中文摘要：

微生物能感知环境胁迫信号,通过触发严谨反应对生长速率进行调节,并通过一系列代谢调控,使细胞能在不利环境中生存。高度磷酸化的鸟苷四/五磷酸ppGpp/pppGpp（文中以ppGpp统称）作为信号分子对微生物生理具有广泛的调节作用,至今仍是微生物学研究热点之一。ppGpp对于微生物适应高温、高压等环境起到了积极的作用。综述了信号分子ppGpp合成降解机制及其调控微生物适应性方面的研究进展。

英文摘要：

When microorganism confronted with unfavorable environment,it can perceive the stress signal and start stringent response quickly to make bacteria more adaptive to all kinds of environment.The guanosine tetraphosphate ppGpp is the most celebrated alarmone to trigger the gene regulation for environmental adaptation according to its physiological status in prokaryote.ppGpp plays an active role especially in extreme environment adaptation,i.e.stress response to high temperature,high pressure et al.This paper reviews the mechanism of ppGpp regulation and the recent progress on the causal relationship between ppGpp and various environmental adaptations.