College of Earth Sciences, Guilin University of Technology, Guilin, 541004, China; Guangxi Key Laboratory of Exploration for Hidden Metallic Ore Deposits, Guilin, 541004, China.
Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology, Guilin University of Technology, Guilin, 541004, China.
Plant Physiol Biochem. 2024 Sep;214:108925. doi: 10.1016/j.plaphy.2024.108925. Epub 2024 Jul 10.
The effect mechanism of Mn on Cd uptake by Celosia argentea was investigated via a series of hydroponics experiments. The results showed that different manganese treatments had different effects on Cd uptake by C. argentea. Mn pretreatment increased Cd uptake by root protoplasts at Cd concentrations (4 and 6 μM). Protoplasts reached peak Cd uptake rate at 6 μM Cd and 25 °C, with 67.71 ± 0.13 μM h mL in the control, and 77.99 ± 0.49 μM h mL in the 50 μM Mn pretreatment group. However, simultaneous treatment with Cd and Mn reduced the Cd uptake by root protoplasts. This discrepancy may be attributed to the fact that cadmium and manganese share some transporters in root cells. The transcriptome analysis in roots revealed that ten genes (including ABCC, ABCA, ABCG, ABCB, ABC1, BZIP19, and ZIP5) were significantly upregulated in response to Mn stress (p < 0.05). These genes regulate the expression of transporters belonging to the ABC, and ZIP families, which may be involved in Cd uptake by root cells of C. argentea. Mn pretreatment upregulates the expression of Mn/Cd transporters, enhancing Cd uptake by root protoplasts. For the simultaneous treatment of Cd and Mn, inhibition of Cd uptake was due to the competition of the same transporters. These findings provide helpful insights for understanding the mechanism of Mn and Cd uptake in hyperaccumulators and give implications to improve the phytoremediation of Cd-contaminated soil by C. argentea.
采用水培实验研究了锰对青葙（Celosia argentea）吸收镉的影响机制。结果表明，不同锰处理对青葙吸收镉的影响不同。锰预处理在 4 和 6 μM Cd 浓度下增加了根原生质体对 Cd 的吸收。原生质体在 6 μM Cd 和 25℃时达到 Cd 吸收的峰值速率，对照组为 67.71±0.13μM·h·mL-1，50 μM Mn 预处理组为 77.99±0.49μM·h·mL-1。然而，Cd 和 Mn 同时处理会降低根原生质体对 Cd 的吸收。这种差异可能是由于镉和锰在根细胞中共享一些转运体。根的转录组分析表明，10 个基因（包括 ABCC、ABCA、ABCG、ABCB、ABCI、BZIP19 和 ZIP5）对 Mn 胁迫显著上调（p<0.05）。这些基因调节 ABC 和 ZIP 家族转运体的表达，可能参与青葙根细胞对 Cd 的吸收。Mn 预处理上调 Mn/Cd 转运体的表达，增强根原生质体对 Cd 的吸收。对于 Cd 和 Mn 的同时处理，抑制 Cd 吸收是由于相同转运体的竞争。这些发现为理解超富集植物中 Mn 和 Cd 吸收的机制提供了有价值的见解，并对提高青葙修复 Cd 污染土壤的能力具有启示意义。
