Distribution Of Micro (Fe, Zn, Cu, and Mn) and Risk (Al, As, Cr, Ni, Pb, and Cd) Elements in the Organs of R. Alpinus L.

Background and aims Rumex alpinus is a native plant in the mountains of Europe, whose distribution is affected by its utilization as a vegetable and medicinal herb. The distribution of micro and risk elements in its organs and the possibility for phytoremediation are not well-known. We aimed to examine the safety of consuming R. alpinus from the Krkonoše Mountains, Czech Republic, and Alps (Austria and Italy). Methods We determined the total and plant-available concentration of Fe, Zn, Cu, Mn, Al, As, Cr, Ni, Pb, and Cd in the soil and total concentration in the organs of R. alpinus using inductively coupled plasma-optical emission spectrometry. Results The uptake and distribution of elements by plants were characterized by bioaccumulation and translocation (TF) factors. The intensity of elements accumulation by R. alpinus is considerably different, depending on locality. R. alpinus has considerable tolerance to Zn, Cu, As, Cr, Ni, with easy accumulation strategy. High Al and Cd concentration in belowground biomass (rhizome) indicates a defensive mechanism for them. Although the aboveground biomass (emerging, senescent, mature leaves, petiole) has some degree of accumulation of risk elements, R. alpinus is potentially suitable for phytoremediation of moderately contaminated soils. The results revealed that R. alpinus excludes Al, with high TF for Mn, Zn, Cu, As, Ni, and Pb. Given the accumulation of As and Cr, we recommend caution in its usage. Detailed elemental analysis of R. alpinus organs is recommended before its application as medicinal herb or food, especially in contaminated soils.


Introduction
The Monk's Rhubarb (Alpine dock), Rumex alpinus L. (R. alpinus), is a perennial plant inhabiting nutrient-rich areas, stream banks, spring areas, pastures, and meadows. It is native to the mountains of Central and Southern Europe. The distribution of R. alpinus currently results from its utilization as a vegetable and medicinal herb in the past. It is one of the historic food plants in preparing the dish, "farchon"-made of steamed Chenopodium bonus-henricus, Urtica dioica, and R. alpinus in the Alps region (Maude et al. 2005). In Albania, this species is the most quoted and used wild food plants, used as vegetables mainly cooked with dairy products and rice or as lling for homemade savory pies (Pieroni and Quave 2014).
In alpine localities, some organs of this species serve various purposes, e.g., leaves to a surrogate of sauerkraut or spinach, stems peeled and applied instead of rhubarb, or eaten fresh or put into cakes, biscuits, and puddings (Dickson and Dickson 2000; Šťastná et al. 2010). The leaves, seeds, rhizomes, and roots of R alpinus most often are used for the treatment of several health disorders, e.g., diarrhea, dysentery, constipation, stomach disorders, kidney disorders, eczema, jaundice, fever, and cancer (Hartwell 1970;Rácz et al. 1992;Jang et al. 2012).
In traditional Austrian medicine, the leaves and roots of R. alpinus have been used internally for the treatment of viral infections (Bogl et al. 2013). R. alpinus additionally, has emerged suitable for the treatment of in ammation and different bacterial infections (Vasas et al. 2015). Given the bene ts of R. alpinus to health-related issues, it is pertinent to perform a detailed analysis of the bioaccumulation of elements in the organs of this species. The nutritional status of most plants better re ects in the mineral element concentrations of the leaves (Marschner et al. 1996). However, studies on the distribution of elements (e.g., trace and risk) below-and other above-ground biomass of R. alpinus are not well-known.
Atmospheric depositions from anthropogenic activities, e.g., metallurgy, remain one of the crucial sources of trace/risk elements (such as Cu, Zn, Cd, and Pb) in soils. Soil contamination with trace metals represents a risk for crop production, food quality, and human health because of their high toxicity and the ability of plants to bioaccumulate. Notably, trace metals have high persistency in the environment and relatively high mobility (Mench 1998;Sucharová and Suchara 2004;Wuana and Okieimen 2011). However, R. alpinus grows mainly in mountainous areas, especially in protected areas with minimal or no impacts of anthropogenic activities. Hence, trace element concentrations can only result from lithogenic and probably be within permissible limits for soils. Moreover, R. alpinus usually grow in nutrient-rich areas, with the tendency of the soils contaminated by risk elements and still use as food and medicine. For example, in the Krkonoše Mountains, Czech Republic, R. alpinus have widely distributed in locations with historic mining of Fe ore and arsenic (As) in the 15th -17th Century AD, with reported high possibility of soil contamination by trace metals (Lokvenc 2007;Tásler 2012).
The possibility of R. alpinus use in phytoremediation has been considered as a plant with high biomass encountered in many ecosystems (Klimeš 1992;Šťastná et al. 2010), rendering it suitable for phytoextraction of metal from moderately contaminated soil (Szabó and Fodor 2006;Cui et al. 2004;Turgut et al. 2004). Notwithstanding, studies concerning the bioaccumulation of trace and risk elements by this species are de cient.
A signi cantly high amount of plant biomass can compensate for a relatively low capacity for metal accumulation, resulting in a large amount of heavy metal removed from the soil (Zhuang et al. 2007). The uptake and transport of microelements by plants can be well-estimated by the bioaccumulation factor (BF); the plant-to-soil concentration ratio of elements (Baker 1981; Klink et al. 2014;Vondráčková et al. 2014). According to Baker (1981), plants that accumulate micro and risk elements are characterized by a BF and translocation factor (TF) > 1, indicator plants by a BF and TF = 1, and plants that exclude these elements by a BF and TF < 1. Thus, this study adopted these indices in estimating bioaccumulation factors of trace metals of R. alpinus from different localities in the temperate zone.
In this present study, we aimed to examine the safety of consuming Alpine dock obtained from Krkonoše Mountains. and Alpines localities by asking the following research questions; (1) to what extent can R. alpinus accumulate trace metals and whether it is suitable for phytoremediation? and (2) which organs of R. alpinus are accumulators of micro and risk elements? This exploratory study seeks to analyze the concentration of elements in the different organs of the studied species to determine their suitability for human consumption and other medicinal purposes. Thus, it is crucial to consider trace metal concentrations of such a plant, especially for environmental quality assessment.

