Previous studies on the intricate interactions between plants and microorganisms have revealed that fungal volatile compounds (VCs) can affect plant growth and development. However, the precise mechanisms underlying these actions remain to be delineated. In this study, we discovered that VCs from the soilborne fungus Tolypocladium inflatum GT22 enhance the growth of Arabidopsis. Remarkably, priming Arabidopsis with GT22 VCs caused the plant to display an enhanced immune response and mitigated the detrimental effects of both pathogenic infections and copper stress. Transcriptomic analyses of Arabidopsis seedlings treated with GT22 VCs for 3, 24 and 48 h revealed that 90, 83 and 137 genes were differentially expressed, respectively. The responsive genes are known to be involved in growth, hormone regulation, defense mechanisms and signaling pathways. Furthermore, we observed the induction of genes related to innate immunity, hypoxia, salicylic acid biosynthesis and camalexin biosynthesis by GT22 VCs. Among the VCs emitted by GT22, exposure of Arabidopsis seedlings to limonene promoted plant growth and attenuated copper stress. Thus, limonene appears to be a key mediator of the interaction between GT22 and plants. Overall, our findings provide evidence that fungal VCs can promote plant growth and enhance both biotic and abiotic tolerance. As such, our study suggests that exposure of seedlings to T. inflatum GT22 VCs may be a means of improving crop productivity. This study describes a beneficial interaction between T. inflatun GT22 and Arabidopsis. Our investigation of microorganism function in terms of VC activities allowed us to overcome the limitations of traditional microbial application methods. The importance of this study lies in the discovery of T. inflatun GT22 as a beneficial microorganism. This soilborne fungus emits VCs with plant growth–promoting effects and the ability to alleviate both copper and pathogenic stress. Furthermore, our study offers a valuable approach to tracking the activities of fungal VC components via transcriptomic analysis and sheds light on the mechanisms through which VCs promote plant growth and induce resistance. This research significantly advances our knowledge of VC applications and provides an example for further investigations within this field.

中文翻译：

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植物生长促进真菌 Tolypocladium inflatum GT22 释放的挥发性化合物可缓解铜和病原体胁迫

先前对植物和微生物之间复杂相互作用的研究表明，真菌挥发性化合物（VC）可以影响植物的生长和发育。然而，这些行为背后的确切机制仍有待描述。在这项研究中，我们发现来自土传真菌 Tolypocladium inflatum GT22 的 VC 可以促进拟南芥的生长。值得注意的是，用 GT22 VC 引发拟南芥可以使植物表现出增强的免疫反应，并减轻病原体感染和铜胁迫的有害影响。用 GT22 VC 处理 3、24 和 48 小时的拟南芥幼苗的转录组分析显示，分别有 90、83 和 137 个基因出现差异表达。已知反应基因参与生长、激素调节、防御机制和信号传导途径。此外，我们观察到GT22 VC诱导与先天免疫、缺氧、水杨酸生物合成和camalexin生物合成相关的基因。在 GT22 排放的 VC 中，拟南芥幼苗接触柠檬烯可促进植物生长并减轻铜胁迫。因此，柠檬烯似乎是 GT22 与植物之间相互作用的关键介质。总的来说，我们的研究结果证明真菌维生素C可以促进植物生长并增强生物和非生物耐受性。因此，我们的研究表明，将幼苗暴露于 T. inflatum GT22 VC 可能是提高作物生产力的一种手段。这项研究描述了 T. inflatun GT22 和拟南芥之间的有益相互作用。我们对 VC 活性方面​​微生物功能的研究使我们能够克服传统微生物应用方法的局限性。这项研究的重要性在于发现了 T. inflatun GT22 作为一种有益微生物。这种土生真菌释放的维生素C具有促进植物生长的作用，并且能够减轻铜和病原应激。此外，我们的研究提供了一种通过转录组分析追踪真菌 VC 成分活性的有价值的方法，并揭示了 VC 促进植物生长和诱导抗性的机制。这项研究极大地提高了我们对风险投资应用的了解，并为该领域的进一步研究提供了一个例子。