Wu, D.D.WuRoepenack-Lahaye, E. vonE. vonRoepenack-LahayeBuntru, M.M.BuntruLange, O. deO. deLangeSchandry, N.N.SchandryPérez-Quintero, A.L.A.L.Pérez-QuinteroWeinberg, Z.Z.WeinbergLowe-Power, T.M.T.M.Lowe-PowerSzurek, B.B.SzurekMichael, A.J.A.J.MichaelAllen, C.C.AllenSchillberg, S.S.SchillbergLahaye, T.T.Lahaye2022-03-062022-03-062019https://publica.fraunhofer.de/handle/publica/26745710.1016/j.chom.2019.09.0142-s2.0-85074421624Pathogenic bacteria inject effector proteins into host cells to manipulate cellular processes and facilitate the infection. Transcription-activator-like effectors (TALEs), an effector class in plant pathogenic bacteria, transcriptionally activate host genes to promote disease. We identify arginine decarboxylase (ADC) genes as the host targets of Brg11, a TALE-like effector from the plant pathogen Ralstonia solanacearum. Brg11 targets a 17-bp sequence that was found to be part of a conserved 50-bp motif, termed the ADC-box, upstream of ADC genes involved in polyamine biosynthesis. The transcribed ADC-box attenuates translation from native ADC mRNAs; however, Brg11 induces truncated ADC mRNAs lacking the ADC-box, thus bypassing this translational control. As a result, Brg11 induces elevated polyamine levels that trigger a defense reaction and likely inhibits bacterial niche competitors but not R. solanacearum. Our findings suggest that Brg11 may give R. solanacearum a competitive advantage and uncover a role for bacterial effectors in regulating ternary microbe-host-microbe interactions.en540579571572journal article