College of Life Science, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China.
Jiangsu Vocational College of Agriculture and Forestry, Jurong, 212400, People's Republic of China.
Plant Cell Rep. 2018 Nov;37(11):1485-1497. doi: 10.1007/s00299-018-2318-1. Epub 2018 Jul 12.
Transcriptome analysis of Cd-treated switchgrass roots not only revealed novel switchgrass transcripts and gene structures but also highlighted the indispensable role of HSF/HSP network in switchgrass Cd tolerance. Switchgrass (Panicum virgatum L.), a C4 perennial tall grass, can be used for revegetation of Cd-contaminated soil. In the present study, a comparative transcriptome analysis of Cd-treated switchgrass roots was conducted. The result revealed a total of 462 novel transcripts and refined gene structures of 2337 transcripts. KEGG pathway and Gene Ontology analyses of the differentially expressed genes (DEGs) suggested that activation of redox homeostasis and oxidation-related metabolic processes were the primary response to Cd stress in switchgrass roots. In particular, 21 out of 23 differentially expressed shock transcription factor genes (HSFs), and 22 out of 23 differentially expressed heat shock protein genes (HSPs) had increased expression levels after Cd treatment. Furthermore, over-expressing one HSP-encoding gene in Arabidopsis significantly improved plant Cd tolerance. The result highlighted the activation of the redox homeostasis and the involvement of the HSF/HSP network in re-establishing normal protein conformation and thus cellular homeostasis in switchgrass upon Cd stress. These DEGs, especially those of the HSF/HSP network, could be used as candidate genes for further functional studies toward improved plant Cd tolerance in switchgrass and related species.
转录组分析不仅揭示了 Cd 处理的柳枝稷根系中的新型柳枝稷转录本和基因结构，还强调了 HSF/HSP 网络在柳枝稷 Cd 耐受中的不可或缺作用。柳枝稷（Panicum virgatum L.）是一种 C4 多年生高草，可用于受 Cd 污染土壤的植被恢复。本研究对 Cd 处理的柳枝稷根系进行了比较转录组分析。结果共发现 462 个新的转录本，并对 2337 个转录本的基因结构进行了精细化。差异表达基因（DEGs）的 KEGG 通路和基因本体分析表明，在柳枝稷根系中，氧化还原稳态和氧化相关代谢过程的激活是对 Cd 胁迫的主要响应。特别是在 23 个差异表达的休克转录因子基因（HSFs）和 23 个差异表达的热休克蛋白基因（HSPs）中，有 21 个和 22 个在 Cd 处理后表达水平增加。此外，在拟南芥中过表达一个 HSP 编码基因可显著提高植物对 Cd 的耐受性。结果强调了氧化还原稳态的激活以及 HSF/HSP 网络的参与，在 Cd 胁迫下，柳枝稷重新建立正常蛋白质构象和细胞内稳态。这些 DEGs，特别是 HSF/HSP 网络的基因，可作为候选基因，用于进一步研究提高柳枝稷和相关物种的植物 Cd 耐受能力。
