The clpX gene plays an important role in bacterial attachment, stress tolerance, and virulence in Xanthomonas campestris pv. campestris

  • Hsueh-Hsia Lo
  • Chao-Tsai Liao
  • Chih-En Li
  • Ying-Chuan Chiang
  • Yi-Min HsiaoEmail author
Original Paper


Xanthomonas campestris pv. campestris is a bacterial pathogen and the causal agent of black rot in crucifers. In this study, a clpX mutant was obtained by EZ-Tn5 transposon mutagenesis of the X. campestris pv. campestris. The clpX gene was annotated to encode ClpX, the ATP-binding subunit of ATP-dependent Clp protease. The clpX mutant exhibited reduced bacterial attachment, extracellular enzyme production and virulence. Mutation of clpX also resulted in increased sensitivity to a myriad of stresses, including heat, puromycin, and sodium dodecyl sulfate. These altered phenotypes of the clpX mutant could be restored to wild-type levels by in trans expression of the intact clpX gene. Proteomic analysis revealed that the expression of 211 proteins differed not less than twofold between the wild-type and mutant strains. Cluster of orthologous group analysis revealed that these proteins are mainly involved in metabolism, cell wall biogenesis, chaperone, and signal transduction. The reverse transcription quantitative real-time polymerase chain reaction analysis demonstrated that the expression of genes encoding attachment-related proteins, extracellular enzymes, and virulence-associated proteins was reduced after clpX mutation. The results in this study contribute to the functional understanding of the role of clpX in Xanthomonas for the first time, and extend new insights into the function of clpX in bacteria.


Biofilm formation Environmental adaptation Pathogenicity 



This work was supported by Ministry of Science and Technology of Taiwan (Grants Nos. MOST104-2313-B-166-001-MY3 and MOST107-2313-B-166-001-MY3) to YMH, and Central Taiwan University of Science and Technology (grant No. CTU105-P-15) to HHL.

Supplementary material

203_2019_1772_MOESM1_ESM.xlsx (76 kb)
Supplementary file1 (XLSX 75 kb)


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Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  1. 1.Department of Medical Laboratory Science and BiotechnologyCentral Taiwan University of Science and TechnologyTaichungTaiwan

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