Study area
The current study was conducted in typical stands of R. alpinus in the Krkonoše Mountains of the Czech Republic and the alps of Austria and Italy, all in the temperate zone (Fig. 1). The selected sites were studied according to their wide distribution of the studied species (see Table 1 for a detailed description of each studied locality).

Soil sampling and preparation
To cover the variability of soil samples in the sampled locations of R. alpinus stands, we adopted a speci c sampling design. We sampled the upper 10 cm soil layer with a soil probe (Purchhauer type, core-diameter: 30 mm). In each sampled locality (LB, VT, PC, HM, DCH, and MD), we randomly collected ten soil samples around the R. alpinus stands. In total, 60 soil samples were collected for further analysis.
All the soil samples were air-dried and subsequently, oven-dried at 70 °C for 48 hours. The samples were grounded in a porcelain mortar and homogenized by sieving through a 2 -mm sieve after removal of roots and other debris.

Plant organs sampling and preparation
Organs of R. alpinus were collected in a mono-dominant stand that covered 100 m 2 in all the localities (Fig. S2). Samples from above (stem, emerging, mature, and senescent leaves, and petiole) and below-ground (rhizomes) biomass were collected in all the sampled localities (Fig. 2).
In each locality, we collected ten emerging semi-developed leave blades (E), ten fully developed mature leave blades (M), ten senescent (yellow, red, or brown semi-dry) leave blades (S), ten petioles from mature leaves (Pe), ten stems without seeds (St), and three rhizomes (R) developed in the last two years: with enough energy storage (Araki et al. 2020, Fig 2). The samples from Krkonoše Mountains were collected in July during the summer (S) and in October 2018 in the autumn (A). Samples from the Alps localities were collected only once in July 2018, approximately the same time as Krkonoše mountains samples. The collected samples were kept in paper bags and transported to the laboratory. All the plant organs initially were cleaned from soil and other residues in a distilled H 2 O and dried for 48 hours at 70 °C. The organs were ground and homogenized in an IKA A11 basic analytical mill (IKA ® -Werke GmbH & Co. KG, Germany).

