Elemental Composition of Dasiphora fruticosa (L.) Rybd. Varieties
Olga V. Goryacha1, Аlla М. Kovaleva1, Ain Raal2, *, Тetiana V. Ilina2, Оleh M. Коshovyi2, Zoia V. Shovkova3
Identifiers and Pagination:Year: 2022
E-location ID: e187433152201240
Publisher ID: e187433152201240
Article History:Received Date: 22/7/2021
Revision Received Date: 30/11/2021
Acceptance Date: 29/12/2021
Electronic publication date: 10/03/2022
Collection year: 2022
open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: https://creativecommons.org/licenses/by/4.0/legalcode. This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
The aim of the study is to study the elemental composition of the leafy shoots, rhizomes, and roots of D. fruticosa varieties cultivated in Ukraine.
Dasiphora fruticosa (L.) Rybd. (Rosaceae) is a species native to Middle Asia and the Far East. More than 130 D. fruticosa varieties are known; plants have a significant raw material base and are promising objects for phytochemical research. Data only on the elemental composition of the aboveground parts of the wild-grown D. fruticosa is present. No information on the elemental composition of the raw materials of cultivated D. fruticosa varieties is available.
A comprehensive analysis of the elemental composition of Dasiphora fruticosa varieties and identification of the features of macro- and microelements translocation.
For all D. fruticosa varieties, raw materials were taken from two plants with five replicates per plant. The elemental composition was studied by atomic absorption spectroscopy. Using corresponding formulas, translocation factors of elements were determined, and a hygienic full-value of the raw materials was established.
In the studied raw materials, fourteen elements were identified and quantified. The translocation factors of potentially toxic elements Mo, Cu, Ni, and Sr indicate a capture of these elements in the root system and a presence of the barrier mechanisms preventing their accumulation in D. fruticosa varieties shoots.
The results obtained show the presence of the barrier mechanisms preventing the accumulation of potentially toxic elements in aboveground parts of D. fruticosa varieties and justify a need for the study of those mechanisms.
Dasiphora Rafin. is a small genus of the subfamily Rosoideae of the family Rosaceae; as follows from different scientific sources, this genus comprises 5 or 6 species. Dasiphora plants are erect, less commonly prostrate shrubs growing mainly on rocks, rocky slopes, and along the banks of rivers. Dasiphora species are typical representatives of the flora of the Northern Hemisphere and the largest areas are characteristic of Siberia and Central Asia [1, 2].
Taxonomic independence of Dasiphora Rafin. genus species, as well as a generic name, are disputable. Dasiphora spp. are classified to Potentilla L. genus as shrubby cinquefoils ; S. K. Cherepanov classifies these plants to Pentaphylloides Hill genus ; some researchers support Dasiphora Rafin. genus as a separate taxonomic unit [5, 6]. By The Plant List, the name Dasiphora Rafin. is an accepted name, but Dasiphora fruticosa (L.) Rybd. is disputable, which is a synonym of Potentilla fruticosa L. .
Dasiphora fruticosa (L.) Rybd. (Potentilla fruticosa L., Pentaphylloides fruticosa (L.) O. Schwarz) is an erect, less commonly prostrate branchy silky-pubescent ornamental shrub of 20-150 сm height. Branches covered with brown or gray bark; leaves more or less large, pinnate, 5 less frequently 7 leaflets each, leaflets oblong in shape, entire with pointed ends. Flowers yellow, up to 3 cm in diameter, solitary or in small apical inflorescence. The plant grows along the banks of rivers, in bushes, floodplains, on the rocky slopes, and outcrops. The species is common to Central and Atlantic Europe, Scandinavia, the Caucasus, Siberia, Central Asia, and the Far East . In Tibetan medicine, D. fruticosa is used in the treatment of gastrointestinal tract diseases, pulmonary tuberculosis, and lobar pneumonia; the species is the nectariferous plant and is used as a tea substitute . D. fruticosa is a valuable shrub with more than 130 varieties distinguished by flowers colour and size .
