04 × MS [105]) and incubated for 3 to 4 hours. For the measurement of the oxidative burst 200 μl aliquots of these suspensions were mixed with phosphate buffer (50 mM potassium phosphate, pH 7.9) and 1.2 mM luminol in the same phosphate buffer. The reaction was started by the addition of 100 μl of 14 mM potassium hexacyanate. The luminescence was measured

with a Luminometer 1250 (BioOrbit, MI-503 cost Turku, Finland). The intensity of luminescence was calibrated for hydrogen peroxide concentrations of 0.01 mM, to 0.05 mM. Chemicals Cyclosporin A supplier Polygalacturonic acid (sodium salt), pectin and polymyxin B agarose was from Sigma-Aldrich, Taufkirchen, Germany. Unless otherwise specified, other chemicals were obtained from Merck, Darmstadt, Germany. Acknowledgements We gratefully acknowledge Dorothee Steinmann for providing the X. campestris

pv. campestris mutant strain B100-Bac2. Also, we want to thank Dr. Bruno Moerschbacher from the Institut für Biochemie und Biotechnologie in Münster, Germany for the kind permission to use his HPAEC system. At Bielefeld University, the project benefitted from work carried out by, Julia Voß, Sergej Wendler, Anna Köpfer, and Tim Steffens. Jannis Harfmann provided supportive transcriptomics data. Completing the project successfully benefited substantially from oxidative burst measurements carried out by Barbara Samenfeld. This work was financially supported selleck chemicals by the BMBF program “GenoMik Plus”. We acknowledge support of the publication fee by Deutsche Forschungsgemeinschaft and by the Open Access Publication Funds of Bielefeld University. Electronic supplementary material Additional file

1: Multiple alignment of Xanthomonas exbD2 gene products. (PDF 12 KB) Additional file 2: Figure displaying the recovery of extracellular pectate lyase activities in complemented X. campestris pv. campestris strains originally deficient in genes of the TonB system. (PDF 232 KB) Additional file 3: Table S1 with pectate lyase activity in X. campestris pv. campestris and E. coli strains. (PDF 11 KB) Additional file 4: Figure displaying oxidative burst reactions in heterologous N. tabacum cell suspension cultures upon elicitation with supernatants Resveratrol of X. campestris pv. campestris cultures deficient in genes of the TonB system. (PDF 29 KB) Additional file 5: Table S2 with genes of pectin-degrading enzymes in X. campestris pv. campestris B100. (PDF 12 KB) References 1. Jones JD, Dangl JL: The plant immune system. Nature 2006,444(7117):323–329.PubMedCrossRef 2. Boller T, Felix G: A renaissance of elicitors: perception of microbe-associated molecular patterns and danger signals by pattern-recognition receptors. Annu Rev Plant Biol 2009, 60:379–406.PubMedCrossRef 3. Bauer Z, Gomez-Gomez L, Boller T, Felix G: Sensitivity of different ecotypes and mutants of Arabidopsis thaliana toward the bacterial elicitor flagellin correlates with the presence of receptor-binding sites. J Biol Chem 2001,276(49):45669–45676.