## 3 Results and Discussion
### Accumulation and Translocation of PTEs  
Data shown in Table 2 represent bioconcentration factors (BCF) in various PTEs. BCF determines the plants ability to concentrate xenobiotics present in the soil into the plant body. This shows which plants are suitable for the process of phytoremediation (BCF > 1) [12]. The presented results show that the BCF value for none of the observed PTEs was higher than 1. This indicates (Table 3) that _M. albus_ does not effectively accumulate any of the observed PTEs in its roots. Similar results are shown in [PERSON] et al. [4], where BCF of _M. officinalis_ for Cu was 0.75 in the polluted soil. However, with the addition of fertilizer combined with EDTA, the BCF factors increased to 1.43. In the case of plants grown on a highly polluted dumping site in India, a generally higher BCF was determined for Cd [10; 46]. Similarly, the BCF of Cd for _Plantago major_ sampled close to a heavy traffic road was 23.33 and Cd was the most accumulated heavy metal [48]. Values of bioaccumulation factor (BAC) for _M. albus_ can be found in Table 2. This parameter shows the efficiency of plants to accumulate xenobiotics in the above-ground biomass. Similarly, to BCF, a BAC > 1 indicates a plant species suitable for phytoextraction processes [43; 44]. The BAC parameter was lower than 1 in all observed PTEs, which indicates a low ability of the species to accumulate these xenobidhcs in their shoot tissue. [PERSON] et al. [36] investigated the BAC of the legume _Cyamopsis tetragonolba_ and the non-fixing plant _Sesammum indicum_ exposed to soils loaded with Pb. They observed that under the lowest loadings BAC and BCF exhibited the highest values (100 mg/kg). However, with the rising concentration of Pb in the soil, the observed parameters decreased. In case of the highest Pb concentration (1000 mg/kg), BCF and BAC decreased by 57.3 and 42.1%, respectively, when compared to 100 mg/kg. In the present study, the plants were grown in the soil without artificially added PTEs. \begin{table}
\begin{tabular}{c c c c} \hline  & **BCF** & **BAC** & **TF** \\ \hline Sb & n.d. & n.d. & 0.57 \(\pm\) 0.19 a \\ As & 0.15 \(\pm\) 0.09 b & 0.11 \(\pm\) 0.003 b & 0.39 \(\pm\) 0.08 a \\ Cd & n.d. & n.d. & 0.80 \(\pm\) 0.31 a \\ Cu & 0.26 \(\pm\) 0.03 a & 0.20 \(\pm\) 0.04 a & 0.79 \(\pm\) 0.12 a \\ Ni & 0.04 \(\pm\) 0.01 c & 0.023 \(\pm\) 0.003 c & 0.76 \(\pm\) 0.25 a \\ Pb & 0.03 \(\pm\) 0.028 c & 0.06 \(\pm\) 0.02 d & 1.51 \(\pm\) 1.40 a \\ Hg & 0.04 \(\pm\) 0.02 c & 0.08 \(\pm\) 0.03 d & 1.76 \(\pm\) 0.90 a \\ Se & n.d. & n.d. & 0.63 \(\pm\) 0.28 \\ Zn & 0.16 \(\pm\) 0.1 b & 0.18 \(\pm\) 0.06 a & 1.39 \(\pm\) 0.58 a \\ \hline \end{tabular} Data represent mean \(\pm\) standard deviations over at least 5 replications. Different letters indicate significant differences in concentration of individual HM in soil (ANOVA, \(p\) < 0.05, post hoc Tukey’s HSD test). n.d. = not detected.  
\end{table} 
Table 2: Translocation factor (TF), bioconcentration factor (BCF), and bioaccumulation factor (BAC) in _M.__Mellotus albus_ for the respective detected PTEs. \begin{table}
\begin{tabular}{c c c} \hline  & **Low Accumulation** & **Accumulator** \\ \hline BAC & \textless{}1.0 & \textgreater{}1.0 \\ BCF & \textless{}1.0 & \textgreater{}1.0 \\ TF & \textless{}1.0 & \textgreater{}1.0 \\ \hline BAC = bioaccumulation factor, BCF = bioconcentration factor, TF = translocation factor. & \\ \hline \end{tabular}
\end{table} 
Table 3: Phytoremediation potential of plants based on BAC, BCF, and TF according to [PERSON] et al. [4]. Table 2 shows the values of translocation factor (TF) which is used to evaluate the suitability of plants for phytoextraction processes. TF\(>\)1 indicates that plants are suitable for the phytoextraction of specific PTE [4]. Differences in TF among the individual PTEs were not statistically significant. PTEs are mostly represented by heavy metals that are absorbed by roots and subsequently transported via symplast (energy-dependent process) into the plant body [49,50].