Chemical analyses of soils and plant organ samples
The total concentrations of Fe, Zn, Cu, Mn, Al, As, Cr, Ni, Pb, and Cd in the soils and plant organs were extracted using the USEPA 3052 extraction procedure (USEPA, 1996) -extraction mixture of HNO 3, HCl, and HF.
Usage-a mass of 0.25 g of homogenized R. alpinus individual organs was mineralized in a mixture of 9mL HNO 3 and 3mL HCl and 1 mL HF and heated in a sealed 60 mL VWR ® PTFE Jar on a hot plate at 150 °C for 24 h. After 24 hours 1 ml of peroxide was added to each sample and evaporated on a hot plate at 50 °C for 24 h. The evaporated samples were then diluted to 20 mL by 2% HNO 3 for two hours and ltrated. Total concentration was determined by Inductively coupled plasmaoptical emission spectrometry (ICP-OES, 720 Series, Agilent Technologies, USA). The plant organs and soil samples were measured in three replicates. In the case of the determination of the total concentration of elements in the soil samples, we used the same approach as in the case of the plant organs.
The plant-available fraction of Fe, Zn, Cu, Mn, Al, As, Cr, Ni, Pb, and Cd in the soil was analyzed by Mehlich-III reagent (Mehlich, 1984)

Statistical analyses
Data on pH, the elemental concentrations in the organs of R. alpinus, and soil samples were tested by the Kolmogorov-Smirnov test of normality and met assumptions for the use of parametric tests. There was relative homogeneity of variance among obtained data. Factorial ANOVA was used to determine the signi cant difference among the concentration of elements in different organs of R. alpinus from all the localities. One-way ANOVA was used to determine the signi cant difference among the concentration of elements in the organs and soil overall localities.
In all cases, post-hoc comparison using the Tukey HSD test was applied to identify signi cant differences between the concentration of elements in different organs and soils. All statistical analyses were performed using the STATISTICA 13.3 program (www.statsoft.com).

Estimation of bioaccumulation (BF) and translocation factors (TF)
The BF was calculated by the following equation, The BF of the leaf was estimated for total element concentration in emerging and mature leaves by the available in the soil, without senescent (degenerative part).
The TF was calculated by the following equation, We used the mean total concentration of elements in the mature leaf and the rhizome. One-way ANOVA was used to determine the signi cant difference between BF and TF of the studied elements in all the localities.

pH and concentration of elements in soils
We recorded a signi cant effect of locality on pH [H 2 O] ( Table 2). The pH of the soil samples in all the analyzed localities ranged from 5.2 -6.1. Except for a slightly acidic reaction in DCH, soils in all other localities were moderately acidic, which can result in increased availability of elements to plants.
The statistical description of total and plant-available concentrations of the studied elements is in Tables 2 and 3, respectively.
There was a signi cant effect of locality on the total concentrations of the micro (Fe, Zn, Cu, and Mn) and risk (Al, As, Cr, Ni, Pb, and Cd) elements ( Table 2). The total concentration of Fe ranged from 13.6 -27.5 g kg -1 in DCH and HM, respectively. The total concentration of Zn ranged from 48 in DCH to 182 mg kg -1 in PC. The concentration of total Cu ranged from 4.7 in DCH to 39.8 mg kg -1 in LB. The total Mn ranged from 178 in MD to 693 mg kg -1 in VT. Moreover, the total Al concentration ranged from 11.1 in LB to 27.1 g kg -1 in VT. The concentration of total As was from 3.9 in DCH to 70.9 in HM. The total Cr concentration ranged from 20.6 in MD to 53.2 mg kg -1 in HM. The concentration of Ni ranged from 11.65 in DCH to 28 mg kg -1 in HM. The total concentration of Pb ranged from 13.2 in DCH to 70.8 mg kg -1 in HM. The concentration of total Cd ranged from 0.43 in DCH to 1.35 mg kg -1 in HM.
Except for Cr, there was a signi cant effect of locality in the concentration of plant-available elements ( Table 3). The available fraction of Fe ranged from 204 -657 mg kg -1 in DCH and HM, respectively. The plant-available concentration of Zn ranged from 5.1 in DCH to 62 mg kg -1 in PC. The plant-available Cu ranged from 0.7 in HM to 7.9 mg kg -1 in MD. The available Mn concentration ranged from 43 in MD to 189 mg kg -1 in PC. The plant-available concentration of Al ranged from 648 -1720 mg kg -1 in PC and HM, respectively. The available As concentration was from 0.35 in DCH to 3.64 mg kg -1 in LB. The plant available Cr ranged from 0.12 in LB and HM to 0.31 mg kg -1 in MD. The concentration of available Ni was from 0.34 in DCH to 1.85 mg kg -1 in LB. The plant-available concentration of Pb ranged from 2.15 in HM to 21 mg kg -1 in PC. Finally, the available concentration of Cd ranged from 0.06 in MD to 0.51 mg kg -1 in LB.

