Gram-negative bacteria are important etiological agents of diseases in agricultural crops. The regulation of virulence of these phytopathogens is frequently mediated by the population density-dependent control mechanism of gene expression, quorum sensing. Thus, the present study aimed to evaluate the potential of endophytic (gram-positive) actinobacteria to inhibit this mechanism in gram-negatives. Isolates belonging to the species Microbacterium...