| 1. |
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| 2. |
- Hossain, Monayem, et al.
(författare)
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Silicon alleviates arsenic-induced toxicity in wheat through vacuolar sequestration and ROS scavenging
- 2018
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Ingår i: International journal of phytoremediation. - : Taylor & Francis. - 1522-6514 .- 1549-7879. ; 20:8, s. 796-804
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Tidskriftsartikel (refereegranskat)abstract
- Arsenic (As) is a phytotoxic element causing health hazards. This work investigates whether and how silicon (Si) alleviates As toxicity in wheat. The addition of Si under As-stress significantly improved morphophysiological characteristics, total protein, and membrane stability compared to As-stressed plants, suggesting that Si does have critical roles in As detoxification in wheat. Analysis of arsenate reductase activity and phytosiderophore (PS) release reveals their no involvement in the Si-mediated alleviation of As in wheat. Furthermore, Si supplementation in As-stressed plants showed a significant increase of As in roots but not in shoots compared with the plants grown under As stress. Further, gene expression analysis of two chelating molecules, TaPCS1 (phytochelatin synthase) and TaMT1 (metallothionein synthase) showed significant induction due to Si application under As stress compared with As-stressed plants. It is consistent with the physiological observations and suggests that alleviation of As toxicity in rice might be associated with As sequestration in roots leading to reduced As translocation in shoots. Furthermore, increased catalase, peroxidase, and glutathione reductase activities in roots imply the active involvement of reactive oxygen species scavenging for protecting wheat plants from As-induced oxidative injury. The study provides mechanistic evidence on the beneficial effect of Si on As toxicity in wheat plants.
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| 3. |
- Islam, Md Shofikul, et al.
(författare)
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Elevated concentrations of serum matrix metalloproteinase-2 and -9 and their associations with circulating markers of cardiovascular diseases in chronic arsenic-exposed individuals
- 2015
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Ingår i: Environmental Health. - : BioMed Central (BMC). - 1476-069X. ; 14:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Cardiovascular diseases (CVDs) and cancers are the major causes of chronic arsenic exposure-related morbidity and mortality. Matrix metalloproteinase-2 (MMP-2) and −9 (MMP-9) are deeply involved in the pathogenesis of CVDs and cancers. This study has been designed to evaluate the interactions of arsenic exposure with serum MMP-2 and MMP-9 concentrations especially in relation to the circulating biomarkers of CVDs.Methods: A total of 373 human subjects, 265 from arsenic-endemic and 108 from non-endemic areas in Bangladesh were recruited for this study. Arsenic concentrations in the specimens were measured by inductively coupled plasma mass spectroscopy (ICP-MS) and serum MMPs were quantified by immunoassay kits.Results: Serum MMP-2 and MMP-9 concentrations in arsenic-endemic population were significantly (p < 0.001) higher than those in non-endemic population. Both MMPs showed significant positive interactions with drinking water (rs = 0.208, p < 0.001 for MMP-2; rs = 0.163, p <0.01 for MMP-9), hair (rs= 0.163, p < 0.01 for MMP-2; rs = 0.173, p < 0.01 for MMP-9) and nail (rs= 0.160, p < 0.01 for MMP-2; rs = 0.182, p < 0.001 for MMP-9) arsenic of the study subjects. MMP-2 concentrations were 1.02, 1.03 and 1.05 times, and MMP-9 concentrations were 1.03, 1.06 and 1.07 times greater for 1 unit increase in log-transformed water, hair and nail arsenic concentrations, respectively, after adjusting for covariates (age, sex, BMI, smoking habit and hypertension). Furthermore, both MMPs were increased dose-dependently when the study subjects were split into three (≤10, 10.1-50 and > 50 μg/L) groups based on the regulatory upper limit of water arsenic concentration set by WHO and Bangladesh Government. MMPs were also found to be significantly (p < 0.05) associated with each other. Finally, the concentrations of both MMPs were correlated with several circulating markers related to CVDs.Conclusions: This study showed the significant positive associations and dose–response relationships of arsenic exposure with serum MMP-2 and MMP-9 concentrations. This study also showed the interactions of MMP-2 and MMP-9 concentrations with the circulating markers of CVDs suggesting the MMP-2 and MMP-9 -mediated mechanism of arsenic-induced CVDs.