The whole plants of D. fruticosa have several pharmacological activities, such as antimicrobial and anti-viral activities. They contain immune-boosting properties as well as the ability to lower cholesterol and blood sugar levels. Due the high amounts of hyperoside, ellagic acid, and (+)-catechin, the leaf extract from D. fruticosa may display significant antioxidant activity in vitro and protective effects on Escherichia coli under peroxide stress .
Due to the undemanding cultivation requirements, resistance against environmental factors and a significant raw material base, we consider D. fruticosa as a promising object for phytochemical research.
A number of articles have shown the elemental composition of the aboveground parts of the wild-grown D. fruticosa [11, 12] and a generalized model of the distribution of some elements in the taxon has been proposed . However, in the available scientific primary sources, there are no data on the elemental composition of the aboveground parts of D. fruticosa varieties, as well as underground organs of both wild-grown plants and cultivated varieties.
We believe that the analysis of plant elemental composition should be comprehensive and include the study of the elemental composition of both aboveground parts and underground organs since such information helps understand the features of macro- and microelements translocation, and hence, show the presence of the barrier mechanisms preventing the accumulation of certain elements in plant aboveground parts, as well as justify the need for the study of those mechanisms.
The present article aims to study the elemental composition of shoots and rhizomes and roots of Dasiphora fruticosa (L.) Rybd. varieties cultivated in Ukraine, and identify the features of the translocation of macro- and microelements. It was also reasonable to determine the total ash of the raw materials.
2. MATERIALS AND METHODS
2.1. Plant Samples
The objects of the study were the raw materials (RMs), namely leafy shoots, rhizomes, and roots of three D. fruticosa varieties, namely ‘Primrose Beauty’, the compact shrub, crown diameter up to 1.2 m; flowers light yellow, small, numerous, blooming time: mid-June – mid-September; ‘Goldfinger’, the shrub 1 – 1.5 m high, up to 1.5 m wide; leaves dark green; flowers numerous, intensely yellow, up to 5 cm in diameter, blooming time: June – October; ‘Princess/Pink Queen’, the shrub up to 80 cm high; crown pulvinate, up to 1.2 m in diameter; leaves dark green; flowers pink, 3-3.5 cm in diameter; blooming time: May – October.
All D. fruticosa varieties were purchased in spring 2019 from plant nurseries at the age of approx. 3 years. Plants were transplanted and grew for approx. 1.5 year before sampling. For each D. fruticosa variety, all RMs were taken from two plants with five replicates per plant and mixed to obtain corresponding combined samples.
The leafy shoots (app. 25 g per each plant) were harvested in the flowering and early fruiting phase in August-September 2020 (Kyiv region, Petropavlivska Borshchahivka village, (Table 1); immediately after harvesting, shoots were rinsed and then dried in an oven at 40-45° C. Rhizomes and roots were harvested in November 2020, and immediately after harvesting, were washed thoroughly with running water and dried in the oven at 45-50° C. The oven-dried RMs were stored in paper bags in a dry place protected from light.
2.2. Determination of Elemental Composition
The elemental composition of RMs was determined using a DFC-8 atomic emission spectrophotometer at the premises of the State Scientific Institution “Institute for Single Crystals” of the NAS of Ukraine. Accurately weighted grounded raw material samples (passed through a 2 mm sieve) were treated with sulfuric acid and carefully ashed in a muffle furnace (temperature was not more than 500 °С) for 1 hour. The samples were evaporated from the craters of graphite electrodes. There were the following conditions of spectra photographing: the amperage of the arc AC – 16 А, the ignition phase – 60°, the frequency of the pulses ignited – 100 discharges per second; the analytical interval – 2 mm; the width of the spectrograph slit – 0.015 mm; exposure – 60 s; as a source of spectra excitation IBC-28 was used. The spectra were recorded on photographic plates using a DFC-8 spectrophotometer with a three-lens system of the slit illumination and diffraction screen of 600 lines/mm. Measurement of the line intensities in the spectra of the samples analyzed was performed using an MF-4 microphotometer at a wavelength from 240 to 347 nm compared to the standard samples of elements – calibration samples [14, 15].
