title: Consistency of polyamine profiles and expression of arginine decarboxylase in mitosis during zygotic embryogenesis of Scots pine.
abstract: In this study, we show that both arginine decarboxylase (ADC) protein and mRNA transcript are present at different phases of mitosis in Scots pine (Pinus sylvestris) zygotic embryogenesis. We also examined the consistency of polyamine (PA) profiles with the effective temperature sum, the latter indicating the developmental stage of the embryos. PA metabolism was analyzed by fitting statistical regression models to the data of free and soluble conjugated PAs, to the enzyme activities of ADC and ornithine decarboxylase (ODC), as well as to the gene expression of ADC. According to the fitted models, PAs typically had the tendency to increase at the early stages but decrease at the late stages of embryogenesis. Only the free putrescine fraction remained stable during embryo development. The PA biosynthesis strongly preferred the ADC pathway. Both ADC gene expression and ADC enzyme activity were substantially higher than putative ODC gene expression or ODC enzyme activity, respectively. ADC gene expression and enzyme activity increased during embryogenesis, which suggests the involvement of transcriptional regulation in the expression of ADC. Both ADC mRNA and ADC protein localized in dividing cells of embryo meristems and more specifically within the mitotic spindle apparatus and close to the chromosomes, respectively. The results suggest the essential role of ADC in the mitosis of plant cells.
authors.affiliation: Department of Biology , University of Oulu, 90014 Oulu, Finland. jaana.vuosku@oulu.fi
authors.forename: Jaana
authors.initials: J
authors.lastname: Vuosku
authors.forename: Anne
authors.initials: A
authors.lastname: Jokela
authors.forename: Esa
authors.initials: E
authors.lastname: Läärä
authors.forename: Mira
authors.initials: M
authors.lastname: Sääskilahti
authors.forename: Riina
authors.initials: R
authors.lastname: Muilu
authors.forename: Suvi
authors.initials: S
authors.lastname: Sutela
authors.forename: Teresa
authors.initials: T
authors.lastname: Altabella
authors.forename: Tytti
authors.initials: T
authors.lastname: Sarjala
authors.forename: Hely
authors.initials: H
authors.lastname: Häggman
mesh_terms: D002262:Carboxy-Lyases / Q000235:genetics / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D008938:Mitosis; D009955:Ornithine Decarboxylase / Q000235:genetics / Q000378:metabolism; D041605:Pinus sylvestris / Q000166:cytology / Q000196:embryology* / Q000201:enzymology / Q000378:metabolism*; D011073:Polyamines / Q000378:metabolism*; D012639:Seeds / Q000166:cytology / Q000378:metabolism
chemical_list: D011073:Polyamines; D002262:Carboxy-Lyases; D009955:Ornithine Decarboxylase; C019722:arginine decarboxylase