Bacteria growth depends crucially on protein synthesis, which is limited by ribosome synthesis. Ribosomal RNA (rRNA) transcription is the rate-limiting step of ribosome synthesis. It is generally proposed that the transcriptional initiation rate of rRNA operon is the primary factor that controls the rRNA synthesis. In this study, we established a convenient GFP-based reporter approach for measuring the bacterial rRNA chain elongation rate. We showed that the rRNA chain elongation rate of Escherichia coli remains constant under nutrient limitation and chloramphenicol inhibition. In contrast, rR...