The translocation factor (TF) was calculated as the ratio of the element’s concentration in the shoots to that in the rhizomes and roots (Formula 1) [16, 17]:
TF = СShoots / СRhizomes and roots (Formula 1)
Hygienic full-value (HFV) was calculated as the ratio of Ca concentration to Sr concentration in RM (Formula 2) :
HFV = ССа / СSr (Formula 2)
The total ash of RMs was determined according to the procedure given in the State Pharmacopoeia of Ukraine .
2.3. Statistical Analysis
All measurements were performed five times for each combined sample. The mean and standard deviation (SD) for each combined sample were calculated according to the State Pharmacopoeia of Ukraine .
3.1. The Elemental Profile of Dasiphora Fruticosa Varieties
In the studied RMs of D. fruticosa varieties, 19 elements were identified and quantified, namely 9 microelements (Si, Fe, Al, Mn, Mo, Cu, Zn, Sr, Ni) and 5 macroelements (K, Na, Ca, Mg, P); the translocation factors of elements from the root system to the shoots were determined (Table 2). The elements were ranked in the descending order of their concentration: ‘Goldfinger’, shoots: К˃Са˃Mg˃Si=Р˃Аl˃Fe˃Na˃Мn˃Zn˃ Sr˃Сu˃Mo˃Ni; rhizomes and roots: К˃Са˃Р˃Mg˃Na˃ Si=Fe˃Мn˃Аl˃Sr˃Zn˃Сu˃Mo˃Ni; ‘Primrose Beauty’, shoots: К˃Са˃Mg˃Si˃Р˃Аl˃ Na=Fe˃Мn˃Zn˃Sr˃Сu˃ Mo˃Ni; rhizomes and roots: Са˃К˃Mg˃Р˃Na˃Si˃Fe=Аl˃Sr˃ Мn=Zn˃Сu˃Mo˃Ni; ‘Princess/Pink Queen’, shoots: К˃Са˃Mg˃Р˃Si˃Na˃Аl˃ Мn˃Fe˃Zn˃Sr˃Сu˃Mo˃Ni; rhizo mes and roots: К˃Са˃Р˃Mg˃Si˃Na˃Fe=Мn˃ Zn˃Аl˃ Sr˃Сu˃Mo˃Ni.
The highest content of macroelements was determined in D. fruticosa var. ‘Princess/Pink Queen’ shoots (185.98±5.88 mg/kg). Of all the RMs, the content of microelements was the highest in D. fruticosa var. ‘Primrose Beauty’ shoots (27.27±1.11mg/kg).
In RMs, the composition of the prevailing elements was similar, but their content differed. In D. fruticosa var. ‘Goldfinger’ shoots macroelements K, Ca, and Mg prevailed; K and Ca prevailed in rhizomes and roots. K, Ca, Mg, and Si were the prevailing macroelements in D. fruticosa var. ‘Primrose Beauty’ shoots, in rhizomes and roots Ca, K, and Mg prevailed. The prevailing macroelements of D. fruticosa var. ‘Princess/Pink Queen’ shoots were K, Ca, and Mg, in rhizomes and roots K and Ca prevailed. The obtained profiles of the prevailing macroelements are comparable with the corresponding profiles of the representatives of the family Rosaceae Juss. [21-23].
