Indole is a signalling molecule produced by many bacterial species and involved in intraspecies, interspecies, and interkingdom signalling. Despite the increasing volume of research published in this area, many aspects of indole signalling remain enigmatic. There is disagreement over the mechanism of indole import and export and no clearly defined target through which its effects are exerted. Progress is hindered further by the confused and sometimes contradictory body of indole research literature. We explore the reasons behind this lack of consistency and speculate whether the discovery of a new, pulse mode of indole signalling, together with a move away from the idea of a conventional protein target, might help to overcome these problems and enable the field to move forward.

吲哚是由许多细菌物种产生的信号分子，参与种内、种间和界间信号传导。尽管在这一领域发表的研究数量不断增加，但吲哚信号转导的许多方面仍然是个谜。吲哚的进出口机制存在争议，其作用靶点尚无明确规定。吲哚研究文献的混乱和有时相互矛盾的主体进一步阻碍了进展。我们探讨了这种缺乏一致性背后的原因，并推测新的吲哚信号脉冲模式的发现，以及摆脱传统蛋白质靶点的想法，是否有助于克服这些问题并推动该领域的发展向前。