Concentration of total elements in plant organs
The concentration of the elements in all analyzed organs' overall localities is given in Figs. 3 -6 and Table S1. There was a signi cant effect of organ, locality, and organ/locality interaction on the concentration of all the analyzed elements. The mean total concentrations of the elements in different organs are in Table S1. In the Krkonoše Mountains, there was a signi cant effect of organ and terms (summer and autumn) in the concentration of Fe, Cu, Mn, Al, As, Cr, and vice versa in the case of Zn, Ni, Pb, and Cd (Figs. 7 and 8). The concentration of Fe ranged from 15 in the stem from LB during summer (LB_S) to 818 mg kg -1 in senescent leaves at HM in autumn (HM_A). The mean Fe concentration in organs' overall localities was Pe<St<E<M<R<S (Fig.  3a). Except for mature and senescent leaves, the concentration of Fe was higher in summer than autumn (Fig. 7a). The concentration of Zn ranged from 6 in stem from PC_S to 212 mg kg -1 in rhizome from VT_A. The mean Zn concentration in organs' overall localities and collection terms was Pe<St<S<M<E<R (Fig. 3b). The concentration of Zn was higher in autumn than in summer (Fig. 7b). The Cu concentration was from 0.7 in stem from PC_ A to 13.1 mg kg -1 in emerging leaves from VT_S. The mean Cu concentration in organs' overall localities and collection terms was St<Pe<S<R<M<E (Fig. 4a). The concentration of Cu was higher in summer than in autumn (Fig. 7c). The Mn concentration ranged from 4.5 in the stem from ZL to 322 mg kg -1 in senescent leaves in MD. The mean Mn concentration in organs' overall localities and collection terms was St<R<Pe<E<M<S (Fig.  4b). Except for rhizome, Mn concentration was higher in autumn than in summer (Fig. 7d).
The concentration of Al ranged from 15 in emerging leaves to 1590 mg kg -1 in the petiole from LB_A and VT_S, respectively. The mean of Al concentration in organs in all localities and collection terms was E<St<M<R<S<Pe (Fig. 5a). Except for stem and rhizome, Al concentration was higher in summer than in autumn (Fig. 8a). The concentration of As ranged from 0.009 in emerging leaves in ZL to 5 mg kg -1 in senescent leaves in PC_A. The mean of As concentration in organs' overall localities and collection terms was St<M<E<R<S<Pe (Figure 5b). Except for emerging leaves, the concentration of As was higher in autumn than in summer (Fig. 8b). The level of Cr ranged from 0.06 in mature leaves in DCH to 6.6 mg kg -1 in rhizome in ZL, and the mean concentration in organs' overall localities and collection terms was Pe<E<M<S<St<R (Fig. 5c). The Cr concentration was higher in autumn than in summer (Fig. 8c). The concentration of Ni was from 0.01 in stem from PC_S to 6.6 mg kg -1 in rhizome in VT_A.
The mean of Ni concentration in organs' overall localities and collection terms was Pe<St<M<S<E<R (Fig. 6a). The level of Ni in all organs was higher in autumn than in summer (Fig. 8d). Pb concentration ranged from 0.001 in petiole and rhizome in LB_S to 8.2 mg kg -1 in senescent leaves in HM_A. The mean Pb concentration in organs' overall localities and collection terms was R<M<Pe<St<S<E (Fig. 6b). The level of Pb was higher in autumn than in summer (Fig. 8e). The concentration of Cd in organs across the Alps localities was mostly below detection except for rhizome, which recorded 0.8 -1 mg kg -1 in Zl and MD, respectively. In Krkonoše Mountains, Cd concentration was from 0.1 in emerging leaves in VT_S to 3.9 mg kg -1 in rhizome from VT_A. The mean of Cd concentration in organs' overall localities and collection terms was R<M<Pe<St<S<E (Fig. 6c). The concentration of Cd was higher in autumn than in summer (Fig. 8f).

BF (leaf ÷ soil)
The results of BF of micro and risk elements are in Table 4. There was a signi cant effect on locality for all the elements. BF for Fe in all localities was < 1, with a mean value of 0.28. The BF for Zn was < 1 only in two localities (LB_A, PC_S, and PC_A) and a mean value of 2.8. Similar results (BF<1) were obtained for Cu in LB_A, LB_S, and PC_A, with a mean value of 4.5. BF for Mn in all localities, except for HM_A and MD_S, was below 1, and the mean value of 0.74. BF of Al in all localities again was < 1, the mean value was 0.08. BF of As was < 1 in two localities (LB_S, LB_A, PC_S, and MD_S), the mean value was 1.96. BF for Cr was in all the localities > 1 and the mean value was 4.07. In LB_S, PC_S, and HM_S, BF for Ni was < 1, with a mean value of 1.8. However, BF for Pb was > 1 only in one locality (HM_A), and the mean value was 0.64. Similar results were obtained for Cd, where BF was mostly < 1, except for VT_A, PC_A, and HM_A, with a mean value of 0.76.

