Global warming has become a critical challenge to food security, causing severe yield losses of major crops worldwide. Conventional and transgenic breeding strategies to enhance plant thermotolerance are laborious and expensive. Therefore, the use of beneficial microbes could be an alternative approach. Here, we report that the root endophyte Enterobacter sp. SA187 induces thermotolerance in wheat in the laboratory as well as in open‐field agriculture. To unravel the molecular mechanisms, we used Arabidopsis thaliana as model plant. SA187 reprogramed the Arabidopsis transcriptome via HSFA2‐dependent enhancement of H3K4me3 levels at heat stress memory gene loci. Unlike thermopriming, SA187‐induced thermotolerance is mediated by ethylene signaling via the transcription factor EIN3. In contrast to the transient chromatin modification by thermopriming, SA187 induces constitutive H3K4me3 modification of heat stress memory genes, generating robust thermotolerance in plants. Importantly, microbial community composition of wheat plants in open‐field agriculture is not influenced by SA187, indicating that beneficial microbes can be a powerful tool to enhance thermotolerance of crops in a sustainable manner.

中文翻译：

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根内生菌通过热应激记忆基因位点的组成型染色质修饰诱导植物耐热性

全球变暖已成为对粮食安全的重大挑战，导致全球主要农作物严重减产。提高植物耐热性的常规和转基因育种策略既费力又昂贵。因此，使用有益微生物可能是一种替代方法。在这里，我们报告了根内生菌肠杆菌属。SA187 在实验室和露天农业中诱导小麦的耐热性。为了阐明分子机制，我们使用拟南芥作为模型植物。SA187 通过HSFA2重编程拟南芥转录组热应激记忆基因位点 H3K4me3 水平的依赖性增强。与热启动不同，SA187 诱导的耐热性是由乙烯信号通过转录因子EIN3介导的。与通过热引发的瞬时染色质修饰相反，SA187 诱导热应激记忆基因的组成型 H3K4me3 修饰，从而在植物中产生强大的耐热性。重要的是，露天农业中小麦植物的微生物群落组成不受 SA187 的影响，这表明有益微生物可以成为以可持续方式增强作物耐热性的有力工具。