Högskolan i Skövde

Stevia is a perennial herb that belongs to the Asteraceae family. It is a natural sweetener plant and estimated to be 300 times sweeter than cane sugar. The leaves of stevia are the source of diterpene glycosides, viz. stevioside and rebaudioside. Stevioside is regenerated as a valuable natural sweetening agent because of its relatively good taste and chemical stability. Now it is being cultivated in Japan, Taiwan, Philippines, Hawaii, Malaysia and overall South America for food and pharmaceutical products. Products can be added to tea and coffee, cooked or baked goods, processed foods and beverages, fruit juices,

Arabidopsis thaliana is a small flowering plant belonging to the Brassicaceae family, which is adopted as a model plant for genetic research. Agrobacterium tumifaciensmediated transformation method for A. thaliana ecotype Bangladesh was established. Leaf discs of A. thaliana were incubated with A. tumefaciens strain LBA4404 containing chimeric nos. nptII. nos and intron-GUS genes. Following inoculation and co-cultivation, leaf discs were cultured on selection medium containing 50 mg/l kanamycin + 50 mg/l cefotaxime + 1.5 mg/l NAA and kanamycin resistant shoots were induced from the leaf discs after two weeks. Shoot regeneration was achieved after transferring the tissues onto fresh medium of the same combination. Finally, the shoots were rooted on MS medium containing 50 mg/l kanamycin. Incorporation and expression of the transgenes were confirmed by PCR analysis. Using this protocol, transgenic A. thaliana plants can be obtained and indicates that genomic transformation in higher plants is possible through insertion of desired gene. Although Agrobacterium mediated genetic transformation is established for A. thaliana, this study was the conducted to transform A. thaliana ecotype Bangladesh.

Background: Arsenic is a potent pollutant that has caused an environmental catastrophe in certain parts of the world including Bangladesh where millions of people are presently at risk due to drinking water contaminated by arsenic. Chronic arsenic exposure has been scientifically shown as a cause for liver damage, cancers, neurological disorders and several other ailments. The relationship between plasma cholinesterase (PChE) activity and arsenic exposure has not yet been clearly documented. However, decreased PChE activity has been found in patients suffering liver dysfunction, heart attack, cancer metastasis and neurotoxicity. Therefore, in this study, we evaluated the PChE activity in individuals exposed to arsenic via drinking water in Bangladesh.

Methods: A total of 141 Bangladeshi residents living in arsenic endemic areas with the mean arsenic exposure of 14.10 ± 3.27 years were selected as study subjects and split into tertile groups based on three water arsenic concentrations: low (< 129 μg/L), medium (130-264 μg/L) and high (> 265 μg/L). Study subjects were further sub-divided into two groups (≤50 μg/L and > 50 μg/L) based on the recommended upper limit of water arsenic concentration (50 μg/L) in Bangladesh. Blood samples were collected from the study subjects by venipuncture and arsenic concentrations in drinking water, hair and nail samples were measured by Inductively Coupled Plasma Mass Spectroscopy (ICP-MS). PChE activity was assayed by spectrophotometer.

Results: Arsenic concentrations in hair and nails were positively correlated with the arsenic levels in drinking water. Significant decreases in PChE activity were observed with increasing concentrations of arsenic in water, hair and nails. The average levels of PChE activity in low, medium and high arsenic exposure groups were also significantly different between each group. Lower levels of PChE activity were also observed in the > 50 μg/L group compared to the ≤50 μg/L group. Moreover, PChE activity was significantly decreased in the skin (+) symptoms group compared to those without (-).

Conclusions: We found a significant inverse relationship between arsenic exposure and PChE activity in a human population in Bangladesh. This research demonstrates a novel exposure-response relationship between arsenic and PChE activity which may explain one of the biological mechanisms through which arsenic exerts its neuro-and hepatotoxicity in humans.

Leaves, stem, roots and inflorescence of Solanum torvum Sw. were extracted in two different organic solvents (chloroform & methanol). Antibacterial and antifungal effects of the extracts were tested on fifteen (six Gram positive & nine Gram negative) human  pathogenic  bacteria  and  on  eight  pathogenic  fungi.  Methanolic  extracts  of  roots  of  S.  torvum  exhibited  promising antibacterial  and  antifungal  effects  on  all  organisms  tested  in  comparison  with  that  observed  in  the  leaves,  stems  and inflorescence extracts. The toxicity of the extracts was in the following order; root>stem>inflorescence>leaf. The minimum inhibitory concentration (MIC) values of methanolic extract of roots of S. torvum were in the range between 64-128 µg mL -1 . Chloroform  extracts  of  roots  were  more  toxic  (LC 50  35.4629  ppm)  than  other  extracts  analyzed  in  Brine  shrimp  test.  In conclusion, S. torvum appears to be an attractive material for the development of antimicrobial drugs and environment friendly biopesticides.

