*4.3.1 The heavy metal accumulation in vegetative organs*

The increase in cadmium concentration that was added to the MS medium caused a significant increase in cadmium accumulation in the vegetative parts of the *L. camara* plant after 4 weeks of cultivating (**Table 3**) [27]. The 0.8 mg L−1 cadmium was significantly greatest than other treatments (0.192 mg kg−1 cadmium). This finding is in accord with the findings acquired by Kališová-Špirochová et al. [16], who investigated cadmium assembly in *Helianthus annuus*, *Populus tremula × tremuloides*, and *Zea mays*, and Milusheva et al.'s [19] investigation on *Petunia × hybrida* and *Ageratum houstonianum via* tissue culture technique. The findings also agree with the findings acquired by [32] when investigating the phytoremediation possibilities of the *Brassica juncea (L.) Czern*., where an accumulation in cadmium concentration in the vegetative parts was noticed when the added concentration enhanced.

Parallel to cadmium, the assemblage of cobalt in the vegetative parts raised significantly with the enhancement of its concentration in the MS medium after

*The Efficiency of Phytoremediation of the Big-Sage Plant in Accumulating Some Heavy Metals… DOI: http://dx.doi.org/10.5772/intechopen.109640*


**Table 3.**

In vitro *accumulation of cadmium, cobalt, and lead in the vegetative organs of the* Lantana camara *shrub [27].*

4 weeks of cultivating (**Table 3**). The 0.8 mg L−1 cobalt registered the most increased cobalt accumulation among the examined concentrations reaching 0.326 mg kg−1. No indications of toxicity were detected in the plants, which show that the *L. camara* is a phytoremediator that accumulates heavy metals without impacting its growth. These findings were alike to Al-Wahaibi's [33] findings, which indicated that assembling heavy metals in these plants is a natural direction for them.

Regarding lead accumulation, there was no lead assemblage in the vegetative parts in any the examined concentrations (**Table 3**). Comparable findings were registered in other plant species where lead assemblies were in the root parts instead of the vegetative parts [34].

### *4.3.2 Heavy metal accumulation in the root organs*

Cadmium and cobalt concentrations of roots significantly accumulated with each rising in cadmium and cobalt concentrations in the MS medium (**Table 4**). The treatment of 0.8 mg L−1 concentration of cadmium or cobalt caused the highest metal accumulation reaching 0.318 mg kg−1 cadmium and 0.312 mg kg−1 cobalt.

Furthermore, lead assembled in root parts was noticed under 0.6 and 0.8 mg L−1 lead only, with the last recording the highest lead amount reaching 0.627 mg kg−1 lead (**Table 2**). The findings of the current investigation oppose previous results on different plant species, as they noticed the assemblage of lead in both vegetative and root parts [15, 16, 18, 20].


### **Table 4.**

In vitro *accumulation of cadmium, cobalt, and lead in the root organs of the* Lantana camara *shrub [27].*

### *4.3.3 Bioconcentration factor (BCF)*

Bioconcentration is the concentration of a specific heavy element in the tissues of a plant in comparison with the plant's enclosing concentration of that element [27]. Accordingly, BCF is a necessary indicator of the response of plants to the existence of heavy metals in their environment and a direct indicator of the phytoremediation possibilities. The highest bioconcentration factor values for the cadmium and cobalt examined elements were noticed under 0.8 mg L−1 concentration for both metals, with 0.32 and 0.4 in cadmium and cobalt investigations, respectively (**Table 5**). Cadmium BCF under 0.8 mg L−1 concentration was significantly more increased than that of 0.4 mg L−1 concentration of this metal. Nevertheless, no significant differences were registered between cd BCF values under 0.2, 0.6, and 0.8 mg L−1 concentrations of cadmium. Furthermore, there were no significant differences in BCF factor between 0.4, 0.6, and 0.8 mg L−1 concentrations of cobalt (**Table 5**). The present results are alike to those of findings in Ref. [32] for the BCF factor of cadmium in *B. juncea (L.) Czern*.

As for the lead treatments, 0.6 mg L−1 Pb concentration registered the highest bioconcentration factor data; regardless, there was no significant distinction between bioconcentration data under 0.6 and 0.8 mg L−1 concentrations of lead (**Table 5**).

### *4.3.4 Translocation factor (TF)*

The translocation factor means the level of contaminants assembled in the shoot organs of a plant to those in the root organs [27]. The most increased translocation value in the cadmium investigation was noticed under 0.6 mg L−1 cadmium level (0.67), which was significantly more increased than further levels (**Table 6**). This finding indicates the efficacy of *L. camara* in the translocation of cadmium from the root organs to the shoot organs. Alike findings were acquired by [35] for the transport of cadmium in *Populus alba* and *Morus alba* trees.

About cobalt, the MS medium with a level of 0.2 mg L−1 cobalt was significantly excellent compared with the other treatments with a translocation factor value reaching 4.23.

Furthermore, the TF of lead for all treatments was equal to zero since no lead assemblage was noticed in the shoot organs (**Table 6**).

It was apprised that the perfect plant for phytoremediation should be capable to absorb and assemble heavy metals from contaminated soils and have specific


### **Table 5.**

In vitro *bioconcentration factor (BCF) of Cd, Co, and Pb in* Lantana camara *shrub [27].*

*The Efficiency of Phytoremediation of the Big-Sage Plant in Accumulating Some Heavy Metals… DOI: http://dx.doi.org/10.5772/intechopen.109640*


### **Table 6.**

In vitro *translocation factor (TF) of Cd, Co, and Pb in* Lantana camara *shrub.*

characteristics such as deep and dense roots, large biomass, and rapid growth [36]. This study findings revealed that big sage (*L. camara* L.) could be an active phytoremediator in soils contaminated with cadmium and cobalt because of the suitable translocation factors of these heavy metals.
