In this study, we describe the results obtained in a study of the transgenerational phenotypic effects of chromium (Cr) stress on the model plant species Arabidopsis thaliana. The F1 generation derived from parents grown under chronic and medium chronic stress showed significantly higher levels of the maximal effective concentration (EC₅₀) compared with F1 plants generated from unstressed parents. Moreover, F1 plants from Cr-stressed parents showed a higher germination rate when grown in the presence of Cr. F1 plants derived from parents cultivated under chronic Cr stress displayed reduced hydrogen peroxide levels under Cr stress compared to controls. At lower Cr stress levels, F1 plants were observed to activate promptly more genes involved in Cr stress responses than F0 plants, implying a memory effect linked to transgenerational priming. At higher Cr levels, and at later stages, F1 plants modulated significantly fewer genes than F0 plants, implying a memory effect leading to Cr stress adaptation. Several bHLH transcription factors were induced by Cr stress in F1 but not in F0 plants, including bHLH100, ORG2 and ORG3. F1 plants optimized gene expression towards pathways linked to iron starvation response. A model of the transcriptional regulation of transgenerational memory to Cr stress is presented here, and could be applied for other heavy metal stresses.

在这项研究中，我们描述了铬 (Cr) 胁迫对模式植物拟南芥的跨代表型影响的研究中获得的结果。来自在慢性和中等慢性应激下生长的父母的F1代显示出显着更高水平的最大有效浓度（EC ₅₀) 与未受胁迫的亲本产生的 F1 植物相比。此外，来自 Cr 胁迫亲本的 F1 植物在 Cr 存在下生长时表现出更高的发芽率。与对照相比，来自在慢性 Cr 胁迫下培养的亲本的 F1 植物在 Cr 胁迫下的过氧化氢水平降低。在较低的 Cr 胁迫水平下，观察到 F1 植物比 F0 植物迅速激活更多参与 Cr 胁迫反应的基因，这意味着与跨代启动有关的记忆效应。在较高的 Cr 水平和后期，F1 植物调节的基因明显少于 F0 植物，这意味着记忆效应导致 Cr 胁迫适应。几种bHLH转录因子在 F1 中由 Cr 胁迫诱导，但在 F0 植物中没有，包括bHLH100，ORG2和ORG3。F1 植物优化了与铁饥饿反应相关的途径的基因表达。本文介绍了跨代记忆对 Cr 胁迫的转录调控模型，该模型可应用于其他重金属胁迫。