Submitted to: Biochemical and Biophysical Research Communications
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/15/2005
Publication Date: 2/15/2005
Citation: Baker, C.J., Mock, N.M., Whitaker, B.D., Roberts, D.P., Rice, C., Deahl, K.L., Averyanov, A.A. 2005. Involvement of Acetosyringone in plant/pathogen recognition. Biochemical and Biophysical Research Communications. 328:130-136. Interpretive Summary: The goal of this project is to gain new insight into plant/pathogen interactions in order to develop new ways to improve disease resistance in crops. Here we report that chemicals called antioxidants are formed in plant cell walls when plants are infected with bacterial pathogens. We identified of one of these antioxidants to be acetosyringone. We demonstrated that acetosyringone regulates plant/pathogen interactions. This report demonstrates that antioxidants, which protect plants against stresses, may also have important regulatory properties. This work will benefit scientists and farmers by providing new knowledge about plant/pathogen interactions and help further investigations leading to improved crop disease resistance.
Technical Abstract: Acetosyringone was identified as one of the major extracellular phenolics in tobacco cell suspensions and was shown to have bioactive properties that can influence early events in plant bacterial pathogensis. In our model system, tobacco cell suspensions treated with bacterial isolate Pseudomonas syringae WT (HR+) undergo a resistant interaction characterized by a burst in oxygen consumption that starts 4-6 h after inoculation. When the extracellular concentration of acetosyringone was augmented with exogenous acetosyringone, the burst in oxygen consumption occurred as much as 1.5 h earlier. The acetosyringone had no effect on tobacco cell suspensions undergoing susceptible interactions or a non-resistant interaction with a near-isogenic mutant derivative of isolate P. syringae WT (HR+). The extracellular concentration of acetosyringone in tobacco cell suspensions increased as the concentration of the bacterial inoculum increased. This may be a factor in the earlier oxygen uptake response observed in resistant interactions when the inoculum concentration is increased.