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| 4. |
- Junnarkar, Manisha, et al.
(författare)
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Probiotic potential of lactic acid bacteria from fresh vegetables : Application in food preservation
- 2019
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Ingår i: Indian Journal of Experimental Biology. - New Delhi, India : National Institute of Science Communication and Information Resources. - 0019-5189 .- 0975-1009. ; 57, s. 825-838
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Tidskriftsartikel (refereegranskat)abstract
- Fresh vegetables are potential source of lactic acid bacteria (LAB). In the present study, LAB were isolated from the fresh vegetables from Pune region. Total 266 LAB were isolated from the edible parts of fresh vegetables viz. cauliflower, gherkins, cluster beans, fenugreek, cow pea, bitter gourd, french beans, tomato, ridged gourd, cucumber and bottle gourd. On phenotypic and molecular characterization predominant genera obtained were Lactobacillus, Enterococcus and Weissella. Twenty one isolates exhibited tolerance to bile salt, acidic pH and pancreatin. Cellular extracts of several isolates with ability to survive in artificial intestinal condition additionally showed antioxidant potential and cell free supernatants xhibited antibacterial potential against selected plant and human pathogens. Bacteriocin and bacteriocin like substances (BLS) substances secreted by these isolates can be used for food preservation.
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| 5. |
- Junnarkara, Manisha V., et al.
(författare)
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Evaluation of Probiotic Potential of Lactic Acid Bacteria Isolated from Different Sources in Western India
- 2018
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Ingår i: Food biotechnology. - United Kingdom : Taylor & Francis. - 0890-5436 .- 1532-4249. ; 32:2, s. 112-129
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Tidskriftsartikel (refereegranskat)abstract
- Lactic acid bacteria isolated from unconventional sources are often attractive targets in the quest for obtaining better probiotics. In the present study, 16 members of the genus Lactobacillus, isolated from 3 different sources in western India, viz., plants, fermented foods and beverages, and human feces, were evaluated for their probiotic and bioactive properties. The isolates were closely related to Lactobacillus fermentum, Lactobacillus pentosus, and mainly Lactobacillus plantarum. The isolates were tolerant to bile salt, acidic pH and pancreatin, although pancreatin tolerance was generally low. Cellular extracts of several isolates displayed antioxidant activity, while cell-free supernatants displayed antibacterial activity against human pathogens. Antioxidant activity of Lactobacilli of human origin was higher than those from vegetables or fermented foods and beverages. L. plantarum AG40V prevented spoilage of fresh-cut fruits, vegetables and sprouted mung-beans. Lactobacilli from all sources displayed equal probiotic potential and those of human origin displayed superior antioxidant activity over others.
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| 6. |
- Kabir, Ahmad H., et al.
(författare)
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Role of Silicon Counteracting Cadmium Toxicity in Alfalfa (Medicago sativa L.)
- 2016
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Ingår i: Frontiers in Plant Science. - : Frontiers Media S.A.. - 1664-462X. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- Cadmium (Cd) is one of the most phytotoxic elements causing an agricultural problem and human health hazards. This work investigates whether and how silicon (Si) ameliorates Cd toxicity in Alfalfa. The addition of Si in Cd-stressed plants caused significant improvement in morpho-physiological features as well as total protein and membrane stability, indicating that Si does have critical roles in Cd detoxification in Alfalfa. Furthermore, Si supplementation in Cd stressed plants showed a significant decrease in Cd and Fe concentrations in both roots and shoots compared with Cd-stressed plants, revealing that Si-mediated tolerance to Cd stress is associated with Cd inhibition in Alfalfa. Results also showed no significant changes in the expression of two metal chelators [MsPCS1 (phytochelatin synthase) and MsMT2 (metallothionein)] and PC (phytochelatin) accumulation, indicating that there may be no metal sequestration or change in metal sequestration following Si application under Cd stress in Alfalfa. We further performed a targeted study on the effect of Si on Fe uptake mechanisms. We observed the consistent reduction in Fe reductase activity, expression of Fe-related genes [MsIRT1 (Fe transporter), MsNramp1 (metal transporter) and OsFRO1 (ferric chelate reductase] and Fe chelators (citrate and malate) by Si application to Cd stress in roots of Alfalfa. These results support that limiting Fe uptake through the down-regulation of Fe acquisition mechanisms confers Si-mediated alleviation of Cd toxicity in Alfalfa. Finally, an increase of catalase (CAT), ascorbate peroxidase (APX) and superoxide dismutase (SOD) activities along with elevated methionine and proline subjected to Si application might play roles, at least in part, to reduce H2O2 and to provide antioxidant defense against Cd stress in Alfalfa. The study shows evidence of the effect of Si on alleviating Cd toxicity in Alfalfa and can be further extended for phytoremediation of Cd toxicity in plants.
