title: Gibberellins in shoots and developing capsules of Populus species.
abstract: Extracts of stems of growing shoots of Populus deltoides and P. trichocarpa, and developing capsules of P. deltoides were analysed for gibberellins (GAs) by gas chromatography-mass spectrometry. The following known GAs were identified by comparison of their Kovats retention indices (KRIs) and mass spectra with those of standards: GA1, GA8, GA9, GA19, GA20, 16 beta,17-dihydro-17-hydroxy GA20, GA23, GA28, GA29, GA34, GA44, and GA97. Several of these have not been previously reported from Populus. In addition, two new GAs were identified as 12 beta-hydroxy GA53 (GA127) and 16 beta,17-dihydro-17-hydroxy GA53 and their structures were confirmed by partial synthesis. Evidence was found of 16,17-dihydro-16,17-dihydroxy GA9, 16,17-dihydro-16,17-dihydroxy GA12, 12-hydroxy GA14, and GA34-catabolite by comparison of mass spectra and KRIs with published data. Several putative GAs (hydroxy- and dihydroxy-GA12-like) were also found. The catabolites of active GAs or of key precursors, hydroxylated at C-2 in stems and either C-2, C-12, C-17, or C-16,17 in capsules, were the major proportion of the GAs.
authors.affiliation: Department of Biological Sciences, University of Lethbridge, Lethbridge, Alberta T1K 3M4, Canada. pearce@uleth.ca
authors.forename: David W
authors.initials: DW
authors.lastname: Pearce
authors.forename: Oliver E
authors.initials: OE
authors.lastname: Hutt
authors.forename: Stewart B
authors.initials: SB
authors.lastname: Rood
authors.forename: Lewis N
authors.initials: LN
authors.lastname: Mander
mesh_terms: D008401:Gas Chromatography-Mass Spectrometry; D005875:Gibberellins / Q000032:analysis*; D018520:Plant Shoots / Q000737:chemistry; D031308:Salicaceae / Q000737:chemistry*
chemical_list: D005875:Gibberellins