With a view to select divergent parents genetic diversity was estimated among twenty genotypes. Thirty F1 progenies developed by line-tester mating were studied from seedling generation to first clonal generation for five important agronomic traits. Cluster analysis reveals that the parents could be grouped into seven different clusters. Cluster means showed wide range of variation for several traits among singles as well as multi genotypic clusters. Considering diversity pattern, parents should select from cluster I, III, IV, and V for the improvement of potato. Analysis of variance revealed that all most all the sources of variation were highly significant for all the studied traits in both generations. Parents Challisha, Lalpakri, Patnai, Chamak, Sadagoti, TPS-67 and TPS-364 were found to be good general combiners for tuber yield and yield contribution traits due to their gca effects. The sca effects showed that out of 30 hybrids 12 were found to have specific combining ability for tuber yield and those hybrids also exhibited considerable heterosis for tuber yield and yield contributing traits.

Abscission is an active process that enables plants to shed unwanted organs. Because the purpose of the flower is to facilitate pollination, it often is abscised after fertilization. We have identified an Arabidopsis ethylene-sensitive mutant, inflorescence deficient in abscission (ida), in which floral organs remain attached to the plant body after the shedding of mature seeds, even though a floral abscission zone develops. The IDA gene, positioned in the genomic DNA flanking the single T-DNA present in the ida line, was identified by complementation. The gene encodes a small protein with an N-terminal signal peptide, suggesting that the IDA protein is the ligand of an unknown receptor involved in the developmental control of floral abscission. We have identified Arabidopsis genes, and cDNAs from a variety of plant species, that encode similar proteins, which are distinct from known ligands. IDA and the IDA-like proteins may represent a new class of ligands in plants

This study characterizes different MTP1 (metal tolerance protein)/ZAT (zinc transporter) homologs involved in zinc (Zn) homeostasis in plants. BLAST analysis of AtMTP1 protein against 15 plant species showed 21 MTP1 homologs. These MTP1 protein homologs generally contain ~400 residues, six transmembrane helices and cation transmembrane transporter activity (GO:0008324), which can be utilized in predicting Zn uptake and tolerance mechanisms. These MTP1 genes having 1 exon are located on chromosomes 2, 7, and 14. Motifs contain conserved sequences of 41–50 residues belonging to the cation efflux family, which may help target binding sites and transcription factors. Further, AtMTP1 shows close similarities with Glycine max and Medicago trunculata. Interactome analysis suggests the association of AtMTP1 with cadmium/zinc-transporting ATPase and ZIP metal ion transporter. The AtMTP1 network is predominantly connected to cadmium/zinc-transporting ATPase (heavy metal ATPase 2, HMA2; heavy metal ATPase 3, HMA3; heavy metal ATPase 4, HMA4), cation efflux protein (MTP11), and metal tolerance protein C3 (AT4G58060). The Genevestigator predicts the high expression potential of AtMTP1 in the apical root during senescence, seedling, and bolting stages in an association with 11 co-expressed genes, mainly linked to estradiol toxicity and heat stress. Besides, AtMTP1 protein homologs possess conserved N-glyco motifs and physicochemical properties. The similarity and interactions of AtMTP1 gene with other genes suggest that Zn homeostasis in plants is associated with the regulation of different genes. These findings may advance our understanding to further develop plants capable of maintaining Zn homeostasis under adverse conditions. © 2021 Elsevier Inc.

The current scenario of environmental pollution urges the need for an effective solution for toxic heavy metal removal from industrial wastewater. Bioremediation is the most cost effective process employed by the use of microbes especially bacteria resistant to toxic metals. In this study, Lysinibacillus sp. BA2, a nickel tolerant strain isolated from bauxite mine was used for the biosorption of Ni(II). Lysinibacillus sp. BA2 biomass had isoelectric point (pI) of 3.3. The maximum negative zeta potential value (−39.45) was obtained at pH 6.0 which was highly favourable for Ni(II) biosorption. 238.04 mg of Ni(II) adsorbed on one gram of dead biomass and 196.32 mg adsorbed on one gram of live biomass. The adsorption of Ni(II) on biomass increased with time and attained saturation after 180 min with rapid biosorption in initial 30 min. The Langmuir and Freundlich isotherms could fit well for biosorption of Ni(II) by dead biomass while Langmuir isotherm provided a better fit for live biomass based on correlation coefficient values. The kinetic studies of Ni(II) removal, using dead and live biomass was well explained by second-order kinetic model. Ni(II) adsorption on live biomass was confirmed by SEM-EDX where cell aggregation and increasing irregularity of cell morphology was observed even though cells were in non-growing state. The FTIR analysis of biomass revealed the presence of carboxyl, hydroxyl and amino groups, which seem responsible for biosorption of Ni(II). The beads made using dead biomass of Lysinibacillus sp. BA2 could efficiently remove Ni(II) from effluent solutions. These microbial cells can substitute expensive methods for treating nickel contaminated industrial wastewaters.

