Bacteria can take up exogenous naked DNA and integrate it into their genomes, which has been regarded as a main contributor to bacterial evolution. The competent status of bacteria is influenced by environmental cues and by the immune systems of bacteria. Here, we review recent advances in understanding the working mechanisms underlying activation of the natural transformation system and limitations thereof. Environmental stresses including the presence of antimicrobials can activate the natural transformation system. However, bacterial enzymes (nucleases), non-coding RNAs, specific DNA sequences, the restriction–modification (R–M) systems, CRISPR-Cas systems and prokaryotic Argonaute proteins (Agos) are have been found to be involved in the limitation of the natural transformation system. Together, this review represents an opportunity to gain insight into bacterial genome stability and evolution.

细菌可以吸收外源裸露的 DNA 并将其整合到它们的基因组中，这被认为是细菌进化的主要贡献者。细菌的能力状态受环境因素和细菌免疫系统的影响。在这里，我们回顾了在理解自然转化系统激活及其局限性的工作机制方面的最新进展。包括抗菌素存在在内的环境压力可以激活自然转化系统。然而，已发现细菌酶（核酸酶）、非编码 RNA、特定 DNA 序列、限制性修饰 (R-M) 系统、CRISPR-Cas 系统和原核 Argonaute 蛋白 (Agos) 与自然转化系统。一起，