Quorum sensing (QS) signals are widely utilized by bacteria to regulate biological functions in response to cell population density. Previous studies have demonstrated that Ralstonia solanacearum employs two different types of QS systems. We report here that anthranilic acid controls important biological functions and the production of QS signals in R. solanacearum. It was demonstrated that the biosynthesis of anthranilic acid is mainly performed by TrpEG. The accumulation of anthranilic acid and the transcription of trpEG occur in a cell density-dependent manner in R. solanacearum. Both the anthranilic acid and TrpEG homologues are conserved in various bacterial species. Moreover, we show that Sporisorium scitamineum sexual mating and hypha formation are strongly inhibited by the addition of exogenous anthranilic acid. Our results suggest that anthranilic acid is important for the physiology of bacteria in addition to its role in inter-kingdom communication.

细菌广泛利用群体感应（QS）信号来调节生物功能以响应细胞群体密度。先前的研究表明，青枯雷尔斯顿菌采用两种不同类型的 QS 系统。我们在此报道，邻氨基苯甲酸控制着青枯菌的重要生物功能和 QS 信号的产生。结果表明，邻氨基苯甲酸的生物合成主要是由TrpEG进行的。在青枯菌中，邻氨基苯甲酸的积累和trpEG的转录以细胞密度依赖性方式发生。邻氨基苯甲酸和TrpEG同系物在各种细菌物种中都是保守的。此外，我们发现添加外源邻氨基苯甲酸会强烈抑制Sporisorium scitamineum的有性交配和菌丝形成。我们的结果表明，邻氨基苯甲酸除了在菌界间通讯中发挥作用外，对细菌的生理学也很重要。