Rapid industrialization usually is the cause of increase in pollutants in the natural river bodies. This pollution is attributed to lack of improper treatment and inadequate disposal mechanisms of the waste generated thereof. The aim of present investigation was to screen actinomycetes for their ability to adsorb heavy metals. Actinomycetes belong to most diverse group of filamentous prokaryotes with ubiquitous presence in different ecological niches. This ubiquity is due to their ability to degrade almost any type of polymer and to use several compounds as carbon sources. Nearly 200 actinomycetes from different niches like fresh water, soda lake, geothermal springs, acid soils, etc from different locations in India were screened for ability to grow in presence of 1 to 5 mM of heavy metals like Cd, Hg, Pb, Ni, Sr, Fe, Mo, Zn and Mn. Most of the strains tolerant to heavy metals belonged to the genus Streptomyces spp. Five strains could grow in presence of 5 mM Cd²⁺, 4 strains in presence of 0.1 mM Hg²⁺, 18 strains in presence of 5 mM Pb²⁺, 21 strains in presence of 5 mM Ni²⁺, whereas 34 strains grew in presence of 5 mM Fe²⁺. One of the most promising strain was studied for its ability to absorb cadmium where 2x10¹¹ cells or spores could adsorb 0.32 mM to 0.33 mM of cadmium. Spores and vegetative cells showed nearly similar level of adsorbtion ability. This strain can be very useful in developing a bioreactor for the adsorption of heavy metals from industrial effluents containing cadmium.

RNA interference is a technique that has become popular in the past few years. This is a biological method to detect the activity of a specific gene within a cell. RNAi is the introduction of homologous double stranded RNA to specifically target a gene’s product resulting in null or hypomorphic phenotypes. This technique involves the degradation of specific mRNA by using small interfering RNA. Both microRNA (miRNA) and small interfering RNA (siRNA) are directly related to RNA interference. RNAi mechanism is being explored as a new technique for suppressing gene expression. It is an important issue in the treatment of various diseases. This review considers different aspects of RNAi technique including its history of discovery, molecular mechanism, gene expression study, advantages of this technique against previously used techniques, barrier associated with this technique, and its therapeutic application.

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.

N. spumigena is a dominant cyanobacterial species found in the Baltic Sea. It forms extensive bloom in late summer in the areas of the Baltic Sea with high phosphorus concentrations and moderate salinity. Both environmental and manmade factors are involved in bloom formation. This review also elucidates the physiological and molecular aspects of nitrogen fixation, heterocyst formation and nodularin production in N. spumigena.

Background: Chronic arsenic exposure has been shown to cause liver damage. However, serum hepatic enzyme activity as recognized on liver function tests (LFTs) showing a dose-response relationship with arsenic exposure has not yet been clearly documented. The aim of our study was to investigate the dose-response relationship between arsenic exposure and major serum enzyme marker activity associated with LFTs in the population living in arsenic-endemic areas in Bangladesh. Methods: A total of 200 residents living in arsenic-endemic areas in Bangladesh were selected as study subjects. Arsenic concentrations in the drinking water, hair and nails were measured by Inductively Coupled Plasma Mass Spectroscopy (ICP-MS). The study subjects were stratified into quartile groups as follows, based on concentrations of arsenic in the drinking water, as well as in subjects' hair and nails: lowest, low, medium and high. The serum hepatic enzyme activities of alkaline phosphatase (ALP), aspartate transaminase (AST) and alanine transaminase (ALT) were then assayed. Results: Arsenic concentrations in the subjects' hair and nails were positively correlated with arsenic levels in the drinking water. As regards the exposure-response relationship with arsenic in the drinking water, the respective activities of ALP, AST and ALT were found to be significantly increased in the high-exposure groups compared to the lowest-exposure groups before and after adjustments were made for different covariates. With internal exposure markers (arsenic in hair and nails), the ALP, AST and ALT activity profiles assumed a similar shape of dose-response relationship, with very few differences seen in the higher groups compared to the lowest group, most likely due to the temporalities of exposure metrics. Conclusions: The present study demonstrated that arsenic concentrations in the drinking water were strongly correlated with arsenic concentrations in the subjects' hair and nails. Further, this study revealed a novel exposure- and dose- response relationship between arsenic exposure metrics and serum hepatic enzyme activity. Elevated serum hepatic enzyme activities in the higher exposure gradients provided new insights into arsenic-induced liver toxicity that might be helpful for the early prognosis of arsenic-induced liver diseases.

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.

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.

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.

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.

