Multicolor flow cytometry analysis

Bacterial cells were counted on a BD FACSAria Illu (BD Biosciences, USA) flow cytometer, the related technical settings are outlined in “Supplementary materials and methods”, and the gating strategy was adapted from our previous study [63 (link)]. Briefly, a 488 nm excitation laser and the FITC (530/30 nm band-pass filter) detector were used to detect GFP, a 405 nm excitation laser and the DAPI (450/40 nm band-pass filter) detector were used to detect mTagBFP2, and a 561 nm excitation laser and the (PE)-Texas Red (610/20 nm band-pass filter) detector were used to detect mCherry. Data in Fig. 1E were analyzed using FlowJo software (Tree Star Inc., USA).