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| 7. |
- Mandal, Abul, 1952-
(författare)
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Transgenic tobacco plants expressing ACR2 gene of Arabidopsis thaliana exhibit reduced accumulation of arsenics and increased tolerance to arsenate
- 2015
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Ingår i: Transgenic tobacco plants expressing <em>ACR2</em> gene of <em>Arabidopsis thaliana</em> exhibit reduced accumulation of arsenics and increased tolerance to arsenate. - : Omics International Conference. ; , s. 32-
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Konferensbidrag (refereegranskat)abstract
- Transgenic tobacco plants expressing ACR2 gene of Arabidopsis thaliana exhibit reduced accumulation of arsenics and increased tolerance to arsenate.Toxic metals such as arsenics, lead, cadmium or chromium are the major environmental pollutants that severely contribute to contamination of the global food chain directly through their accumulation in the edible parts of the cultivated crops or indirectly via meat-milk pathway. Fortunately, plant genetic engineering has the potential for developing new crop cultivars for removal of the toxic substances from the polluted sources or for avoiding accumulation of these contaminants in the edible parts. Previously, we have identified and studied four key genes that are involved in accumulation of arsenics in plants (J Biol. Systems 2010, 18/1:1-19; J Mol. Modeling 2012, DOI 10.1007/s00894-012-1419 and J Mol. Modeling 2014, DOI 10.1007/s00894-014-2104). In this study, we have cloned and transformed the ACR2 gene (arsenic reductase 2) of Arabidopsis thaliana into tobacco plants (Nicotiana tabacum). Our results revealed that the transgenic tobacco plants are more tolerant to arsenic than the wild-type control plants. These plants can grow on medium containing 200 µM arsenate, whereas the non-transgenic plants can hardly survive under this condition. Furthermore, when exposed to 100 µM arsenate for 35 days accumulation of arsenics in shoots of the transgenic plants decreases significantly (28 µg/g d wt.) compared to that observed in the non-transgenic control plants (40 µg/g d wt.). This study shows that A. thaliana ACR2 gene is a potential candidate for genetic engineering of plants to develop new cultivars that can be grown on arsenic contaminated fields and can supply harmless foods containing no or significantly reduced amount of arsenics.
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| 8. |
- Nahar, Noor, et al.
