE
authors.lastname: MacDonald
authors.forename: C H Anthony
authors.initials: CH
authors.lastname: Little
mesh_terms: D002454:Cell Differentiation / Q000187:drug effects; D005875:Gibberellins / Q000494:pharmacology*; D018519:Meristem / Q000166:cytology / Q000187:drug effects* / Q000254:growth & development; D008938:Mitosis / Q000187:drug effects; D041605:Pinus sylvestris / Q000166:cytology / Q000187:drug effects* / Q000254:growth & development; D010937:Plant Growth Regulators / Q000494:pharmacology*; D036226:Seedlings / Q000166:cytology / Q000187:drug effects* / Q000254:growth & development; D013997:Time Factors; D014197:Trees / Q000166:cytology / Q000187:drug effects* / Q000254:growth & development
chemical_list: D005875:Gibberellins; D010937:Plant Growth Regulators; C007842:gibberellic acid