Bacterial strains and plasmids used in this study.

aAp = ampicillin; Km = kanamycin; Sm = streptomycin; Tc = tetracycline; Cm = chloramphenicol; and the superscript r = resistant. Bacterial strains and plasmids used in this study.aAp 代表氨苄青霉素（ampicillin）；Km 代表卡那霉素（kanamycin）；Sm 代表链霉素（streptomycin）；Tc 代表四环素（tetracycline）；Cm 代表氯霉素（chloramphenicol）；上标r代表抗性（resistant）。本研究所用细菌菌株与质粒。