通过一系列水培实验,研究了锰对青藤吸收Cd的影响机理。结果表明,不同锰处理对木薯吸收Cd的影响不同。Mn预处理在Cd浓度(4和6μM)下增加了根原生质体对Cd的吸收。原生质体在6μMCd和25°C时达到峰值Cd吸收速率,对照组为67.71±0.13μMh-1mL-1,和50μMMn预处理组的77.99±0.49μMh-1mL-1。然而,Cd和Mn的同时处理降低了根原生质体对Cd2的吸收。这种差异可能归因于镉和锰在根细胞中共享一些转运蛋白。根中的转录组分析表明,十个基因(包括ABCC,ABCA,ABCG,ABCB,ABC1,BZIP19和ZIP5)响应于Mn胁迫而显着上调(p<0.05)。这些基因调节属于ABC的转运蛋白的表达,和ZIP家族,这可能与C.argentea根细胞对Cd的吸收有关。Mn预处理上调Mn/Cd转运体的表达,增强根原生质体吸收Cd。对于同时处理Cd和Mn,Cd吸收的抑制是由于相同转运蛋白的竞争。这些发现为理解高积累物中Mn和Cd吸收的机理提供了有益的见解,并为改善C.argentea对Cd污染土壤的植物修复提供了启示。
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-1 mL-1 in the control, and 77.99 ± 0.49 μM h-1 mL-1 in the 50 μM Mn pretreatment group. However, simultaneous treatment with Cd and Mn reduced the Cd2+ 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.