Elevated exposure to arsenic has been suggested to be associated with atherosclerosis leading to cardiovascular disease (CVD). However, biochemical events underlying the arsenic-induced atherosclerosis have not yet been fully documented. The aim of this study was to investigate the associations of circulating molecules involved in atherosclerosis with arsenic exposure in the individuals exposed to arsenic in Bangladesh. A total of 324 study subjects, 218 from arsenic-endemic areas and 106 from nonendemic areas in Bangladesh, were recruited. Drinking water, hair, nail, and blood samples were collected from the study subjects for analysis. Total cholesterol (TC), low-density lipoprotein (LDL), and high-density lipoprotein (HDL) levels were lower in arsenic-endemic subjects than those of nonendemic subjects. Oxidized LDL (Ox-LDL), C-reactive protein (CRP), intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1) levels were significantly higher in arsenic-endemic subjects than those in nonendemic subjects. All these circulating molecules showed significant correlations with arsenic exposure (water, hair, and nail arsenic concentrations), and all these relations were significant before and after adjusting for relevant covariates. Among the circulating molecules tested in this study, HDL, Ox-LDL, and CRP showed dose-response relationships with arsenic exposure. Ox-LDL/ HDL ratios were increased with the increasing concentrations of arsenic in the water, hair, and nails. Furthermore, non-HDL cholesterol and TC/ HDL ratios were significantly correlated with arsenic exposure before and after adjusting for relevant covariates. Thus, all the observed associations may be the major features of arsenic exposure-related atherosclerosis leading to CVD.

Mutation in the wound-induced peptide transporter gene AtPTR3 (At5g46050) of Arabidopsis thaliana has been shown to affect germination on media containing a high salt concentration. The heterologous expression in yeast was utilized to verify that the AtPTR3 protein transports di-and tripeptides. The T-DNA insert in the Atptr3-1 mutant in the Arabidopsis ecotype C24 revealed two T-DNA copies, the whole vector sequence, and the gus marker gene inserted in the second intron of the AtPTR3 gene. An almost identical insertion site was found in the Atptr3-2 mutant of the Col-0 ecotype. The AtPTR3 expression was shown to be regulated by several signalling compounds, most clearly by salicylic acid (SA), but also methyl jasmonate (MeJA) and abscisic acid. Real-time PCR experiments suggested that the wound-induction of the AtPTR3 gene was abolished in the SA and JA signalling mutants. The Atptr3 mutant plants had increased susceptibility to virulent pathogenic bacteria Erwinia carotovora subsp. carotovora and Pseudomonas syringae pv. tomato, and produced more reactive oxygen species when grown on media containing paraquat or rose bengal. Public microarray data suggest that the AtPTR3 expression was induced by Pseudomonas elicitors and by avirulent P. syringae pathovars and type III secretion mutants. This was verified experimentally for the hrpA mutant with real-time PCR. These results suggest that AtPTR3 is one of the defence-related genes whose expression is reduced by virulent bacterium by type III dependent fashion. Our results suggest that AtPTR3 protects the plant against biotic and abiotic stresses.

A T-DNA tagged mutant line of Arabidopsis thaliana, produced with a promoter trap vector carrying a promoterless gus (uidA) as a reporter gene, showed GUS induction in response to mechanical wounding. Cloning of the chromosomal DNA flanking the T-DNA revealed that the insert had caused a knockout mutation in a PTR-type peptide transporter gene named At5g46050 in GenBank, here renamed AtPTR3. The gene and the deduced protein were characterized by molecular modelling and bioinformatics. Molecular modelling of the protein with fold recognition identified 12 transmembrane spanning regions and a large loop between the sixth and seventh helices. The structure of AtPTR3 resembled the other PTR-type transporters of plants and transporters in the major facilitator superfamily. Computer analysis of the AtPTR3 promoter suggested its expression in roots, leaves and seeds, complex hormonal regulation and induction by abiotic and biotic stresses. The computer-based hypotheses were tested experimentally by exposing the mutant plants to amino acids and several stress treatments. The AtPTR3 gene was induced by the amino acids histidine, leucine and phenylalanine in cotyledons and lower leaves, whereas a strong induction was obtained in the whole plant upon exposure to salt. Furthermore, the germination frequency of the mutant line was reduced on salt-containing media, suggesting that the AtPTR3 protein is involved in stress tolerance in seeds during germination.

