Samad Abdul, Pelletier Gervais, Séguin Armand, Degenhardt Dani, Muench Douglas G, Martineau Christine
Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, Québec City, QC, Canada.
Natural Resources Canada, Canadian Forest Service, Northern Forestry Centre, Edmonton, AB, Canada.
Front Plant Sci. 2022 Apr 27;13:857535. doi: 10.3389/fpls.2022.857535. eCollection 2022.
One of the reclamation objectives for treated oil sands tailings (OST) is to establish boreal forest communities that can integrate with the surrounding area. Hence, selection of appropriate soil reclamation cover designs and plant species for revegetation are important aspects of tailings landform reclamation and closure. Research and monitoring of the long term and immediate impacts of capped OST on the growth and survival of native boreal plant species are currently underway. However, plant responses to OST-associated toxicity are not well known at the molecular level. Using RNA sequencing, we examined the effects of three types of OST on the willow transcriptome under different capping strategies. The transcriptomic data showed that some genes respond universally and others in a specific manner to different types of OST. Among the dominant and shared upregulated genes, we found some encoding protein detoxification (PD), Cytochrome P450 (CYPs), glutathione S-transferase regulatory process (GST), UDP-glycosyltransferase (UGT), and ABC transporter and regulatory process associated proteins. Moreover, genes encoding several stress-responsive transcription factors (bZIP, BHLH, ERF, MYB, NAC, WRKY) were upregulated with OST-exposure, while high numbers of transcripts related to photosynthetic activity and chloroplast structure and function were downregulated. Overall, the expression of 40 genes was found consistent across all tailings types and capping strategies. The qPCR analysis of a subset of these shared genes suggested that they could reliably distinguish plants exposed to different OST associated stress. Our results indicated that it is possible to develop OST stress exposure biosensors merely based on changes in the level of expression of a relatively small set of genes. The outcomes of this study will further guide optimization of OST capping and revegetation technology by using knowledge based plant stress adaptation strategies.
处理后的油砂尾矿（OST）的复垦目标之一是建立能够与周边地区融合的北方森林群落。因此，选择合适的土壤复垦覆盖设计和用于植被恢复的植物物种是尾矿地貌复垦和封闭的重要方面。目前正在对覆盖后的OST对北方本土植物物种生长和存活的长期及直接影响进行研究和监测。然而，植物对与OST相关的毒性在分子水平上的反应尚不清楚。我们使用RNA测序技术，研究了三种类型的OST在不同覆盖策略下对柳树转录组的影响。转录组数据表明，一些基因对不同类型的OST有普遍反应，而另一些则有特定反应。在占主导地位且共同上调的基因中，我们发现一些编码蛋白质解毒（PD）、细胞色素P450（CYPs）、谷胱甘肽S-转移酶调节过程（GST）、UDP-糖基转移酶（UGT）以及ABC转运蛋白和调节过程相关蛋白的基因。此外，编码几种应激反应转录因子（bZIP、BHLH、ERF、MYB、NAC、WRKY）的基因在暴露于OST时上调，而大量与光合作用活性以及叶绿体结构和功能相关的转录本则下调。总体而言，发现40个基因的表达在所有尾矿类型和覆盖策略中都是一致的。对这些共享基因的一个子集进行qPCR分析表明，它们能够可靠地区分暴露于不同OST相关胁迫的植物。我们的结果表明，仅基于相对少量基因表达水平的变化就有可能开发出OST胁迫暴露生物传感器。本研究的结果将通过基于知识的植物应激适应策略进一步指导OST覆盖和植被恢复技术的优化。
