Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), Collaborative Innovation Center for Mountain Ecology & Agro-Bioengineering (CICMEAB), College of Life Sciences/Institute of Agro-Bioengineering, Guizhou University, Guiyang 550025, China.
Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China.
Int J Mol Sci. 2023 Jul 29;24(15):12157. doi: 10.3390/ijms241512157.
Cadmium (Cd) is one of the most toxic metals in the environment and exerts deleterious effects on plant growth and production. Duckweed has been reported as a promising candidate for Cd phytoremediation. In this study, the growth, Cd enrichment, and antioxidant enzyme activity of duckweed were investigated. We found that both high-Cd-tolerance duckweed (HCD) and low-Cd-tolerance duckweed (LCD) strains exposed to Cd were hyper-enriched with Cd. To further explore the underlying molecular mechanisms, a genome-wide transcriptome analysis was performed. The results showed that the growth rate, chlorophyll content, and antioxidant enzyme activities of duckweed were significantly affected by Cd stress and differed between the two strains. In the genome-wide transcriptome analysis, the RNA-seq library generated 544,347,670 clean reads, and 1608 and 2045 differentially expressed genes were identified between HCD and LCD, respectively. The antioxidant system was significantly expressed during ribosomal biosynthesis in HCD but not in LCD. Fatty acid metabolism and ethanol production were significantly increased in LCD. Alpha-linolenic acid metabolism likely plays an important role in Cd detoxification in duckweed. These findings contribute to the understanding of Cd tolerance mechanisms in hyperaccumulator plants and lay the foundation for future phytoremediation studies.
镉 (Cd) 是环境中最具毒性的金属之一，对植物的生长和产量产生有害影响。浮萍已被报道为 Cd 植物修复的有前途的候选物。在这项研究中，研究了浮萍的生长、Cd 富集和抗氧化酶活性。我们发现，暴露于 Cd 的高 Cd 耐受性浮萍 (HCD) 和低 Cd 耐受性浮萍 (LCD) 菌株都对 Cd 进行了超富集。为了进一步探讨潜在的分子机制，进行了全基因组转录组分析。结果表明，Cd 胁迫显著影响浮萍的生长速度、叶绿素含量和抗氧化酶活性，并且在两种菌株之间存在差异。在全基因组转录组分析中，RNA-seq 文库生成了 544,347,670 条清洁读取序列，HCD 和 LCD 之间分别鉴定出 1608 和 2045 个差异表达基因。在 HCD 中，核糖体生物合成过程中抗氧化系统显著表达，而在 LCD 中则没有。脂肪酸代谢和乙醇生产在 LCD 中显著增加。α-亚麻酸代谢可能在浮萍的 Cd 解毒中起重要作用。这些发现有助于理解超积累植物的 Cd 耐受机制，并为未来的植物修复研究奠定基础。
