title: Application of proteomics to the study of pollination drops.
abstract: OBJECTIVE
  Pollination drops are a formative component in gymnosperm pollen-ovule interactions. Proteomics offers a direct method for the discovery of proteins associated with this early stage of sexual reproduction. •
  
  
  METHODS
  Pollination drops were sampled from eight gymnosperm species: Chamaecyparis lawsoniana (Port Orford cedar), Ephedra monosperma, Ginkgo biloba, Juniperus oxycedrus (prickly juniper), Larix ×marschlinsii, Pseudotsuga menziesii (Douglas-fir), Taxus ×media, and Welwitschia mirabilis. Drops were collected by micropipette using techniques focused on preventing sample contamination. Drop proteins were separated using both gel and gel-free methods. Tandem mass spectrometric methods were used including a triple quadrupole and an Orbitrap. •
  
  
  RESULTS
  Proteins are present in all pollination drops. Consistency in the protein complement over time was shown in L. ×marschlinsii. Representative mass spectra from W. mirabilis chitinase peptide and E. monosperma serine carboxypeptidase peptide demonstrated high quality results. We provide a summary of gymnosperm pollination drop proteins that have been discovered to date via proteomics. •
  
  
  CONCLUSIONS
  Using proteomic methods, a dozen classes of proteins have been identified to date. Proteomics presents a way forward in deepening our understanding of the biological function of pollination drops.
authors.affiliation: Centre for Forest Biology, Department of Biology, University of Victoria, P.O. Box 3020 Station CSC, Victoria, British Columbia V8W 3N5, Canada.
authors.forename: Natalie
authors.initials: N
authors.lastname: Prior
authors.affiliation: Centre for Forest Biology, Department of Biology, University of Victoria, P.O. Box 3020 Station CSC, Victoria, British Columbia V8W 3N5, Canada.
authors.forename: Stefan A
authors.initials: SA
authors.lastname: Little
authors.affiliation: Arnold Arboretum of Harvard University, 125 Arborway, Boston, Massachusetts 02130-3500 USA.
authors.forename: Cary
authors.initials: C
authors.lastname: Pirone
authors.affiliation: Centre for Forest Biology, Department of Biology, University of Victoria, P.O. Box 3020 Station CSC, Victoria, British Columbia V8W 3N5, Canada.
authors.forename: Julia E
authors.initials: JE
authors.lastname: Gill
authors.affiliation: University of Victoria-Genome BC Proteomics Centre, University of Victoria, Victoria, British Columbia V8Z 7X8, Canada.
authors.forename: Derek
authors.initials: D
authors.lastname: Smith
authors.affiliation: University of Victoria-Genome BC Proteomics Centre, University of Victoria, Victoria, British Columbia V8Z 7X8, Canada.
authors.forename: Jun
authors.initials: J
authors.lastname: Han
authors.affiliation: University of Victoria-Genome BC Proteomics Centre, University of Victoria, Victoria, British Columbia V8Z 7X8, Canada.
authors.forename: Darryl
authors.initials: D
authors.lastname: Hardie
authors.affiliation: Centre for Forest Biology, Department of Biology, University of Victoria, P.O. Box 3020 Station CSC, Victoria, British Columbia V8W 3N5, Canada.
authors.forename: Stephen J B
authors.initials: SJ
authors.lastname: O'Leary
authors.affiliation: Centre for Forest Biology, Department of Biology, University of Victoria, P.O. Box 3020 Station CSC, Victoria, British Columbia V8W 3N5, Canada.
authors.forename: Rebecca E
authors.initials: RE
authors.lastname: Wagner
authors.affiliation: University of Victoria-Genome BC Proteomics Centre, University of Victoria, Victoria, British Columbia V8Z 7X8, Canada.
authors.forename: Tyra
authors.initials: T
authors.lastname: Cross
authors.affiliation: Centre for Forest Biology, Department of Biology, University of Victoria, P.O. Box 3020 Station CSC, Victoria, British Columbia V8W 3N5, Canada.
authors.forename: Andrea
authors.initials: A
authors.lastname: Coulter
authors.affiliation: University of Victoria-Genome BC Proteomics Centre, University of Victoria, Victoria, British Columbia V8Z 7X8, Canada ; Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8P 5C2, Canada.
authors.forename: Christoph
authors.initials: C
authors.lastname: Borchers
authors.affiliation: University of Victoria-Genome BC Proteomics Centre, University of Victoria, Victoria, British Columbia V8Z 7X8, Canada.
authors.forename: Robert W
authors.initials: RW
authors.lastname: Olafson
authors.affiliation: Centre for Forest Biology, Department of Biology, University of Victoria, P.O. Box 3020 Station CSC, Victoria, British Columbia V8W 3N5, Canada.
authors.forename: Patrick
authors.initials: P
authors.lastname: von Aderkas
keywords: conifers; gnetophytes; gymnosperm; mass spectrometry; pollination drop; proteomics