Transient increase in salicylic acid and its glucose conjugates after wounding in Arabidopsis leaves

We analyzed metabolic changes after mechanical wounding in Arabidopsis leaves to reveal wound effects on metabolism. Arabidopsis thaliana leaves were wounded by rubbing the leaf surface with silicon carbide particles (carborundum), as for experimental viral infection, and left up to 48 hours. We analyzed the metabolites of five replicate samples at each time point after wounding by ultra performance liquid chromatography time-of-flight mass spectrometry. Jasmonic acid production was induced immediately after wounding, as reported previously. Interestingly, we found that the amount of salicylic acid started to increase significantly 6 hours after wounding, followed by transient increases in salicylic acid glucoside and salicylic acid glucose ester 24 hours after wounding. The expression patterns of genes in salicylic acid biosynthesis pathway, which are available at public transcriptome databases, also support the observation of metabolic changes in salicylic acid and its glucose conjugates. These results indicate activation of salicylic acid metabolism after wounding, suggesting a role of salicylic acid in wound healing. The metabolome data obtained from this study is available from the MassBase metabolome database (http://webs2.kazusa.or.jp/massbase/).