|Dasiphora Fruticosa (L.) Rybd. Variety||Geographical Coordinates|
|‘Primrose Beauty’||50°26'04.0”N 30°19'22.3”E|
|‘Princess/Pink Queen’||50°26'05.8”N 30°19'22.7”E|
|Element||D. fruticosa Variety, Content*, mg/kg, mean ± SD (n=5).|
|‘Goldfinger’||‘Primrose Beauty’||‘Princess/Pink Queen’|
|Shoots||Rhizomes and Roots||TF||Shoots||Rhizomes and Roots||TF||Shoots||Rhizomes and Roots||TF|
|Sum of macroelements||152.98±2.29||78.94±2.29||-||148.4±2.59||81.67±0.42||-||185.98±5.88||86.82±2.21||-|
|Sum of microelements||21.53±0.49||10.5±0.23||27.27±1.11||14.07±0.30||15.69±0.43||8.66±0.17|
«-» – the value was not determined; * – mg/kg in the oven-dried RMs
|D. fruticosa Variety||[Ca], mg/kg||[Sr], mg/kg||[Ca]/[Sr] Ratio|
|Rhizomes and Roots|
|D. fruticosa Variety||Total Ash, %, Mean ± SD (n=5)|
|‘Goldfinger’||3.52 ± 0.14|
|‘Primrose Beauty’||4.83 ± 0.24|
|‘Princess/Pink Queen’||4.75 ± 0.22|
|Rhizomes and Roots|
|‘Goldfinger’||2.66 ± 0.14|
|‘Primrose Beauty’||2.89 ± 0.12|
|‘Princess/Pink Queen’||2.09 ± 0.10|
Since an excessive accumulation of Sr in bone tissue occurs only with a lack of body Ca, we believe it is important to use in pharmaceutical production only herbal medicinal materials meeting requirements to the ratio between the concentrations of Ca and Sr (hygienic full-value requirement). Considering relatively high concentrations of Sr in the D. fruticosa RMs, we studied the conformity of all RMs with hygienic full-value requirements and established that shoots of the studied D. fruticosa varieties conform with those requirements (Table 3).
The highest content of total ash was in D. fruticosa var. ‘Primrose Beauty’ shoots (4.83 ± 0.24%); the lowest – in D. fruticosa var. ‘Princess /Pink Queen’ rhizomes and roots (2.09 ± 0.10%), (Table 4).
The results obtained (Table 2) are generally consistent with the data on the composition and content of macro- and microelements in D. fruticosa from natural areas. E. V. Andysheva et al.  and E.P. Khramova et al.  studied the elemental composition of leaves and shoots of wild-growing D. fruticosa by the method of X-ray fluorescence analysis using synchrotron radiation. According to their findings, only K and Ca represented macroelements. However, in our study, Na, Mg and Р were additionally identified and quantified in leafy shoots, giving a more detailed macroelement pattern of D. fruticosa aboveground organs. We also first characterized the composition of macroelements in D. fruticosa roots and rhizomes. The content of K in aboveground organs of wild-grown D. fruticosa and cultivated varieties was comparable, but Ca concentration was 2-fold higher in RMs of wild-grown D. fruticosa.
As relating to microelements, previous studies [11, 12] revealed the presence of 19 microelements in leaves and shoots of wild-growing D. fruticosa. Here we report only 9 microelements in leafy shoots of D. fruticosa varieties. Both in the above ground organs of wild-grown and cultivated D. fruticosa plants, the following microelements were identified and quantified: Fe, Mn, Mo, Cu, Ni, Sr, and Zn.
Concentrations of Ni, Cu, Zn, Sr, and Mo in all the studied RM samples were less than 0.01%. However, the content of Fe in leafy shoots of cultivated varieties exceeded that in leaves and shoots of wild-growing D. fruticosa by 2.2-2.7 times; as well as Mn concentration was 2-fold higher in leafy shoots of cultivated varieties.
The following heavy metals were absent in the studied RMs or were beyond the device’s determination capabilities: Pb (<0.003), Co (<0.003), Cd (<0.001), As (<0.001), and Hg (<0.001). Previously we studied the content of toxic elements in the branches of Salix spp. and found that fortunately, Cd and Pb (both <0.003 mg/kg), Cd, As, and Hg (all <0.001 mg/kg) were absent or not within the range of determination by the method of emission spectrometry. According to The Commission of the European Communities (2006), the maximum allowed concentrations for Cd and Pb are 0.05 and 0.2 mg/kg/bw for vegetables, berries, and fruits, which are much more than detected in Salix species and D. fruticosa varieties by us .
