Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology, Guilin University of Technology, Guilin, 541004, China.
Technical Innovation Center of Mine Geological Environmental Restoration Engineering in Southern Karst Area, MNR, Guilin, 541004, China.
Environ Sci Pollut Res Int. 2022 Jun;29(29):44413-44421. doi: 10.1007/s11356-021-17352-2. Epub 2022 Feb 8.
In order to study the mechanism of cadmium (Cd) uptake by the roots of Celosia argentea Linn. (Amaranthaceae), the effects of various inhibitors, ion channel blockers, and hydroponic conditions on Cd fluxes in the roots were characterized using non-invasive micro-test technology (NMT). The net Cd flux (72.5 pmol∙cm∙s) in roots that had been pretreated with Mn was significantly higher than that in non-pretreated roots (58.1 pmol∙cm∙s), indicating that Mn pretreatment enhanced Cd uptake by the roots. This finding may be explained by the fact that the addition of Mn significantly increased the expression of the transporter gene and thus promoted Cd uptake and transport. In addition, Mn pretreatment resulted in an increase in root growth, which may in turn promote root vigor. The uncoupler 2,4-dinitrophenol (DNP) caused a significant reduction in net Cd fluxes in the roots, by 70.5% and 41.4% when exposed to Mn and Cd stress, respectively. In contrast, a P-type ATPase inhibitor (NaVO) had only a small effect on net Cd fluxes to the plant roots, indicating that ATP has a relatively minor role in Cd uptake by roots. La (a Ca channel inhibitor) had a more significant inhibitory effect on net Cd fluxes than did TEA (a K channel inhibitor). Therefore, Cd uptake by plant roots may occur mainly through Ca channels rather than K channels. In summary, uptake of Cd by the roots of C. argentea appears to occur via several types of ion channels, and Mn can promote Cd uptake.
为了研究镉（Cd）被鸡冠花（苋科）根部吸收的机制，采用非侵入性微测技术（NMT）研究了各种抑制剂、离子通道阻断剂和水培条件对根部 Cd 通量的影响。Mn 预处理后的根部净 Cd 通量（72.5 pmol·cm·s）明显高于未经预处理的根部（58.1 pmol·cm·s），表明 Mn 预处理增强了根部对 Cd 的吸收。这一发现可能是由于添加 Mn 显著增加了转运体基因的表达，从而促进了 Cd 的吸收和转运。此外，Mn 预处理导致根生长增加，这可能反过来促进根活力。解偶联剂 2,4-二硝基苯酚（DNP）导致 Mn 和 Cd 胁迫下根部净 Cd 通量分别显著减少 70.5%和 41.4%。相比之下，P 型 ATP 酶抑制剂（NaVO）对植物根部净 Cd 通量的影响较小，表明 ATP 在根部吸收 Cd 中的作用相对较小。La（一种 Ca 通道抑制剂）对净 Cd 通量的抑制作用比 TEA（一种 K 通道抑制剂）更为显著。因此，植物根部对 Cd 的吸收可能主要通过 Ca 通道而不是 K 通道发生。总之，鸡冠花根部的 Cd 吸收似乎通过几种类型的离子通道发生，并且 Mn 可以促进 Cd 的吸收。