(författare)
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Functional studies of AtACR2 gene putatively involved in accumulation, reduction and/or sequestration of arsenic species in plants
- 2017
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Ingår i: Biologia. - : Walter de Gruyter. - 0006-3088 .- 1336-9563. ; 72:5, s. 520-526
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Tidskriftsartikel (refereegranskat)abstract
- Food-based exposure to arsenic is a human carcinogen and can severely impact human health resulting in many cancerous diseases and various neurological and vascular disorders. This project is a part of our attempts to develop new varieties of crops for avoiding arsenic contaminated foods. For this purpose, we have previously identified four key genes, and molecular functions of two of these, AtACR2 and AtPCSl, have been studied based on both in silico and in vivo experiments. In the present study, a T-DNA tagged mutant, (SALK-143282C with mutation in AtACR2 gene) of Arabidopsis thaliana was studied for further verification of the function of AtACR2 gene. Semi-quantitative RT-PCR analyses revealed that this mutant exhibits a significantly reduced expression of the AtACR2 gene. When exposed to 100 μM of arsenate (AsV) for three weeks, the mutant plants accumulated arsenic approximately three times higher (778 μg/g d. wt.) than that observed in the control plants (235 μg/g d. wt.). In contrast, when the plants were exposed to 100 μM of arsenite (AsIII), no significant difference in arsenic accumulation was observed between the control and the mutant plants (535 μg/g d. wt. and 498 μg/g d. wt., respectively). Also, when arsenate and arsenite was measured separately either in shoots or roots, significant differences in accumulation of these substances were observed between the mutant and the control plants. These results suggest that AtACR2 gene is involved not only in accumulation of arsenic in plants, but also in conversion of arsenate to arsenite inside the plant cells. © 2017 Institute of Molecular Biology, Slovak Academy of Sciences.
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| 9. |
- Nahar, Noor, et al.
(författare)
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Phytoremediation of arsenic from the contaminated soil using transgenic tobacco plants expressing ACR2 gene of Arabidopsis thaliana
- 2017
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Ingår i: Journal of plant physiology (Print). - : Elsevier. - 0176-1617 .- 1618-1328. ; 218, s. 121-126
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Tidskriftsartikel (refereegranskat)abstract
- We have cloned, characterized and transformed the AtACR2 gene (arsenic reductase 2) of Arabidopsis thaliana into the genome of tobacco (Nicotiana tabacum, var Sumsun). Our results revealed that the transgenic tobacco plants are more tolerant to arsenic than the wild type ones. These plants can grow on culture medium containing 200μM arsenate, whereas the wild type can barely survive under this condition. Furthermore, when exposed to 100μM arsenate for 35days the amount of arsenic accumulated in the shoots of transgenic plants was significantly lower (28μg/g d wt.) than that found in the shoots of non-transgenic controls (40μg/g d wt.). However, the arsenic content in the roots of transgenic plants was significantly higher (2400μg/g d. wt.) than that (2100μg/g d. wt.) observed in roots of wild type plants. We have demonstrated that Arabidopsis thaliana AtACR2 gene is a potential candidate for genetic engineering of plants to develop new crop cultivars that can be grown on arsenic contaminated fields to reduce arsenic content of the soil and can become a source of food containing no arsenic or exhibiting substantially reduced amount of this metalloid.
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| 10. |
- Nawani, Neelu, et al.
(författare)
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Status of metal pollution in rivers flowing through urban settlements at Pune and its effect on resident microflora
- 2016
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Ingår i: Biologia. - Bratislava : Springer. - 0006-3088 .- 1336-9563. ; 71:5, s. 494-507
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Tidskriftsartikel (refereegranskat)abstract
- This study illustrates the sporadic distribution of metals in fluvial systems flowing from catchments to urban settlements. This is a detailed study prognosticating the deteriorating quality of rivers at specific locations due to metal pollution. Heavy metals like cadmium, lead, nickel and mercury are prominent in industrial sector. Contour plots derived using spatial and temporal data could determine the focal point of metal pollution and its gradation. Metal values recorded were cadmium 157 mg/L, lead 47 mg/L, nickel 61 mg/L and mercury 0.56 mg/L. Prokaryote diversity was less in polluted water and it harboured metal tolerant bacteria, which were isolated from these polluted sites. Actinomycetes like Streptomyces and several other bacteria like Stenotrophomonas and Pseudomonas isolated from the polluted river sites exhibited changes in morphology in presence of heavy metals. This stress response offered remedial measures as Streptomyces were effective in biosorption of cadmium, nickel and lead and Stenotrophomonas and Pseudomonas were effective in the bioaccumulation of lead and cadmium. The amount of 89 mg of lead and 106 mg of nickel could be adsorbed on one gram of Streptomyces biomass-based biosorbent. Such biological remedies can be further explored to remove metals from polluted sites and from metal contaminated industrial or waste waters.
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