High-resolution transcriptional analysis of the regulatory influence of cell-to-cell signalling reveals novel genes that contribute to Xanthomonas phytopathogenesis
Article first published online: 26 APR 2013
© 2013 The Authors. Molecular Microbiology published by John Wiley & Sons Ltd.
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Volume 88, Issue 6, pages 1058–1069, June 2013
How to Cite
An, S.-Q., Febrer, M., McCarthy, Y., Tang, D.-J., Clissold, L., Kaithakottil, G., Swarbreck, D., Tang, J.-L., Rogers, J., Dow, J. M. and Ryan, R. P. (2013), High-resolution transcriptional analysis of the regulatory influence of cell-to-cell signalling reveals novel genes that contribute to Xanthomonas phytopathogenesis. Molecular Microbiology, 88: 1058–1069. doi: 10.1111/mmi.12229
- Issue published online: 10 JUN 2013
- Article first published online: 26 APR 2013
- Manuscript Accepted: 7 APR 2013
- Science Foundation of Ireland. Grant Numbers: SFI 07/IN.1/B955, SFI 09/SIRG/B1654
- Wellcome Trust. Grant Numbers: WT093314MA, WT100204AIA
The bacterium Xanthomonas campestris is an economically important pathogen of many crop species and a model for the study of bacterial phytopathogenesis. In X. campestris, a regulatory system mediated by the signal molecule DSF controls virulence to plants. The synthesis and recognition of the DSF signal depends upon different Rpf proteins. DSF signal generation requires RpfF whereas signal perception and transduction depends upon a system comprising the sensor RpfC and regulator RpfG. Here we have addressed the action and role of Rpf/DSF signalling in phytopathogenesis by high-resolution transcriptional analysis coupled to functional genomics. We detected transcripts for many genes that were unidentified by previous computational analysis of the genome sequence. Novel transcribed regions included intergenic transcripts predicted as coding or non-coding as well as those that were antisense to coding sequences. In total, mutation of rpfF, rpfG and rpfC led to alteration in transcript levels (more than fourfold) of approximately 480 genes. The regulatory influence of RpfF and RpfC demonstrated considerable overlap. Contrary to expectation, the regulatory influence of RpfC and RpfG had limited overlap, indicating complexities of the Rpf signalling system. Importantly, functional analysis revealed over 160 new virulence factors within the group of Rpf-regulated genes.