A proteomics approach to identify proteins differentially expressed in Douglas-fir seedlings infected by Phellinus sulphurascens.
We carried out a comparative proteomic study to explore the molecular mechanisms that underlie the defense response of Douglas-fir (DF, Pseudotsuga menziesii) to laminated root rot, a disease caused by Phellinus sulphurascens. 2-DE was conducted on proteins extracted from roots of laboratory-grown, young DF seedlings inoculated with P. sulphurascens. A total of 1303 proteins was detected in 7 dpi infected and uninfected root samples. Among these 1303 proteins, 277 showed differential expression that was statistically significant (p<0.05). Of these 277 proteins, 74 upregulated and 85 downregulated proteins showed at least a two-fold change from controls. Forty seven upregulated and 23 downregulated proteins were selected to be excised and analyzed using LC-MS/MS followed by peptide matching. Our results indicate that the major proteins differentially expressed in P. sulphurascens-infected DF seedlings include those in the following functional groups: disease/defense (27%), metabolism (16%), transcription factors (11%), signal transduction (10%), secondary metabolism (7%) and energy (4%). A number of additional proteins involved in cell structure (3%) and protein synthesis (3%) were also identified. By providing an initial database of candidate pathogenesis-related proteins for the DF-Phellinus sulphurascens pathosystem the results of this study will enable future detailed investigation of gene expression and function.
Islam
M Aminul
MA
Natural Resources Canada, Canadian Forest Service, Pacific Forestry Centre, 506 West Burnside Road, Victoria, BC, Canada V8Z 1M5.
Sturrock
Rona N
RN
Ekramoddoullah
Abul K M
AK
D001487:Basidiomycota / Q000502:physiology*; D015180:Electrophoresis, Gel, Two-Dimensional; D013058:Mass Spectrometry; D010935:Plant Diseases; D040901:Proteomics; D028224:Pseudotsuga / Q000378:metabolism*; D036226:Seedlings / Q000378:metabolism*