|Comparative transcriptomic analysis of Burkholderia glumae reveals the important role of tepR gene in regulating a multitude of cellular processes|
J. PENG (1), J. H. Ham (1), S. Osti (1), I. K. Barphagha (1). (1) Louisiana State University, Baton Rouge, LA, U.S.A.
<i>Burkholderia glumae</i> causes bacterial panicle blight in rice by producing the phytotoxin, toxoflavin, as a major virulence factor. Production of toxoflavin is negatively regulated by <i>tepR</i>, which encodes a sigma 54-dependent response regulator. In order to gain insights into the comprehensive biological functions of <i>tepR</i>, the genome-wide transcriptional profile dependent on <i>tepR</i> was analyzed through comparative transcriptome analysis between a <i>tepR</i> defective mutant and the wild-type strain, resulting in the identification of 238 differentially expressed genes (DEGs). Gene Ontology (GO) enrichment analysis indicated that genes involved in flagella assembly and stress response were highly enriched in <i>tepR</i> defective strain. Kyoto Encyclopaedia of Genes and Genomes (KEGG) pathway enrichment further revealed that <i>tepR</i> positively regulates the gene cluster encoding a type six secretion system (T6SS) and the genes for a branched-chain amino acid ABC Transporter system, but negatively regulates the genes for thiamine, cysteine and methionine metabolism. As homologues of <i>tepR</i> are found in a number of pathogenic <i>Burkholderia </i>species, the modulation of bacterial behavior through the regulatory action of <i>tepR</i> is likely to be a widely occurring phenomenon in this group of bacterial pathogen.