Metal tolerance and Cd phytoremoval ability in Pisum sativum grown in spiked nutrient solution.

In the presented study, the effects of cadmium (Cd) stress and silicon (Si) supplementation on the pea plant (Pisum sativum L.) were investigated. The tendency to accumulate cadmium in the relevant morphological parts of the plant (roots and shoots respectively)-bioaccumulation, the transfer of this element in the plant (translocation) and the physiological parameters of the plant through indicators of oxidative stress were determined. Model studies were carried out at pH values 6.0 and 5.0 plant growth conditions in the hydroponic cultivation. It was shown that Cd accumulates mostly in plant roots at both pH levels. However, the Cd content is higher in the plants grown at lower pH. The Cd translocation factor was below 1.0, which indicates that the pea is an excluder plant. The contamination of the plant growth environment with Cd causes the increased antioxidant stress by the growing parameters of the total phenolic content (TPC), polyphenol oxidase activity (PPO), the malondialdehyde (MDA) and lipid peroxidation (LP). The results obtained showed that the supplementation with Si reduces these parameters, thus lowering the oxidative stress of the plant. Moreover, supplementation with Si leads to a lower content of Cd in the roots and reduces bioaccumulation of Cd in shoots and roots of pea plants.

Comprehensive Study of Si-Based Compounds in Selected Plants (Pisum sativum L., Medicago sativa L., Triticum aestivum L.).

This review describes the role of silicon (Si) in plants. Methods of silicon determination and speciation are also reported. The mechanisms of Si uptake by plants, silicon fractions in the soil, and the participation of flora and fauna in the Si cycle in terrestrial ecosystems have been overviewed. Plants of Fabaceae (especially Pisum sativum L. and Medicago sativa L.) and Poaceae (particularly Triticum aestivum L.) families with different Si accumulation capabilities were taken into consideration to describe the role of Si in the alleviation of the negative effects of biotic and abiotic stresses. The article focuses on sample preparation, which includes extraction methods and analytical techniques. The methods of isolation and the characterization of the Si-based biologically active compounds from plants have been overviewed. The antimicrobial properties and cytotoxic effects of known bioactive compounds obtained from pea, alfalfa, and wheat were also described.

Speciation of metals in indigenous plants growing in post-mining areas: Dihydroxynicotianamine identified as the most abundant Cu and Zn ligand in Hypericum laricifolium.

Ag, As, Cu, Pb and Zn were found to be the principal metallic contaminants of a post-mining area of Peru (Hualgayoc, Cajamarca). Study of metal distribution amongst roots, stems, and leaves of four indigenous hypertolerant plant species, Arenaria digyna, Puya sp., Hypericum laricifolium, Nicotiana thyrsiflora indicated significant translocation of Zn (0.6 < TF ≤ 10.0) and Cu (0.4 < TF ≤ 6.5) into aerial plant organs and substantial water-extractable fraction (20-60%) of these metals, except for A. digyna (root and stems). A study of the metal speciation by ultrahigh-performance size-exclusion (fast-SEC) and hydrophilic ion interaction (HILIC) liquid chromatography with dual ICP (inductively coupled plasma) and electrospray (ESI) Orbitrap MS detection revealed the presence of nicotianamine and deoxymugineic acid copper and zinc complexes in roots, stem and leaves of N. thyrsiflora and Puya sp., and nicotianamine alone in A. digyna. A previously unreported compound, dihydroxy-nicotianamine was identified as the most abundant Cu and Zn ligand in H. laricifolium. The presence of arsenobetaine and an arsenosugar was confirmed by ESI MS. Ag and Pb were hardly translocated to leaves and were found as high molecular species; one of the Pb-containing species co-eluted in fast-SEC-ICP MS with rhamnogalacturonan-II-Pb complex commonly found in in the walls of plants.

Accumulation of As, Ag, Cd, Cu, Pb, and Zn by Native Plants Growing in Soils Contaminated by Mining Environmental Liabilities in the Peruvian Andes.

The capability of native plant species grown in polluted post-mining soils to accumulate metals was evaluated in view of their possible suitability for phytoremediation. The study areas included two environmental liabilities in the Cajamarca region in the Peruvian Andes. The content of As, Ag, Cd, Cu, Pb, and Zn was determined in individual plant organs and correlated with soil characteristics. The degree of the pollution depended on the metal with results ranging from uncontaminated (Cd) to moderately (Zn), strongly (As, Cu), and extremely contaminated (Pb, Ag) soils. The metals were mainly present in the fractions with limited metal mobility. The bioaccumulation of the metals in plants as well the translocation into overground organs was determined. Out of the 21 plants evaluated, Pernettya prostrata and Gaultheria glomerate were suitable for Zn, and Gaultheria glomerata and Festuca sp. for Cd, phytostabilization. The native species applicable for Cd phytoremediation were Ageratina glechonophylla, Bejaria sp., whereas Pernettya prostrata Achyrocline alata,Ageratina fastigiate, Baccharis alnifolia, Calceolaria tetragona, Arenaria digyna, Hypericum laricifolium, Brachyotum radula, and Nicotiana thyrsiflora were suitable for both Cd and Zn. None of the studied plants appeared to be suitable for phytoremediation of Pb, Cu, As and Ag.