ARS | Publication request: Heterologous expression and functional analysis of the wheat group 1 pathogenesis-related (PR-1) proteins

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: May 14, 2012
Publication Date: July 1, 2012
Citation: Dunnell, K.L., Faris, J.D., Friesen, T.L., Edwards, M.C., Lu, S. 2012. Heterologous expression and functional analysis of the wheat group 1 pathogenesis-related (PR-1) proteins. Meeting Abstract. 102:S4.33.

Technical Abstract: The group 1 pathogenesis-related (PR-1) proteins have been widely used as hallmarks of plant defense pathways, but their biological functions are still unknown. We report here the functional analysis of two basic PR-1 proteins following the identification of the wheat PR-1 gene family (Lu et al., 2011). The predicted mature PR-1 proteins were expressed in Pichia pastoris and both targeted proteins were detected in the yeast secretions as a single species of about 15 kDa in SDS-PAGE with a yield estimated at ~ 0.01 mg/ml. Identity of the expressed PR-1 proteins was confirmed by western blot and MALDI-TOF/TOF analyses. No apparent anti-fungal activities were observed in spore germination inhibition assays; both PR-1 proteins, however, appeared to be resistant to proteolytic attack by a bacterial subtilisin-like protease that completely digests several un-related proteins under the same conditions. Reverse transcriptase PCR indicated that both PR-1 transcripts were induced in at least three different wheat lines upon infection by barley stripe mosaic virus (BSMV), a tripartite, (+) sense RNA virus infecting monocot crops, suggesting that the two PR-1 proteins may play a role in basal defense in wheat. Further studies are needed to explore the possibility that PR-1 proteins may function as protease inhibitors or provide protection for other host proteins involved in plant signaling and/or defense pathways.