start-ver=1.4 cd-journal=joma no-vol=215 cd-vols= no-issue= article-no= start-page=29 end-page=35 dt-received= dt-revised= dt-accepted= dt-pub-year=2018 dt-pub=201810 dt-online= en-article= kn-article= en-subject= kn-subject= en-title= kn-title=Specific growth inhibitors of Ralstonia solanacearum, Xanthomonas oryzae pv. oryzae, X. campestris pv. campestris, and Clavibacter michiganensis subsp. michiganensis en-subtitle= kn-subtitle= en-abstract= kn-abstract= Plant pathogenic bacteria cause huge yield losses in crops globally. Therefore, finding effective bactericides to these pathogens is an immediate challenge. In this study, we sought compounds that specifically inhibit the growth of Ralstonia solanacearum. As a result, we identified one promising compound, 1-(4-bromophenyl)-6-methoxy-2,3,4,9-tetrahydro-1H-β-carboline, which inhibited the growth of R. solanacearum (Rs1002) from a pilot library of 376 chemicals provided from RIKEN. We further obtained its structural analogues and assessed their ability to inhibit Rs1002 growth. Then we identified five compounds, named ralhibitins A to E, that specifically inhibit growth of Rs1002 at >5 μg/ml final concentration. The most effective compounds, ralhibitins A, C, and E completely inhibited the growth of Rs1002 at 1.25 μg/ml. In addition, ralhibitins A to E inhibited growth of Xanthomonas oryzae pv. oryzae but not the other bacteria tested at a final concentration of 10 μg/ml. Whereas, ralhibitin E, besides inhibiting R. solanacearum and X. oryzae pv. oryzae, completely inhibited the growth of X. campestris pv. campestris and the Gram-positive bacterium Clavibacter michiganensis subsp. michiganensis at 10 μg/ml. Growth inhibition by these compounds was stable at pH 6–9 and after autoclaving. Because Rs1002 grew in the culture medium in which ralhibitins were incubated with the ralhibitin-insensitive bacteria, the unaffected bacteria may be able to inactivate the inhibitory effect of ralhibitins. These results suggest that ralhibitins might be potential lead compounds for the specific control of phytopathogenic bacteria. en-copyright= kn-copyright= en-aut-name= en-aut-sei= en-aut-mei= kn-aut-name=Sing’ombe OmbiroGeofrey kn-aut-sei=Sing’ombe Ombiro kn-aut-mei=Geofrey aut-affil-num=1 ORCID= en-aut-name=SawaiTaku en-aut-sei=Sawai en-aut-mei=Taku kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=2 ORCID= en-aut-name=NoutoshiYoshiteru en-aut-sei=Noutoshi en-aut-mei=Yoshiteru kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=3 ORCID= en-aut-name=NishinaYuta en-aut-sei=Nishina en-aut-mei=Yuta kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=4 ORCID= en-aut-name=MatsuiHidenori en-aut-sei=Matsui en-aut-mei=Hidenori kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=5 ORCID= en-aut-name=YamamotoMikihiro en-aut-sei=Yamamoto en-aut-mei=Mikihiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=6 ORCID= en-aut-name=ToyodaKazuhiro en-aut-sei=Toyoda en-aut-mei=Kazuhiro kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=7 ORCID= en-aut-name=IchinoseYuki en-aut-sei=Ichinose en-aut-mei=Yuki kn-aut-name= kn-aut-sei= kn-aut-mei= aut-affil-num=8 ORCID= affil-num=1 en-affil=Graduate School of Environmental and Life Science, Okayama University kn-affil= affil-num=2 en-affil=Graduate School of Environmental and Life Science, Okayama University kn-affil= affil-num=3 en-affil=Graduate School of Environmental and Life Science, Okayama University kn-affil= affil-num=4 en-affil=Research Core for Interdisciplinary Sciences, Okayama University kn-affil= affil-num=5 en-affil=Graduate School of Environmental and Life Science, Okayama University kn-affil= affil-num=6 en-affil=Graduate School of Environmental and Life Science, Okayama University kn-affil= affil-num=7 en-affil=Graduate School of Environmental and Life Science, Okayama University kn-affil= affil-num=8 en-affil=Graduate School of Environmental and Life Science, Okayama University kn-affil= en-keyword=Bactericide kn-keyword=Bactericide en-keyword=Ralhibitins kn-keyword=Ralhibitins en-keyword=Ralstonia solanacearum kn-keyword=Ralstonia solanacearum en-keyword=Lead compounds kn-keyword=Lead compounds END