1,25-Dihydroxyvitamin D₃ (1,25(OH)₂D₃) has been demonstrated to mediate both genomic and non-genomic responses in prostate cancer (CaP) cells. Here, we give an overview of membrane initiated 1,25(OH)₂D₃ signaling in prostate cancer cell progression. The presence of PDIA3 was investigated and homologous modeling of the putative PDIA3 receptor complex was conducted. Furthermore, the cellular distribution of nVDR was analyzed. We could show that both nVDR and PDIA3 are expressed in the prostate cancer cell lines investigated. The homologous modeling of PDIA3 showed that the receptor complex exists in a trimer formation, which suggests for allosteric activity. Our findings support previous reports and suggest that 1,25(OH)₂D₃ is an important therapeutic agent in inhibiting prostate cancer progression. Furthermore, our data show that 1,25(OH)₂D₃ regulate prostate cell biology via multiple pathways and targeting specific pathways for 1,25(OH)₂D₃ might provide more effective therapies compared to the vitamin D therapies currently clinically tested.

Contamination of food with arsenics is a potential health risk for both humans and animals in many regions of the world, especially in Asia. Arsenics can be accumulated in humans, animals and plants for a longer period and a long-term exposure of humans to arsenics results in severe damage of kidney, lever, heart etc. and many other vascular diseases. Arsenic contamination in human may also lead to development of cancer. In this paper we report our results on data mining approach (an in silico analysis based on searching of the existing genomic databases) for identification and characterization of genes that might be responsible for uptake, accumulation or metabolism of arsenics. For these in silico analyses we have involved the model plant Arabidopsis thaliana in our investigation. By employing a system biology model (a kinetic model) we have studied the molecular mechanisms of these processes in this plant. This model contains equations for uptake, metabolism and sequestration of different types of arsenic; As(V), As(III), MMAA and DMAA. The model was then implemented in the software XPP. The model was also validated against the data existing in the literatures. Based on the results of these in silico studies we have developed some strategies that can be used for reducing arsenic contents in different parts of the plant. Data mining experiments resulted in identification of two candidate genes (ACR2, arsenate reductase 2 and PCS1, phytochelatin synthase 1) that are involved either in uptake, transport or cellular localization of arsenic in A. thaliana. However, our system biology model revealed that by increasing the level of arsenate reductase together with an increased rate of arsenite sequestration in the vacuoles (by involving an arsenite efflux pump MRP1/2), it is possible to reduce the amount of arsenics in the shoots of A. thaliana to 11–12%.

The HIV/AIDS epidemic kills about 2.1 million people around the world every year. Unfortunately, until now attempts to control and diminish further spread of the disorder have resulted in very limited success. Although highly active antiretroviral therapy (HAART) is now available as a treatment option, the rate of its success is limited because of drug resistance. In this context, a more efficient treatment is very much necessary to fight with this fatal disease. The RNA interference (RNAi) can be employed as one of the powerful methods for treatment of the disease as it can effectively silence gene expression in a sequence specific manner. The RNAi-mediated treatment is therefore a promising substitution for therapy of the global epidemic HIV/AIDS in the future. The main objective of this review is to focus on an in-depth analysis of RNAi and the principles underlying RNAi treatment, and it's also described the molecular mechanisms of HIV infection, current treatment facilities available to patients as well as therapeutic applications of RNAi along with their limitations as to why the options are inadequate to give a safe and sound cure of HIV/AIDS.

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.

Rice growing regions plagued by arsenic-contaminated soils and irrigation water do not have a viable option for producing arsenic-free crops. For instance, in Bangladesh every year more than 30 million people are affected from rice-derived arsenic contamination that contributes to arsenic levels known to cause health-related illnesses. Our strategy is to genetically-modify molecular mechanisms involved in the localization of arsenic to divert it to the non-edible parts of the plant. To identify viable candidate genes, we employed data mining, an in silico analysis based on searching existing genomic databases and in the genetic model plant Arabidopsis thaliana. To assist our investigation, we constructed a kinetic model to outline strategies for developing genetically-modified plants exhibiting a significant reduction in arsenic concentration in the edible parts (straw and grain). This model contains equations for uptake, metabolism and sequestration of different types of arsenic (As (V), As (III), MMAA and DMAA). The model was implemented using XPP and validated against existing data from the literature. From these analysis, we identified four candidate genes that are involved either in uptake, transport or cellular localization of arsenic in plants. But we found only one gene implicated in arsenic metabolism in rice. In parallel, we identified available T-DNA insertion mutants to determine the effects of these genes on arsenic accumulation. Results obtained from in silico data-mining, kinetic modeling, and assays with T-DNA insertion mutants will be used to design gene cloning experiments to study the target genes in yeast, E. coli and Arabidopsis heterologous systems. Upon confirmation of the effectiveness of these candidates, vectors containing the target genes will be constructed for transformation into rice. The new rice varieties produced will be tested under field conditions to assess their effectiveness at reducing or eliminating arsenic from the edible parts of the rice plant.

