TY - JOUR
T1 - Role of two sets of rnd-type multidrug efflux pump transporter genesmexab-oprm and MEXEF-OPRN, in virulence of pseudomonas syringae pv. Tabaci 6605
AU - Ichinose, Yuki
AU - Nishimura, Takafumi
AU - Harada, Minori
AU - Kashiwagi, Ryota
AU - Yamamoto, Mikihiro
AU - Noutoshi, Yoshiteru
AU - Toyoda, Kazuhiro
AU - Taguchi, Fumiko
AU - Takemoto, Daigo
AU - Matsui, Hidenori
N1 - Funding Information:
We would like to thank the Leaf Tobacco Research Laboratory of Japan Tobacco Inc. for providing Pta 6605. This work was supported in part by JSPS KAKENHI Grant Numbers 16K14861 and 19H02956.
Publisher Copyright:
© The Korean Society of Plant Pathology.
PY - 2020
Y1 - 2020
N2 - Pseudomonas syringae pv. tabaci 6605 has two mul-tidrug resistance (MDR) efflux pump transporters, MexAB-OprM and MexEF-OprN. To understand the role of these MDR efflux pumps in virulence, we generated deletion mutants, ∆mexB, ∆mexF, and ∆mexB∆mexF, and investigated their sensitivity to plant-derived antimicrobial compounds, antibiotics, and virulence. Growth inhibition assays with KB soft agar plate showed that growth of the wild-type (WT) was inhibited by 5 µl of 1 M catechol and 1 M coumarin but not by other plant-derived potential antimicrobial compounds tested including phytoalexins. The sensitivity to these compounds tended to increase in ∆mexB and ∆mexB∆mexF mutants. The ∆mexB∆mexF mutant was also sensitive to 2 M acetovanillone. The mexAB-oprM was constitutively expressed, and activated in the ∆mexF and ∆mexB∆mexF mutant strains. The swarming and swimming motilities were impaired in ∆mexF and ∆mexB∆mexF mutants. The flood inoculation test indicated that bacterial populations in all mutant strains were significantly lower than that of WT, although all mutants and WT caused similar disease symptoms. These results indicate that MexAB-OprM extrudes plant-derived catechol, acetovanillone, or cou-marin, and contributes to bacterial virulence. Further-more, MexAB-OprM and MexEF-OprN complemented each other’s functions to some extent.
AB - Pseudomonas syringae pv. tabaci 6605 has two mul-tidrug resistance (MDR) efflux pump transporters, MexAB-OprM and MexEF-OprN. To understand the role of these MDR efflux pumps in virulence, we generated deletion mutants, ∆mexB, ∆mexF, and ∆mexB∆mexF, and investigated their sensitivity to plant-derived antimicrobial compounds, antibiotics, and virulence. Growth inhibition assays with KB soft agar plate showed that growth of the wild-type (WT) was inhibited by 5 µl of 1 M catechol and 1 M coumarin but not by other plant-derived potential antimicrobial compounds tested including phytoalexins. The sensitivity to these compounds tended to increase in ∆mexB and ∆mexB∆mexF mutants. The ∆mexB∆mexF mutant was also sensitive to 2 M acetovanillone. The mexAB-oprM was constitutively expressed, and activated in the ∆mexF and ∆mexB∆mexF mutant strains. The swarming and swimming motilities were impaired in ∆mexF and ∆mexB∆mexF mutants. The flood inoculation test indicated that bacterial populations in all mutant strains were significantly lower than that of WT, although all mutants and WT caused similar disease symptoms. These results indicate that MexAB-OprM extrudes plant-derived catechol, acetovanillone, or cou-marin, and contributes to bacterial virulence. Further-more, MexAB-OprM and MexEF-OprN complemented each other’s functions to some extent.
KW - Acetovanillone
KW - Catechol
KW - Coumarin
KW - MexAB-OprM
KW - Virulence
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U2 - 10.5423/PPJ.OA.11.2019.0273
DO - 10.5423/PPJ.OA.11.2019.0273
M3 - Article
AN - SCOPUS:85083235824
VL - 36
SP - 148
EP - 156
JO - Plant Pathology Journal
JF - Plant Pathology Journal
SN - 1598-2254
IS - 2
ER -