In D. fruticosa aboveground organs, we first reported Si and Al, the presence of which may result from environmental and cultivation conditions.
Microelements in D. fruticosa roots and rhizomes were first studied.
The translocation factors of potentially toxic elements Mo, Cu, Ni, and Sr (Table 2) indicate a capture of these elements in the root system (TF˂1), as well as the presence of the barrier mechanisms that prevent the accumulation of these elements in shoots of the studied D. fruticosa varieties [24, 25]. All the studied varieties were capable of capturing Mo and Cu; roots and rhizomes of D. fruticosa var. ‘Goldfinger’ and D. fruticosa var. ‘Primrose Beauty’ captured Sr; only D. fruticosa var. ‘Primrose Beauty’ roots and rhizomes were capable of capturing Ni.
Whereas Al, Si, and K were actively transported to the shoots. The maximum TF values of Al were established for D. fruticosa var. ‘Goldfinger’ and D. fruticosa var. ‘Princess/Pink Queen’ (5.16 and 3.07, respectively); D. fruticosa var. ‘Primrose Beauty’ is characterized by the highest TF of Si (3.49) and Mn (2.76).
Potentially toxic elements Fe, Al, Mn, Mo, Cu, Sr, Ni, and Zn were present in the RMs of the studied D. fruticosa varieties. Only in D. fruticosa var. ‘Goldfinger’ rhizomes and roots Cu content slightly exceeded the MPC (1.62 MPC); however, in all RMs, Zn content significantly exceeded the MPC . For instance, in the shoots of three varieties, Zn content was 8.6-12.2-folds higher than the MPC; in rhizomes and roots, the MPC for Zn was exceeded by 4.8-11.5 times.
Due to the absence of the regulatory requirements for the content of Sr in RM, we considered it would be reasonable to determine the hygienic full-value of the studied plant objects (Table 3). Hygienic full-value is the ratio between the concentrations of Ca and Sr; the minimum permissible value is “80” . Hygienic full-value is an important parameter of feed and food crop quality, but we considered it would be reasonable to determine this parameter for studied RMs. We found that only shoots of the studied D. fruticosa varieties meet the requirements for hygienic full-value ([Ca]/[Sr]˃80).
Considering the absence of the relevant information on the permissible levels of Fe, Al, Ni, Mn, and Mo in plants and substances of herbal origin, as well as taking into account the significant excess of Zn MPC in RMs, in the future, we propose to control the safety of the developed herbal drug preparations taking into account the maximum permissible daily doses of microelements [27, 28], as well as to determine the compliance of the herbal drug preparations with the requirements of ICH Q3D (R1)  and to monitor their hygienic full-value.
D. fruticosa varieties are not pretentious to cultivation conditions, are resistant against environmental factors, and potentially have barrier mechanisms preventing translocation of potentially toxic elements to aboveground parts of D. fruticosa varieties. The results obtained emphasize the need for the increase in the number of the subject D. fruticosa varieties, as well as the need for the comprehensive study of the features of macro- and microelements accumulation in order to justify the prospects for the use of D. fruticosa varieties as phytoremediants [30-33].
The elemental composition of the shoots and rhizomes and roots of Dasiphora fruticosa (L.) Rybd. varieties cultivated in Ukraine, namely ‘Goldfinger’, ‘Primrose Beauty’ and ‘Princess/Pink Queen’ was first studied. For three D. fruticosa varieties, translocation factors of macro- and microelements were calculated. The barrier functions of the root system of D. fruticosa varieties in relation to potentially toxic elements Mo and Cu (all varieties), Ni (D. fruticosa var. ‘Goldfinger’ and D. fruticosa var. ‘Primrose Beauty’) and Sr (D. fruticosa var. ‘Primrose Beauty’) were shown, justifying a need for the study of possible barrier mechanisms. The obtained data on the elemental composition and hygienic full-value of raw materials will be used in the development, as well as during the control of the safety of medicinal products from the studied raw materials.
