title: The host plant metabolite glucose is the precursor of diffusible signal factor (DSF) family signals in Xanthomonas campestris.
abstract: Plant pathogen Xanthomonas campestris pv. campestris produces cis-11-methyl-2-dodecenoic acid (diffusible signal factor [DSF]) as a cell-cell communication signal to regulate biofilm dispersal and virulence factor production. Previous studies have demonstrated that DSF biosynthesis is dependent on the presence of RpfF, an enoyl-coenzyme A (CoA) hydratase, but the DSF synthetic mechanism and the influence of the host plant on DSF biosynthesis are still not clear. We show here that exogenous addition of host plant juice or ethanol extract to the growth medium of X. campestris pv. campestris could significantly boost DSF family signal production. It was subsequently revealed that X. campestris pv. campestris produces not only DSF but also BDSF (cis-2-dodecenoic acid) and another novel DSF family signal, which was designated DSF-II. BDSF was originally identified in Burkholderia cenocepacia to be involved in regulation of motility, biofilm formation, and virulence in B. cenocepacia. Functional analysis suggested that DSF-II plays a role equal to that of DSF in regulation of biofilm dispersion and virulence factor production in X. campestris pv. campestris. Furthermore, chromatographic separation led to identification of glucose as a specific molecule stimulating DSF family signal biosynthesis in X. campestris pv. campestris. (13)C-labeling experiments demonstrated that glucose acts as a substrate to provide a carbon element for DSF biosynthesis. The results of this study indicate that X. campestris pv. campestris could utilize a common metabolite of the host plant to enhance DSF family signal synthesis and therefore promote virulence.
authors: Institute of Molecular and Cell Biology, Proteos, Singapore, Singapore Guangdong Innovative and Entepreneurial Research Team of Sociomicrobiology Basic Science and Frontier Technology, South China Agricultural University, Guangzhou, China Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, China ydeng@imcb.a-star.edu.sg lianhui@imcb.a-star.edu.sg.
authors: Yinyue
authors: Y
authors: Deng
authors: Chongqing Academy of Chinese Materia Medica, Chongqing, China.
authors: Xiaoling
authors: X
authors: Liu
authors: Institute of Molecular and Cell Biology, Proteos, Singapore, Singapore.
authors: Ji'en
authors: J
authors: Wu
authors: Institute of Molecular and Cell Biology, Proteos, Singapore, Singapore.
authors: Jasmine
authors: J
authors: Lee
authors: Institute of Molecular and Cell Biology, Proteos, Singapore, Singapore Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, China.
authors: Shaohua
authors: S
authors: Chen
authors: Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, China.
authors: Yingying
authors: Y
authors: Cheng
authors: Guangdong Innovative and Entepreneurial Research Team of Sociomicrobiology Basic Science and Frontier Technology, South China Agricultural University, Guangzhou, China.
authors: Chunyan
authors: C
authors: Zhang
authors: Institute of Molecular and Cell Biology, Proteos, Singapore, Singapore Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, China ydeng@imcb.a-star.edu.sg lianhui@imcb.a-star.edu.sg.
authors: Lian-Hui
authors: LH
authors: Zhang
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D018441:Biofilms / Q000254:growth & development*; D029741:Brassica rapa / Q000737:chemistry; D005947:Glucose / Q000378:metabolism*; D060888:Real-Time Polymerase Chain Reaction; D015398:Signal Transduction; D037521:Virulence Factors / Q000235:genetics*; D016959:Xanthomonas campestris / Q000235:genetics / Q000502:physiology*
chemical_list: D001426:Bacterial Proteins; D037521:Virulence Factors; D005947:Glucose