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Abstract: Sesuvium portulacastrum (L.) L., a facultative halophyte, is considered a suitable candidate for the phytoremediation of metals. An investigation of As accumulation and tolerance was conducted in Sesuvium plants upon exposure to As(V) (100–1000μM) for 30d. Plants demonstrated a good growth even after prolonged exposure (30d) to high As(V) concentrations (1000μM) and a significant As accumulation (155μgg−1 dry weight) with a bioaccumulation factor of more than ten at each concentration. The results of shoot and root dry weight, malondialdehyde accumulation, photosynthetic pigments, and total soluble proteins demonstrated that plants did not experience significant toxicity even at 1000μM As(V) after 30d. However, metabolites (total non-protein thiols and cysteine) and enzymes (serine acetyltransferase, cysteine synthase and γ-glutamylcysteine synthetase) of thiol metabolism, in general, remained either unaffected or showed slight decline. Hence, plants tolerated high As(V) concentrations without an involvement of thiol metabolism as a major component. Taken together, the results indicate that plants are potential As accumulator and may find application in the re-vegetation of As contaminated sites. [ABSTRACT FROM AUTHOR]

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 present study analysed the levels of potentially toxic elements along with physico-chemical properties of agricultural soil samples (n = 59) collected from fields situated along the path of river Ganga in the middle Gangetic floodplain in two districts, Ballia and Ghazipur. Arsenic (As), chromium (Cr), copper (Cu), nickel (Ni), zinc (Zn), lead (Pb), iron (Fe) and manganese (Mn) levels were analysed by Wavelength Dispersive-X-Ray Fluorescence Spectroscopy (WD-XRF) and the associated health risks along with diverse indices were calculated. The mean concentrations of As, Cu, Cr, Pb, Zn and Ni were found to be 15, 42, 85, 18, 87 and 47 mg kg−1, respectively in Ballia and 13, 31, 73, 22, 77 and 34 mg kg−1, respectively in Ghazipur. Physico-chemical properties like pH, ORP and organic matter were found to be 7.91, 209 and 1.20, respectively in Ballia and 8.51, 155 and 1.25, respectively in Ghazipur. The calculated health quotient (HQ) for all the elements was observed to be within the threshold value of one, however with few exemptions. Therefore, the present study showcases the contamination of potentially toxic elements in agricultural fields and possible health hazards for people. [Display omitted] • Agricultural soil were collected from middle Gangetic Basin in Uttar pradesh, India. • PTE's (As, Cr, Pb, Zn, Ni, and Cu) concentration were analysed by WD-XRF method. • Hazard quotient and Incremental lifetime cancer risk (ILCR) were analysed. [ABSTRACT FROM AUTHOR]