Exposure to toxic metals alters host response and that leads to disease development. Studies have revealed the effects of metals on microbial physiology, however, the role of metal resistant bacteria on host response to metals is unclear. The hypothesis that xenobiotic interactions between gut microbes and arsenic influence the host physiology and toxicity was assessed in a Caenorhabditis elegans model. The arsenic-resistant Lysinibacillus sphaericus B1CDA was fed to C. elegans to determine the host responses to arsenic in comparison to Escherichia coli OP50 food. L. sphaericus diet extended C. elegans lifespan compared to E. coli diet, with an increased expression of genes involved in lifespan, stress response and immunity (hif-1, hsp-16.2, mtl-2, abf-2, clec-60), as well as reduced fat accumulation. Arsenic-exposed worms fed L. sphaericus also had a longer lifespan than those fed E. coli and had an increased expression of genes involved in cytoprotection, stress resistance (mtl-1, mtl-2) and oxidative stress response (cyp-35A2, isp-1, ctl-2, sod-1), together with a decreased accumulation of reactive oxygen species (ROS). In comparison with E. coli, L. sphaericus B1CDA diet increased C. elegans fitness while detoxifying arsenic induced ROS and extending lifespan.

Extensive use of chromium, cadmium and lead nitrate in tanning industry has caused substantial environmental pollution in Bangladesh. Bioremediation of tanning effluents with the help of bacteria was investigated. Samples of effluents with cadmium, chromium and lead nitrate (10mg/ml) were incubated in mineral salt medium at 37°C for 4 days and bacterial strain was isolated from the sample. Preliminary characterization of the organisms according to Bergey's manual suggests that the organisms may belong to Coccus species. The rate of reduction of these effluents was determined by using the flame Atomic Absorption Spectrophotometer (AAS). Out of 3 ppm concentration the rates of reduction were found to be 2.96 ppm for chromium; 2.92 ppm for cadmium and 2.46 ppm for lead nitrate. The isolated bacteria harboured three endogenous plasmids. All of the plasmids were lost when the organisms were treated with ethidium bromide (100mg/ml). Loss of the plasmids resulted in disability of the bacteria to grow on media containing chromium, cadmium and lead-nitrate. Phenotypic testing of wild type and cured strains revealed that the gene(s) responsible for chromium, cadmium and lead-nitrate degradation may reside upon the plasmids.

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.

This paper reports a continuation of our previous research on the phytochelatin synthase1 (PCS1) gene involved in binding and sequestration of heavy metals or metalloids in plant cells. Construction of a 3D structure of the Arabidopsis thaliana PCS1 protein and prediction of gene function by employing iterative implementation of the threading assembly refinement (I-TASSER) revealed that PC ligands (3GC-gamma-glutamylcysteine) and Gln50, Pro53, Ala54, Tyr55, Cys56, Ile102, Gly161, His162, Phe163, Asp204 and Arg211 residues are essential for formation of chelating complex with cadmium (Cd²⁺) or arsenite (AsIII). This finding suggests that the PCS1 protein might be involved in the production of the enzyme phytochelatin synthase, which might in turn bind, localize, store or sequester heavy metals in plant cells. For validation of the in silico results, we included a T-DNA tagged mutant of Arabidopsis thaliana, SAIL_650_C12, (mutation in AtPCS1 gene) in our investigation. Furthermore, using reverse transcriptase PCR we confirmed that the mutant does not express the AtPCS1 gene. Mutant plants of SAIL_650_C12 were exposed to various amounts of cadmium (Cd²⁺) and arsenite (AsIII) and the accumulation of these toxic metals in the plant cells was quantified spectrophotometrically. The levels of Cd²⁺ and AsIII accumulation in the mutant were approximately 2.8 and 1.6 times higher, respectively, than that observed in the wild-type controlled plants. We confirmed that the results obtained in in silico analyses complement those obtained in in vivo experiments.

Previously, our in silico analyses identified four candidate genes that might be involved in uptake and/or accumulation of arsenics in plants: arsenate reductase 2 (ACR2), phytochelatin synthase 1 (PCS1) and two multi-drug resistant proteins (MRP1 and MRP2) [Lund et al. (2010) J Biol Syst 18:223–224]. We also postulated that one of these four genes, ACR2, seems to play a central role in this process. To investigate further, we have constructed a 3D structure of the Arabidopsis thaliana ACR2 protein using the iterative implementation of the threading assembly refinement (I-TASSER) server. These analyses revealed that, for catalytic metabolism of arsenate, the arsenate binding-loop (AB-loop) and residues Phe-53, Phe-54, Cys-134, Cys-136, Cys-141, Cys-145, and Lys-135 are essential for reducing arsenate to arsenic intermediates (arsenylated enzyme-substrate intermediates) and arsenite in plants. Thus, functional predictions suggest that the ACR2 protein is involved in the conversion of arsenate to arsenite in plant cells. To validate the in silico results, we exposed a transfer-DNA (T-DNA)-tagged mutant of A. thaliana (mutation in the ACR2 gene) to various amounts of arsenic. Reverse transcriptase PCR revealed that the mutant exhibits significantly reduced expression of the ACR2 gene. Spectrophotometric analyses revealed that the amount of accumulated arsenic compounds in this mutant was approximately six times higher than that observed in control plants. The results obtained from in silico analyses are in complete agreement with those obtained in laboratory experiments.