BF (petiole ÷ soil)
In all the localities, BF for Fe was < 1, and the mean value of 0.11. Again, the BF of Zn was below 1 only in two localities (LB_S and LB_A, PC_S and PC_A), with a mean value of 1.98. The BF in petiole for Cu was > 1 only in VT_S, HM_S, HM_A, and DCH_S, with a mean value of 1.96. The BF of Mn was > 1 only in two localities (HM_A and MD_S), with a mean value of 0.74. Similar results were recorded for BF of Al, with only two localities (VT_S and DCH_S) > 1 and a mean value of 0.36.
Additionally, in all the localities, except for MD_S, BF of As was > 1, with a mean value of 2.6. A similar pattern was recorded for BF of Cr in all the localities, except MD_S was > 1 and the mean value was 3.7. The BF for Ni was in four localities (VT_S, VT_A, HM_A, DCH_S, and MD_S) > 1, with the mean value of 1.3. We recorded BF of Pb only in VT_A, HM_A, and DCH_S > 1. R. alpinus was an indicator of Pb in one locality (HM_S), and the mean value was 0.55. In only LB_A, R. alpinus was Cd indicator and in two localities (VT_A and HM_A) BF was > 1, with a mean value of 1.3.

BF (rhizome ÷ soil)
In all localities except for DCH_S, BF for Fe was < 1, with a mean value of 0.44. In only one locality (PC_S and PC_A), BF for Zn was < 1, with a mean value of 5.7. Two localities (LB_S and LB_A, PC_S and PC_A) recorded BF for Cu < 1, the mean value was 2.5. The BF for Mn in all localities, except (MD_S) was < 1, and a mean value of 0.45. In all localities, the BF of Al was below 1, with a mean value of 0.17. For As, we recorded BF in three localities (LB_S and LB_A, PC_S and PC_A, DCH_S) below 1, and the mean value was 1.25. Moreover, in all localities except for MD_S, recorded BF > 1 for Cr and the mean value was 9.3. Opposite results were recorded for BF of Mn, in all localities, except (MD_S), were < 1, with a mean value of 0.45. BF for Ni in only two localities (LB_S and PC_S) was below 1, the mean value was 2.2. Only one locality (HM_A) had BF of Pb above 1, the mean value was 0.47. The BF of Cd in only PC_S and DCH_S were < 1, and a mean value of 5.6.

TF (leaf ÷ rhizome)
The mean TF of Al, Cr, and Fe was < 1 ( Table 5). Only in PC_A was TF of Al above 1 and in MD Cr was above 1. TF of Cd was < 1 in all the localities. The TF for Fe was above 1 in autumn in localities LB, PC, and HM. The TF of Cu, Mn, Ni, and Pb were mostly above 1.

Discussion
The main message of this study is that the edibility of R. alpinus can be questionable, considering the accumulation and distribution of risk elements in different organs of this species. The intensity of elements accumulation by R. alpinus is considerably site-speci c. The release of the trace and risk elements relates to the lithogenic and anthropogenic (e.g., metallurgy) sources resulting in the subsequent accumulation in different departments of R. alpinus. Moreover, the accumulation of risk elements such as As, Cr, Ni, Pb, and Cd was affected by season. In addition to acidic soil, the dissolution by precipitation H 2 O during the autumn contributed to the release of elements (Truog 1947), re ected in higher concentrations in the organs during autumn compared to summer in localities of the Krkonoše Mountains. (2002), Cd concentration in uncontaminated soils ranges from 0.05 -2 mg.kg -1 , thus, in VT and LB, Cd exceeded this range in rhizome during autumn. The concentrations of As, was above Czech legislative limits (20 mg kg -1 ) at LB, VT, HM, and MD, indicating a risk to the safety of food or feed, direct danger to human or animal health in contact with soil, and a negative impact on the production function of agricultural land (Kabata-Pendias and Pendias 2001). In the Krkonoše localities, the soils remain contaminated by As probably due to arsenopyrite mining in the past (Tásler 2012).

