Horizontal gene transfer(HGT)has been well documented as a driving force in the evolution of bacteria.It has been shown that a horizontally acquired gene,xoc_2868,involved in the global response against oxidative stre...Horizontal gene transfer(HGT)has been well documented as a driving force in the evolution of bacteria.It has been shown that a horizontally acquired gene,xoc_2868,involved in the global response against oxidative stress and pathogenicity of Xanthomonas oryzae pv.oryzicola strain BLS256.However,as a transcriptional factor(TF),the regulatory mechanism of XOC_2868 has not yet been revealed.Here,evolutionary analysis suggested XOC_2868 might be co-transferred with its physically proximate downstream genes from a Burkholderiaceae ancestor.Interestingly,RNA-seq data of wild-type(BLS256)andΔxoc_2868 strains under oxidative stress showed that XOC_2868 did not regulate the expression of its adjacent genes,but remarkably influenced the expression of several genes involved in the extracellular polysaccharide(EPS)production and xanthan biosynthesis.Chromatin immunoprecipitation-sequence(ChIP-seq)combined with transcriptome analysis revealed that XOC_2868 directly regulates a cydAB operon,encoding two subunits of cytochrome bd oxidase and involved in redox balance.Consistent withΔxoc_2868 strain,cydA-and cydAB-knockout mutants also showed a higher sensitivity to H_(2)O_(2)along with a reduced bacterial virulence compared with the wild-type strain.Overall,our findings raise the possibility of regulatory circuit evolution shaped by HGT and driven by selection and reveal a novel regulatory pathway that regulates the expression of cytochrome bd oxidase and thus contributes to the virulence of BLS256.展开更多
Horizontal gene transfer(HGT)has been proved a major driving force in prokaryotic evolution.However,the molecular functions of these transferred genes in pathogenic bacteria especially plant pathogenic bacteria are st...Horizontal gene transfer(HGT)has been proved a major driving force in prokaryotic evolution.However,the molecular functions of these transferred genes in pathogenic bacteria especially plant pathogenic bacteria are still not fully investigated.In this study,the whole-genome in silico analysis was performed and found a syringopeptin synthetase(syp)homolog in Burkholderia glumae,which can cause bacterial panicle blight in rice,was predicted to be horizontally transferred from Pseudomonas ancestor with solid confidence by phylogenetic analysis.The comprehensive molecular experiments were performed to study the potential role of this gene in B.glumae.Inoculation of rice panicles with the syp mutant resulted in 60%lower disease index compared with the wild type(WT)parent strain,suggesting the requirement of syp for the full virulence of B.glumae.Chromatography analysis of exudates from B.glumae showed suppression of synthesis of metabolites analogous to syringopeptin in the mutants.All these data raise the possibility of HGT phenomenon in shaping the virulence and adaptation of B.glumae over evolutionary time.展开更多
基金supported by the National Key R&D Program of China (2018YFD0201202 and 2017YFD0201108)the Agri-X Interdisciplinary Fund of Shanghai Jiao Tong University, China (Agri-X2017010)+1 种基金the Shanghai Committee of Science and Technology, China (19390743300)the National Natural Science Foundation of China (31200003)
文摘Horizontal gene transfer(HGT)has been well documented as a driving force in the evolution of bacteria.It has been shown that a horizontally acquired gene,xoc_2868,involved in the global response against oxidative stress and pathogenicity of Xanthomonas oryzae pv.oryzicola strain BLS256.However,as a transcriptional factor(TF),the regulatory mechanism of XOC_2868 has not yet been revealed.Here,evolutionary analysis suggested XOC_2868 might be co-transferred with its physically proximate downstream genes from a Burkholderiaceae ancestor.Interestingly,RNA-seq data of wild-type(BLS256)andΔxoc_2868 strains under oxidative stress showed that XOC_2868 did not regulate the expression of its adjacent genes,but remarkably influenced the expression of several genes involved in the extracellular polysaccharide(EPS)production and xanthan biosynthesis.Chromatin immunoprecipitation-sequence(ChIP-seq)combined with transcriptome analysis revealed that XOC_2868 directly regulates a cydAB operon,encoding two subunits of cytochrome bd oxidase and involved in redox balance.Consistent withΔxoc_2868 strain,cydA-and cydAB-knockout mutants also showed a higher sensitivity to H_(2)O_(2)along with a reduced bacterial virulence compared with the wild-type strain.Overall,our findings raise the possibility of regulatory circuit evolution shaped by HGT and driven by selection and reveal a novel regulatory pathway that regulates the expression of cytochrome bd oxidase and thus contributes to the virulence of BLS256.
基金the National Key R&D Program of China(2018YFD0201202 and 2017YFD0201108)the Agri-X Interdisciplinary Fund of Shanghai Jiao Tong University,China(Agri-X2017010)+3 种基金the State Key Laboratory for Biology of Plant Diseases and Insect Pests of Shanghai Jiao Tong University(SKLOF201802)the Shanghai Committee of Science and Technology(19390743300)the National Natural Science Foundation of China(31200003 and 31770772)Joint Research Funds for Translational Medicine at Shanghai Jiao Tong University(ZH2018ZDA06).
文摘Horizontal gene transfer(HGT)has been proved a major driving force in prokaryotic evolution.However,the molecular functions of these transferred genes in pathogenic bacteria especially plant pathogenic bacteria are still not fully investigated.In this study,the whole-genome in silico analysis was performed and found a syringopeptin synthetase(syp)homolog in Burkholderia glumae,which can cause bacterial panicle blight in rice,was predicted to be horizontally transferred from Pseudomonas ancestor with solid confidence by phylogenetic analysis.The comprehensive molecular experiments were performed to study the potential role of this gene in B.glumae.Inoculation of rice panicles with the syp mutant resulted in 60%lower disease index compared with the wild type(WT)parent strain,suggesting the requirement of syp for the full virulence of B.glumae.Chromatography analysis of exudates from B.glumae showed suppression of synthesis of metabolites analogous to syringopeptin in the mutants.All these data raise the possibility of HGT phenomenon in shaping the virulence and adaptation of B.glumae over evolutionary time.