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.

Actinomycetes, one of the most diverse groups of filamentous bacteria, are well recognized for their metabolic versatility. The bioactive potential of these bacteria facilitates their survival even in distress and unfavourable ecological conditions. This special issue is dedicated to the importance of multitude of primary and secondary metabolites produced by actinomycetes. The importance of large repertory of enzymes from actinomycetes and their potential in replacing chemical catalysts is discussed.

Microbial technologies play an extremely crucial role in wastewater treatment. In the last few decades, the focus was on wastewater treatment; however, with the consumption of already finite resources, this focus has now shifted to wastewater remediation and recycling. The latest technologies are more robust at wastewater treatment and the recovery of useful compounds from the wastewaters. This chapter compiles the latest technologies in which microbial/bacterial biomass was used for wastewater treatment and remediation. This chapter also gives a special focus on remediation of wastewaters contaminated with heavy metals, describing the basic technologies as well as smart technologies. Emphasis is given to circular bioeconomy and how it can be implemented in wastewater treatment. A circular model incorporating key areas such as point source detection of pollutants, characterization of wastewaters, choice of the remedial technology, and type of treatment is explained in the chapter.

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.

Rhizobium spp. was isolated from root nodules of Pigeon pea (Cajanus cajan L.), Sweet pea (Lathyrus sativus L.), Chickpea (Cicer arietinum L.). The isolates ware rod shaped, aerobic, gram negative, motile and non-spore forming. Isolates were positive to Catalase, Citrate utilization, Urea hydrolysis, Congored, Nitrification, Oxidase, Triple sugar iron and MacConkey agar test. The isolates can ferment all nine sugars. Then, the isolates identified as Rhizobium spp. Depending on above results were subjected to 16S rRNA sequencing for further confirmation and identification. Surprisingly, theisolates were same strain or member of same cluster of Rhizobium and identified as Rhizobium sp.CCNWYC119 strain based on 16S rRNA sequence (98% similarity). Then, different parameters of soil quality enrichment and plant growth viz.plant height; weight of pods and seeds; number, fresh and dry weight of nodules were studied to test the efficacy of the isolate as biofertilizer. Here, inoculant of Rhizobium sp. isolated from Pigeon pea was used as biofertilizer. The results showed the significant increase of nodulation, enrichment of soil of rhizosphere, plant growth and yield for all three types of inoculated peas as compared with non-inoculated control peas indicating that the isolated strain could be used as a common efficient biofertilizer for Pigeon pea, Sweet pea and Chick pea. It was also found that the isolate grew optimally at temperature 28°C and pH 7.0.Moreover, the isolate was sensitive to the higher concentration of NaCl (>1%) and to antibiotics- Mecillinam, Ciprofloxacin,Cotrimoxazole, Pefloxacin, Ceftazidime and Tetracycline.

Biocatalysis, one of the oldest technologies, is becoming a favorable alternative to chemical processes and a vital part of green technology. It is an important revenue generating industry due to a global market projected at $7 billion in 2013 with a growth of 6.7% for enzymes alone. Some microbes are important sources of enzymes and are preferred over sources of plant and animal origin. As a result, more than 50% of the industrial enzymes are obtained from bacteria. The constant search for novel enzymes with robust characteristics has led to improvisations in the industrial processes, which is the key for profit growth. Actinomycetes constitute a significant component of the microbial population in most soils and can produce extracellular enzymes which can decompose various materials. Their enzymes are more attractive than enzymes from other sources because of their high stability and unusual substrate specificity. Actinomycetes found in extreme habitats produce novel enzymes with huge commercial potential. This review attempts to highlight the global importance of enzymes and extends to signify actinomycetes as promising harbingers of green technology.

The developing paradigms about YKL-40, a member of the "mammalian chitinase-like proteins", from across the globe, project it as a vital parameter for the detection of disease onset and progression. It is expressed and secreted by cancer cells of different origins along with a variety of non-malignant cells including inflammatory and structural cells. Numerous studies demonstrate that YKL-40 over-expression is associated with increased patient mortality though the cellular receptors responsible for mediating these effects have not yet been identified. The putative YKL-40 ligands are thought to be carbohydrate structures, since it is capable of binding chitin, chito-oligosaccharides and heparin. Binding of collagen to YKL-40, identified it as the only non-carbohydrate extracellular matrix (ECM) ligand for YKL-40. Our broad understanding of YKL-40 as a versatile biomarker and its involvement in activating several signaling pathways make us anticipate that its specific receptors/binding partners may exist on the cell surface also. The cell surface heparan sulfate (HS) moieties seem to be the potential candidates for this role, suggesting that it could interact with HS-proteoglycans. It is recommended to clearly delineate YKL-40-mediated signaling mechanisms before promoting the YKL-40 know-how for translational research, in both diagnostic and therapeutic applications. The present review provides an overview of YKL-40 as a versatile biomarker, discussing the related pathological mechanisms and aims to reassess and unify the already proposed diverse hypotheses in YKL-40-regulated signaling mechanisms. (c) 2013 Elsevier Inc. All rights reserved.