Distribution of Fe, Zn, Cu, Mn, Al, As, Cr, Ni, Pb, and Cd in the organs
The selection of adequate plant species with accumulative characteristics is crucial for successful phytoextraction processes.
Hyperaccumulating plants frequently reach low biomass, pest management, or harvesting practices as main drawbacks for their utilization for metal phytoextraction (Wenzel et al. 1999 Table S1). A different distribution of Cu was in emerging and mature leaves, which is not consistent with the distribution of Cu in below-ground organs of Rumex acetosa (Gaweda 2009  . In this study, the mean total concentration of Al was lowest in emerging leave and highest in the petiole, followed by the rhizome, due to low transport from below-ground organs to leaf: a defensive mechanism against high concentration of Al in plants (Poschenrieder et al. 2008). In comparison with the experiment by Vondráčková et al. (2015), concerning R. obtusifolius, the recorded values in the organs of this study were low, which indicates that R. alpinus prevents the intake of Al. The mean total concentration of As in individual organs ranged from 1-1.8 mg kg -1 , which slightly exceeds the limit according to Kabata-Pendias and Pendias (2001). Arsenic concentration in the leaves was lower and higher in petiole and senescent leaves, which indicates that the plant tried to get rid of it. The mean total concentration of Cr in R. alpinus organs of this study was lower compared to the results of Rumex obtusifolius, according to Vondráčková et al. (2014). While their results showed the highest Cr concentration in the leaves, we obtained the lowest in emerging, mature leaves and the highest in stem and rhizome. However, these results are comparable to Gaweda (2009), who studied Rumex acetosa. Notably, the different results in varying degrees relate to the species, anthropogenic activities, and the soil chemical properties.

Transport and accumulation of elements by R. aphinus
From the results of this study, R. alpinus has a strategy to exclude Fe, Mn, and Pb, although the concentration of some of the elements was high (e.g., Fe) in the soil. R. alpinus accumulated Mn only in MD and HM, even with the lowest plant-available concentration in the soil, perhaps because the plants used this element as essential. The situation was similar for Zn. In this case, the studied species exclude Zn in localities with high availability in the soil (e.g., in PC) and vice versa in localities with the lowest available Zn, rending them accumulators (Zhao et al. 2003). In localities with a low concentration of Zn in the soil, Zn levels in the plant organs were lower than localities with higher concentration: a similar result reported by Barrutia  , where R. obtusifolius is a hyperaccumulator of Al, we expected a similar strategy with R. alpinus. However, the results showed that R. alpinus is an excluder of Al and can exudate chelating ligands, form a pH barrier at the rhizosphere, cell wall immobilization, and selective permeability of the plasma membrane.
The TF represents a phytoextraction parameter used to evaluate the capacity of each accession to translocate metals from rhizome to leaves. In our study, the mean TF found from all localities was higher than 1 for Zn, Cu, Mn, As, Ni and Pb. The BF results suggest an accumulation strategy for Cr, which accumulated in both terms at all localities except the petiole and rhizome at MD. However, TF for Cr was below 1, following the high concentration of these risk elements in the rhizome. Probably, high tolerance by R. alpinus to Cr has not con rmed accumulation strategy in all localities except MD.

Conclusions
According to this study, the level of micro and risk elements bioaccumulation is considerably site-speci c. Our analysis strongly revealed that R. alpinus has considerable tolerance to As, Cr, Zn, Cu, and Ni, but easy bioaccumulation of these elements. Thus, considered a plant for phytoremediation. The high concentration of elements such as Al and Cd in the below-ground biomass (rhizome) indicates a defensive mechanism (excluder) for high concentrations of risk elements.
Additionally, the accumulation of As, Cr, Ni, Pb, and Cd by R. alpinus was affected by seasonal changes. For example, precipitation H 2 O during the autumn can contribute to the release of elements in the soil, evident in higher concentrations in the organs compared to summer in localities of the Krkonoše Mountains.R. alpinus has also revealed the accumulation ability (accumulator) for As and Cr. Although the above-ground biomass (emerging, mature leaves, and petiole) has some degree of accumulation of other elements (e.g., Cu), R. alpinus is potentially suitable for the phytoremediation of moderately contaminated soils. The study also showed a signi cant translocation for Zn, Cu, Mn, As, Ni, and Pb by R. alpinus. Hence, we recommend great caution while consuming this vegetable on contaminated soils.
Therefore, we recommend, detailed elemental analysis of the organs of the studied species before its application as medicinal herb and food, especially in contaminated soils.

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