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The present experiment was designed to evaluate physico-chemical characteristics and phyto-genotoxicity of arsenic (As) contaminated soil collected from different sites of Lakhimpur, Uttar Pradesh (UP), India by employing Vicia faba L. The analyses included various biochemical as well as cyto-genotoxicity assays. The results showed that soil pH was slightly acidic to neutral in nature. The bulk density (1.18–1.23 gcm−3), particle density (2.51–2.59 gcm−3) and porosity (44–53%) varied in different places. The level of available nutrients, nitrogen, phosphorus and potassium was found to vary as 124–165 mgkg-1, 173–186 mgkg-1 and 48–98 mgkg-1, respectively. The maximum As levels were found in soil of Fulvareya (27.13 mgkg−1) and Atareya (24.12 mgkg−1), the level of As in water samples of these sites were 0.19 mgl−1and 0.21 mgl−1, respectively. Phytotoxicity of the As present in soils was evident through significant increases in stress metabolites, hydrogen peroxide (H 2 O 2), malondialdehyde (MDA) and carbonyl groups in root and shoot of V. faba. Cyto-genotoxic effects were also seen through reduced mitotic index (MI) and increased mitotic depression (MD), relative abnormality rate (RAR) as well as other chromosomal abnormalities along with micronuclei in root meristematic cells of V. faba. The phytotoxicity and cyto-genotoxicity assessment suggests the harmful soil properties that might affect biota. • Phyto-Genotoxicity of arsenic contaminated soil was assayed using Vicia faba L. • Phytotoxic markers showed increased oxidative stress like H 2 O 2 , MDA and carbonyl groups. • Genotoxic markers measured via induced frequency of various chromosomal anomalies. • Vicia faba L. can serve as a promising bioindicator for arsenic toxicity. [ABSTRACT FROM AUTHOR]

Abstract The rapid pace of industrial, agricultural and anthropogenic activities in the 20th century has resulted in contamination of heavy metals across the globe. Arsenic (As) is a ubiquitous, naturally occurring toxic metalloid, contaminating the soil and water and affecting human health in several countries. Several physicochemical methods exist for the cleanup of As contamination but these are expensive and disastrous to microbes and soil. Plant based remediation approaches are low cost and environmentally safe. Hence, extensive biochemical, molecular and genetic experiments have been conducted to understand plants’ responses to As stress and have led to the identification of potential genes. The available knowledge needs to be utilized to either reduce As accumulation in crop plants (rice) or to enhance As levels in shoots of hyperaccumulators (Pteris vittata). Gene manipulation using biotechnological tools can be an effective approach to exploit the potential genes (plasmamembrane and vacuolar transporters, glutathione and phytochelatin biosynthetic enzymes, etc.) playing pivotal roles in uptake, translocation, transformation, complexation, and compartmentalization of As in plants. The transgenic plants with increased tolerance to As and altered (increased/decreased) As accumulation have been developed. The need, however, exists to design plants with altered expression of two or more genes for harmonizing various events (like arsenate reduction, arsenite complexation, sequestration and translocation) so as to achieve desirable reduction (crop plants) or increase (phytoremediator plants) in As content. This review sheds light on transgenic approaches adopted to modulate As levels in plants and proposes future directions to achieve desirable results. Highlights • Arsenic is a toxic metalloid and a potential health hazard across the globe. • Arsenic stress responsive mechanisms and responsible crucial genes have been identified. • This review deals with the use of transgenic plants as an effective approach for arsenic removal. • The review also discusses the use of potential genes for lowering arsenic accumulation in crop plants. [ABSTRACT FROM AUTHOR]

The increasing industrialization and urbanization are also triggering environmental pollution, mostly unnoticed, in the case of soil pollution due to uncontrolled contamination by toxic elemental dispersion. The present study focused on this aspect and studied the clean-up of urban soil in a low-cost and eco-friendly way to restrict arsenic (As), lead (Pb) and mercury (Hg) contamination. Four potential ornamental plants, C atharanthus roseus (vinca) , Cosmos bipinnatus (cosmos) , Gomphrena globose (globosa) and Impatiens balsamina (balsamina) were used along with zero valent iron (ZVI) nanoparticles (Fe NPs) for remediation of the soil spiked with As (70 mg kg−1), Pb (600 mg kg−1) and Hg (15 mg kg−1) in a 60 d pot experiment. All plants were divided into four groups viz. control, spiked, spiked+20 mg kg−1 ZVI NP and spiked+50 mg kg−1 ZVI NP. FTIR and SEM were used for ZVI NP characterization. Soil and plant analyses and elemental assessments were done using ICP-MS, XRF and SEM. Among the four plants, cosmos showed the maximum accumulation of toxic elements (41.24 ± 0.022 mg kg−1 As, 139.15 ± 11.2 mg kg−1 Pb and 15.57 ± 0.27 mg kg−1 Hg) at 60 d. The application of ZVI NP at 20 mg kg−1 dosage was found to further augment plants' potential for metal(loid)s accumulation without negatively hampering their growth. Cosmos were observed to reduce soil As from 81.35 ± 1.34 mg kg−1 to 28.16 ± 1.38 mg kg−1 (65.38%), Pb from 1132.47 ± 4.66 to 516.09 ± 3.15 mg kg−1 (54.42%) and Hg from 17.35 ± 0.88 to 6.65 ± 0.4 mg kg−1 (61.67%) at 60 d in spiked + 20 mg kg−1 ZVI NP treatment. Balsamina was the most sensitive plant and showed the least metal(loid)s accumulation. In conclusion, three of these plants are potent enough to use together for a better and enhanced removal of toxic elements from the contaminated soil with cosmos to be the best amongst these in urban areas. [Display omitted] • Soil arsenic, lead and mercury contamination in urban areas is addressed. • Potential flowering plants were tested for phytoremoval of soil metal(loid)s. • The best, Cosmos bipinnatus, removed soil As (65.38%), Pb (54.42%) and Hg (61.67%). • Applied 20 ppm Fe nanoparticles assist plants in more efficient element removal. • Post-experimental soil was found having low bioavailability of selected elements. [ABSTRACT FROM AUTHOR]