The synthesis of virulence factors in the plant pathogen Xanthomonas campestris pathovar campestris is regulated by cell-cell signaling mediated by a diffusible signal factor (DSF), and by the RpfC/RpfG two-component regulatory system. Recent findings have indicated that the perception of the DSF signal requires the RpfC sensor and is linked to the degradation of the intracellular second messenger cyclic di-GMP by the HD-GYP domain regulator RpfG.
Fouhy, Y., Lucey, J. F., Ryan, R. P., Dow, J. M., & Dow, J. M. (2006). Cell-cell signaling, cyclic di-GMP turnover and regulation of virulence in Xanthomonas campestris. Research in Microbiology, 157(10), 899-904. https://doi.org/10.1016/j.resmic.2006.08.001