Characterisation of early responses in lead accumulation and localization of Salix babylonica L. roots

Abstract

Background: Lead (Pb) is a harmful pollutant that disrupts normal functions from the cell to organ levels. Salix babylonica is characterized by high biomass productivity, high transpiration rates, and species specific Pb. Better understanding the accumulating and transporting Pb capability in shoots and roots of S. babylonica, the toxic effects of Pb and the subcellular distribution of Pb is very important. Results: Pb exerted inhibitory effects on the roots and shoots growth at all Pb concentrations. According to the results utilizing inductively coupled plasma atomic emission spectrometry (ICP-AES), S. babylonica can be considered as a plant with great phytoextraction potentials as translocation factor (TF) value > 1 is observed in all treatment groups throughout the experiment. The Leadmium™ Green AM dye test results indicated that Pb ions initially entered elongation zone cells and accumulated in this area. Then, ions were gradually accumulated in the meristem zone. After 24 h of Pb exposure, Pb accumulated in the meristem zone. The scanning electron microscopy (SEM) and energy-dispersive X-ray analyses (EDXA) results confirmed the fluorescent probe observations and indicated that Pb was localized to the cell wall and cytoplasm. In transverse sections of the mature zone, Pb levels in the cell wall and cytoplasm of epidermal cells was the lowest compared to cortical and vessel cells, and an increasing trend in Pb content was detected in cortical cells from the epidermis to vascular cylinder. Similar results were shown in the Pb content in the cell wall and cytoplasm of the transverse sections of the meristem. Cell damage in the roots exposed to Pb was detected by propidium iodide (PI) staining, which was in agreement with the findings of Pb absorption in different zones of S. babylonica roots under Pb stress. Conclusion: S. babylonica L. is observed as a plant with great potential of Pb-accumulation and Pb-tolerance. The information obtained here of Pb accumulation and localization in S. babylonica roots can furthers our understanding of Pb-induced toxicity and its tolerance mechanisms, which will provide valuable and scientific information to phytoremediation investigations of other woody plants under Pb stress.

Lead and Copper Removal from Mine Tailings Using Lycium chilense and Haplopappus foliosus

“…The two studied species showed the general behavior of accumulation that most plants do, where higher levels of elements are concentrated in the roots, with poor translocation [16][17][18]. This is observed from the values of BCF and TF for each species and element.…”

“…The uptake of Pb by most plants, close to 90%, is characterized by higher amounts of metal accumulated in the roots and only a small part translocated and accumulated in the plant's aerial parts [16,17]. In the case of Cu, most plants that tolerate the element are excluders, and translocation from the roots to aerial parts is limited [18].…”

De Novo transcriptome combined with physiological analyses revealed key genes for cadmium accumulation in Zhe-Maidong (Ophiopogon japonicus)

“…The tissue blocks were sliced by a frozen section machine (CM1950, Leica, USA) at 10 µm and placed on slides. Detection of Cd 2+ distribution and its fluorescence intensity in developing anthers was performed according to previous studies ( Xue et al., 2020 ). Frozen sections were rinsed with PBS three times before incubating in a Cd 2+ probe (Life Leadmium™ Green AM dye) at 28°C in the dark for 10 min.…”

The potential of Monstera sp. phytoremediation in various lead-contaminated water samples

“…Plant roots swiftly respond, forming a barrier that prevents Pb from entering [36]. Immobilization in cell walls, deposition of insoluble Pb in the intercellular space, accumulation in the plasma membrane, and sequestration in vacuoles all impede Pb transport from roots to shoots [37,38]. Heavy metal uptake by plants, accumulation in roots without interfering with primary functions, and limited translocation to shoots are all thought to contribute to species tolerance to heavy metals [39].…”