Abstract Detail

Genomics / Proteomics

Urban, Joanna [1], Ross Friedman, Cynthia [1], Kaldenhoff, Ralf [2], Bouditchevskaia, Anastassia [2].

Investigation of gene expression in Arceuthobium spp. during the explosive seed dispersal with special attention to aquaporins.

Arceuthobium americanum (lodgepole pine dwarf mistletoe) is found as a pathogen of coniferous trees across North America, ultimately killing the host tree by redistributing water and nutrients from healthy areas of the tree to those infected with the parasite. Similarly, A. oxycedri (juniper dwarf mistletoe) is detrimental to Juniperus spp. (junipers) in Eurasia. Arceuthobium spp. employ a unique method of seed dispersal whereby the seed is explosively discharged from the fruit. The molecular mechanism of explosive seed discharge and, more specifically, how aquaporins and other proteins could be involved in establishing the hydrostatic pressure responsible for propelling the seed was investigated. Total RNA was extracted from fresh A. americanum as well as from A. oxycedri plants using a MasterPure™ Plant RNA Purification Kit and an RNA Easy Plant Extraction Kit with the addition of PEG, respectively, from samples collected in spring and just before the dispersal of seed (early fall). Extraction was followed by cDNA synthesis and library construction. The cDNA library was screened for aquaporins using MicroHybridization Kit; a Southern Blot was performed with a mixture of Digoxigenin-11-dUTP-labeled probes. Positive results obtained in the hybridization were sent for sequencing. Using NCBI BLAST, sequence similarity to an aquaporin PIP2:1 gene was found. Then, functional studies (stopped flow spectrophotometry) confirmed that the newly-discovered aquaporin is indeed involved in water transport. As Arceuthobium’s genome project has not yet been started and its genome isn’t sequenced, a reverse approach grounded on a heterologous array was used in which RNA from fruits of A. americanum was subjected to commercially available Arabidopsis thaliana Affymetrix gene chip analysis to probe for differences in gene expression before and during explosive seed dispersal.

1 - Thompson Rivers University, Biological Sciences, 900 McGill Rd, Kamloops, BC, V2C 2N6, Canada
2 - Darmstadt Technical University, Institute of Botany, Schnittspahnstrasse 10, Darmstadt, DE, 64237, Germany

Keywords:
Arceuthobium spp
Microarray
seed dispersal
aquaporins
Affymetrix.

Presentation Type: Poster:Posters for Topics
Session: P
Location: Hall D/The Shaw Conference Centre
Date: Monday, July 27th, 2015
Time: 5:45 PM
Number: PGP015
Abstract ID:1315
Candidate for Awards:None