ETHICS APPROVAL AND CONSENT TO PARTICIPATE
HUMAN AND ANIMAL RIGHTS
No animals/humans were used for studies that are the basis of this research.
CONSENT FOR PUBLICATION
AVAILABILITY OF DATA AND MATERIALS
The authors confirm that the data supporting the findings of this study are available within the article.
The research was funded by the Ministry of Health Care of Ukraine at the expense of the State Budget in the framework # 2301020 “Scientific and scientific-technical activity in the field of health protection” on the topic “Modern approaches to the creation of new medicines for a correction of metabolic syndrome”.
CONFLICT OF INTEREST
Dr. Ain Raal is the Editorial Board Member of The Open Agriculture Journal..
|||Yuzepchuk SV, Ed. Flora of the USSR 1941; 10|
|||Baikov KS, Ed. Check-list of flora of Asian Russia: Vascular plants 2012. [in Russian]|
|||Flora of China. Available from: efloras.org/florataxon.aspx?flora_id=2&taxon_id=304106 [Accessed April 05, 2021].|
|||Vascular plants of Russia and the adjacent states (within the former USSR) Cherepanov SK, Mir i Sem'ya , Eds. 1995. [in Russian]|
|||Chen X, Li J, Cheng T, et al. Molecular systematics of Rosoideae (Rosaceae). Plant Syst Evol 2020; 306(9): 9.
|||Eriksson T, Hibbs MS, Yoder AD, Delwiche CF, Donoghue MJ. The phylogeny of Rosoideae (Rosaceae) based on sequences of the internal transcribed spacers (ITS) of nuclear ribosomal DNA and the Trnl/F region of chloroplast DNA. Int J Plant Sci 2003; 164(2): 197-211.
|||The Plant List. A working list of all plant species. Available from: theplantlist.org/tpl1.1/record/rjp-8070 [Accessed June 06, 2021].|
|||Sokolov PD, Ed. The plant resources of the USSR: Flowering plants, their chemical composition, use; Hydrangeaceae-Haloragaceae families 1987.|
|||Miller DM. RHS pant trials and awards: Shrubby Potentilla. Available from: rhs.org.uk/plants/pdfs/plant-trials-and-awards/plant-bulletins /potentilla.pdf [Accessed April 09, 2021].|
|||Zeng Y, Sun Y-X, Meng X-H, Yu T, Zhu H-T, Zhang Y-J. A new methylene bisflavan-3-ol from the branches and leaves of Potentilla fruticosa. Nat Prod Res 2020; 34(9): 1238-45.
|||Andysheva EV, Chankina OV, Khramova EP, Krestov PV, Rakshun YaV, Sorokoletov DS. Comparative study of element composition of species of the genus Dasiphora (Rosaceae) in the Primorsky region and Republic of Buryatia. Siberian J Physics 2019; 14(4): 105-17.
|||Khramova EP, Chankina OV, Syeva SYa, Kostikova VA. Features of the accumulation of mineral elements of the mountain Altai shrubs. Plant Life of Asian Russia 2019; 3(35): 62-9.
|||Pavlov VE, Khramova EP, Khvostov IV, et al. A generalized model of the distribution of some elements in Pentaphylloides fruticosa. Chem Plant Raw Mat 2008; 3: 163-8.|
|||Osmachko AP, Kovaleva AM, Ili’ina TV, Koshovyi ON, Komisarenko AM, Akhmedov EYu. Study of macro- and microelements composition of Veronica longifolia L. herb and Veronica teucrium L. herb and rhizomes, and extracts obtained from these species. AZƏRBAYCAN ƏCZAÇILIQ və FARMAKOTERAPİYA JURNALI 2017; 1: 24-8.|
|||Borodina N, Ain R, Kovalyov V, Koshovyi O, Ilina T. Macro- and microelements in the branches of some Salix genus species in the flora of Ukraine. Int J Med Res Prof 2020; 9(3): 71-80.|
|||Nworie OE, Qin J, Lin C. Trace element uptake by Herbaceous plants from the soils at a multiple trace element-contaminated site. Toxics 2019; 7(1): 3.
