College of Environmental Science and Engineering, Guilin University of Technology, Guilin, China; Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology, Guilin University of Technology, Guilin, China.
Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang, China.
J Hazard Mater. 2023 Feb 5;443(Pt A):130206. doi: 10.1016/j.jhazmat.2022.130206. Epub 2022 Oct 18.
Understanding the molecular mechanism of tolerance to heavy metals in hyperaccumulators is important for improving the efficiency of phytoremediation and is interesting for evolutionary studies on plant adaption to abiotic stress. Celosia argentea Linn. was recently discovered to hyperaccumulate both manganese (Mn) and cadmium (Cd). However, the molecular mechanisms underlying Mn and Cd detoxification in C. argentea are poorly understood. Laboratory studies were conducted using C. argentea seedlings exposed to 360 μM Mn and 8.9 μM Cd hydroponic solutions. Plant leaves were analyzed using transcriptional and metabolomic techniques. A total of 3960 differentially expressed genes (DEGs) in plants were identified under Cd stress, among which 17 were associated with metal transport, and 10 belonged to the ATP transporter families. Exposures to Mn or Cd led to the differential expression of three metal transport genes (HMA3, ABCC15, and ATPase 4). In addition, 33 and 77 differentially expressed metabolites (DEMs) were identified under Mn and Cd stresses, respectively. Metabolic pathway analysis showed that the ABC transporter pathway was the most affected in Mn/Cd exposed seedlings. Conjoint transcriptome and metabolome analysis showed that the glutathione (GSH) metabolic pathway was over-represented in the KEGG pathway of both DEGs and DEMs. Our results confirm that the ABC transporter and GSH metabolic pathways play important roles in Mn and Cd detoxification. These findings provide new insight into the molecular mechanisms of tolerance to Mn and Cd toxicity in plants.
理解超富集植物耐受重金属的分子机制对于提高植物修复效率具有重要意义，同时对于研究植物适应非生物胁迫的进化也具有重要意义。近年来，发现鸡冠花能够同时超富集锰（Mn）和镉（Cd）。然而，鸡冠花中 Mn 和 Cd 解毒的分子机制仍知之甚少。本研究采用水培实验，用 360 μM Mn 和 8.9 μM Cd 处理鸡冠花幼苗，利用转录组学和代谢组学技术对植物叶片进行分析。结果表明，Cd 胁迫下，鸡冠花中有 3960 个差异表达基因（DEGs），其中 17 个与金属转运有关，10 个属于 ATP 转运蛋白家族。暴露于 Mn 或 Cd 会导致 3 个金属转运基因（HMA3、ABCC15 和 ATPase 4）的差异表达。此外，在 Mn 和 Cd 胁迫下，分别鉴定出 33 个和 77 个差异表达代谢物（DEMs）。代谢途径分析表明，ABC 转运蛋白途径在 Mn/Cd 暴露的幼苗中受影响最大。联合转录组和代谢组分析表明，在 DEGs 和 DEMs 的 KEGG 途径中，谷胱甘肽（GSH）代谢途径被过度表达。研究结果证实，ABC 转运蛋白和 GSH 代谢途径在 Mn 和 Cd 解毒中起重要作用。这些发现为植物耐受 Mn 和 Cd 毒性的分子机制提供了新的见解。
