Smoke-derived seed germination is an important trait for plants to colonize postfire habitats. The well-characterized smoke-derived chemicals of karrikins germinate seeds of species not known to occur after fires in nature. Hence, the ecologically relevant germination cues in smoke remain to be explored for native postfire plants. With the fire-chaser, Nicotiana attenuata, we revisit a bioassay-driven fractionation of liquid smoke to identify ecologically relevant germination cues. By combining bioassay-guided fractionation and comparative unbiased metabolomics, we developed a robust and efficient method to identify germination cues in smoke. Syringaldehyde (SAL) was re-identified as a germination cue in fractions of liquid smoke that promote seed germination. SAL was found to be produced during wildfires in the plant's native habitat, efficiently adsorbed to N. attenuata seeds from aqueous solutions and not readily leached from soil and accurately predicted the boundaries of natural fire events that reflect the occurrence of native postfire N. attenuata populations. We propose that SAL is an ecologically relevant germination cue in smoke for this species.

烟雾衍生的种子发芽是植物在火灾后栖息地定居的重要特征。众所周知，karrikins 的烟雾衍生化学物质会在自然界发生火灾后萌发未知物种的种子。因此，对于本地火灾后植物，烟雾中与生态相关的发芽线索仍有待探索。与追火者，Nicotiana attenuata，我们重新审视了由生物测定驱动的液态烟雾分级，以确定与生态相关的发芽线索。通过结合生物测定指导的分级分离和比较无偏的代谢组学，我们开发了一种可靠且有效的方法来识别烟雾中的发芽线索。丁香醛 (SAL) 被重新识别为促进种子发芽的液体烟雾部分中的发芽线索。SAL 被发现在植物原生栖息地的野火期间产生，有效地从水溶液中吸附到N. attenuata种子上，不易从土壤中浸出，并准确预测自然火灾事件的边界，以反映本地火灾后N. attenuata的发生人口。我们认为 SAL 是该物种在烟雾中的生态相关发芽线索。