How might a microbial cell that is entirely metabolically dormant – and which has the ability to remain so for extended periods of time – irreversibly commit itself to resuming vegetative growth within seconds of being exposed to certain amino acids or sugars? That this process takes place in the absence of any detectable ATP or de novo protein synthesis, and relies upon a pre-formed apparatus that is immobilised, respectively, in a semi-crystalline membrane or multi-layered proteinaceous coat, only exacerbates the challenge facing spores of Bacillales species when stimulated to germinate. Whereas the process by which spores are formed in response to nutrient starvation – sporulation – involves the orchestrated interplay between hundreds of distinct proteins, the process by which spores return to life – germination – is a much simpler affair, requiring a handful of receptor and channel proteins complemented with specialized peptidoglycan lysins. Despite this relative simplicity, and research effort spanning many decades, comprehensive understanding of key molecular and biochemical details and, in particular signal transduction mechanisms associated with spore germination, has remained elusive. In this review we provide an up to date overview of the field while identifying what we consider to be the key gaps in knowledge associated with germination of Bacillales spores, suggesting also technical approaches that may provide fresh insight to this unique biological process.

一个完全代谢休眠的微生物细胞——并且能够长时间保持这种状态——如何在暴露于某些氨基酸或糖类后几秒钟内不可逆转地恢复营养生长？这一过程发生在没有任何可检测的 ATP 或从头蛋白质合成的情况下，并且依赖于分别固定在半结晶膜或多层蛋白质外壳中的预制装置，只会加剧面临的挑战芽孢杆菌属的孢子受刺激发芽。孢子因营养缺乏而形成的过程 - 孢子形成 - 涉及数百种不同蛋白质之间精心设计的相互作用，而孢子恢复生命的过程 - 发芽 - 是一个简单得多的事情，需要少量受体和通道蛋白，并辅以专门的肽聚糖溶素。尽管这种相对简单，并且研究工作跨越了几十年，但对关键分子和生化细节，特别是与孢子萌发相关的信号转导机制的全面了解仍然难以捉摸。在这篇综述中，我们提供了该领域的最新概述，同时确定了我们认为与芽孢杆菌孢子萌发相关的知识中的关键空白，并提出了可能为这一独特的生物过程提供新见解的技术方法。对关键分子和生化细节的全面了解，特别是与孢子萌发相关的信号转导机制，仍然难以捉摸。在这篇综述中，我们提供了该领域的最新概述，同时确定了我们认为与芽孢杆菌孢子萌发相关的知识中的关键空白，并提出了可能为这一独特的生物过程提供新见解的技术方法。对关键分子和生化细节的全面了解，特别是与孢子萌发相关的信号转导机制，仍然难以捉摸。在这篇综述中，我们提供了该领域的最新概述，同时确定了我们认为与芽孢杆菌孢子萌发相关的知识中的关键空白，并提出了可能为这一独特的生物过程提供新见解的技术方法。