|||Galal TM, Shehata HS. Bioaccumulation and translocation of heavy metals by Plantago major L. grown in contaminated soils under the effect of traffic pollution. Ecol Indic 2015; 48: 244-51.
|||Lavrishchev AV. Studying the behaviour of stable strontium in agroecosystems of the north-west of Russia. Doctoral Thesis 2016.|
|||State Pharmacopoeia of Ukraine; RIREG 2001.|
|||State Pharmacopoeia of Ukraine 2nd. 2 supp.2018.|
|||Imbrea I, Radulov I, Nicolin A, Imbrea F. Analysis of macroelements content of some medicinal and aromatic plants using flame atomic absorption spectrometry (FAAS). Rom Biotechnol Lett 2016; 21(4): 11642-51.|
|||Shohayeb M, Arida H, Abdel-Hameed E-SS, Bazaid S. Abdel-Hameed, El-S. S., Bazaid, S. Effects of macro- and microelements in soil of rose farms in taif on essential oil production by Rosa damascena Mill. J Chem 2015; 2015: 1-7.
|||Van der Ent A, Mulligan DR, Repin R, Erskine PD. Foliar elemental profiles in the ultramafic flora of Kinabalu Park (Sabah, Malaysia). Ecol Res 2018; 33(3): 659-74.
|||Yan A, Wang Y, Tan SN, Mohd Yusof ML, Ghosh S, Chen Z. Phytoremediation: A promising approach for revegetation of heavy metal-polluted land. Front Plant Sci 2020; 11: 359.
|||De-Jesús-García R, Rosas U, Dubrovsky JG. The barrier function of plant roots: Biological bases for selective uptake and avoidance of soil compounds. Funct Plant Biol 2020; 47(5): 383-97.
|||Kukhniuk OV. Research of heavy metal accumulation by agricultural products of Cherkasy region. Available from: tnv-agro.ksauniv.ks.ua/archives/115_2020/15.pdf (Accessed April 20, 2021) [in Ukrainian]|
|||Institute of Medicine. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc.2001.
|||Joint FAO/WHO expert committee on food additives. Available from: fao.org/3/ca5270en/ca5270en.pdf (Accessed April 20, 2021).|
|||International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use. Guideline for Elemental Impurities Q3D(R1) Available from: ema.europa.eu/en/documents/scientific-guideline/international-conference-harmonisation-technical-requirements-registration-pharmaceuticals-human-use_en-21.pdf (Accessed April 20, 2021)|
|||Asgari Lajayer B, Khadem Moghadam N, Maghsoodi MR, Ghorbanpour M, Kariman K. Phytoextraction of heavy metals from contaminated soil, water and atmosphere using ornamental plants: Mechanisms and efficiency improvement strategies. Environ Sci Pollut Res Int 2019; 26(9): 8468-84.
|||Gajić G, Djurdjević L, Kostić O, Jarić S, Mitrović M, Pavlović P. Ecological potential of plants for phytoremediation and ecorestoration of fly ash deposits and mine wastes. Front Environ Sci 2018; 6: 124.
|||Wu B, Peng H, Sheng M, et al. Evaluation of phytoremediation potential of native dominant plants and spatial distribution of heavy metals in abandoned mining area in Southwest China. Ecotoxicol Environ Saf 2021; 220112368
|||Pasricha S, Mathur V, Garg A, Lenka S, Verma K, Agarwal S. Molecular mechanisms underlying heavy metal uptake, translocation and tolerance in hyperaccumulators-an analysis: Heavy metal tolerance in hyperaccumulators. Environment Challeng 2021; 4100197