Efflux pump gene expression in Erwinia chrysanthemi is induced by exposure to phenolic acids.
Salicylic acid (SA) is an important signaling molecule in local and systemic plant resistance. Following infection by microbial pathogens and the initial oxidative burst in plants, SA accumulation functions in the amplification of defense gene expression. Production of pathogenesis-related proteins and toxic antimicrobial chemicals serves to protect the plant from infection. Successful microbial pathogens utilize a variety of mechanisms to rid themselves of toxic antimicrobial compounds. Important among these mechanisms are multidrug-resistance pumps that bring about the active efflux of toxic compounds from microbial cells. Here, we show that a combination SA and its precursors, t-cinnamic acid and benzoic acid, can activate expression of specific multidrug efflux pump-encoding genes in the plant pathogen Erwinia chrysanthemi and enhance survival of the bacterium in the presence of model as well as plant-derived antimicrobial chemicals. This ability of plant-pathogenic bacteria to co-opt plant defense-signaling molecules to activate multidrug efflux pumps may have evolved to ensure bacterial survival in susceptible host plants.
Ravirala
Ramani S
RS
Department of Biological Sciences, Center for Biotechnology and Genomics, Texas Tech University, Lubbock 79409, UA.
Barabote
Ravi D
RD
Wheeler
David M
DM
Reverchon
Sylvie
S
Tatum
Ouwatha
O
Malouf
Jeremy
J
Liu
Hui
H
Pritchard
Leighton
L
Hedley
Peter E
PE
Birch
Paul R J
PR
Toth
Ian K
IK
Payton
Paxton
P
San Francisco
Michael J D
MJ
D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D019817:Benzoic Acid / Q000494:pharmacology; D001692:Biological Transport / Q000187:drug effects; D018651:Cichorium intybus / Q000382:microbiology; D002934:Cinnamates / Q000494:pharmacology; D016974:Dickeya chrysanthemi / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D004352:Drug Resistance, Microbial / Q000235:genetics; D018432:Drug Resistance, Multiple / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects; D005798:Genes, Bacterial; D015151:Immunoblotting; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D018515:Plant Leaves / Q000382:microbiology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D020156:Salicylic Acid / Q000494:pharmacology
D001426:Bacterial Proteins; D002934:Cinnamates; D008565:Membrane Proteins; C029010:cinnamic acid; C077168:emrA protein, Bacteria; D019817:Benzoic Acid; D020156:Salicylic Acid