Here, we report the genomic sequence and genetic composition of an arsenic resistant bacterium Lysinibacillus sphaericus B1-CDA. Assembly of the sequencing reads revealed that the genome size is ~4.5 Mb encompassing ~80% of the chromosomal DNA.

The main objective of this study was to identify and isolate arsenic resistant bacteria that can be used for removing arsenic from thecontaminated environment. Here we report a soil borne bacterium, B1-CDA that can serve this purpose. B1-CDA was isolated fromthe soil of a cultivated land in Chuadanga district located in the southwest region of Bangladesh. The morphological, biochemicaland 16S rRNA analysis suggested that the isolate belongs to Lysinibacillus sphaericus. The minimum inhibitory concentration (MIC)value of the isolate is 500 mM (As) as arsenate. TOF-SIMS and ICP-MS analysis confirmed intracellular accumulation and removalof arsenics. Arsenic accumulation in cells amounted to 5.0 mg g¡1 of the cells dry biomass and thus reduced the arsenicconcentration in the contaminated liquid medium by as much as 50%. These results indicate that B1-CDA has the potential forremediation of arsenic from the contaminated water. We believe the benefits of implementing this bacterium to efficiently reducearsenic exposure will not only help to remove one aspect of human arsenic poisoning but will also benefit livestock and native animalspecies. Therefore, the outcome of this research will be highly significant for people in the affected area and also for humanpopulations in other countries that have credible health concerns as a consequence of arsenic-contaminated water.

Previously, we reported an arsenic resistant bacterium Lysinibacillus sphaericus B1-CDA, isolated from an arsenic contaminated lands. Here, we have investigated its genetic composition and evolutionary history by using massively parallel sequencing and comparative analysis with other known Lysinibacillus genomes. Assembly of the sequencing reads revealed a genome of ~ 4.5 Mb in size encompassing ~ 80% of the chromosomal DNA. We found that the set of ordered contigs contains abundant regions of similarity with other Lysinibacillus genomes and clearly identifiable genome rearrangements. Furthermore, all genes of B1-CDA that were predicted be involved in its resistance to arsenic and/or other heavy metals were annotated. The presence of arsenic responsive genes was verified by PCR in vitro conditions. The findings of this study highlight the significance of this bacterium in removing arsenics and other toxic metals from the contaminated sources. The genetic mechanisms of the isolate could be used to cope with arsenic toxicity.

This study is a part of our long term project on bioremediation of toxic metals and other pollutants for protection of human health and the environment from severe contamination. The information and results presented in this data article are based on both in vitro and in silico experiments. In vitro experiments were used to investigate the presence of arsenic responsive genes in a bacterial strain B1-CDA that is highly resistant to arsenics. However, in silico studies were used to annotate the function of the metal responsive genes. By using this combined study consisting of in vitro and in silico experiments we have identified and characterized specific genes from B1-CDA that can be used as a potential tool for removal of arsenics as well as other heavy metals from the contaminated environment.

Chromium and chromium containing compounds are discharged into the nature as waste from anthropogenic activities, such as industries, agriculture, forest farming, mining and metallurgy. Continued disposal of these compounds to the environment leads to development of various lethal diseases in both humans and animals. In this paper, we report a soil borne bacterium, B2-DHA that can be used as a vehicle to effectively remove chromium from the contaminated sources. B2-DHA is resistant to chromium with a MIC value of 1000 µg/mL potassium chromate. The bacterium has been identified as a Gram negative, Enterobacter cloacae based on biochemical characteristics and 16S rRNA gene analysis. TOF-SIMS and ICP-MS analyses confirmed intracellular accumulation of chromium and thus its removal from the contaminated liquid medium. Chromium accumulation in cells was 320 µg/g of cells dry biomass after 120 h exposure and thus it reduced the chromium concentration in the liquid medium by as much as 81%. Environmental scanning electron micrograph revealed the effect of metals on cellular morphology of the isolates. Altogether, our results indicate that B2-DHA has the potential to reduce chromium significantly to safe levels from the contaminated environments and suggest the potential use of this bacterium in reducing human exposure to chromium, hence avoiding poisoning.

In this chapter, arsenic-accumulating and arsenic- transformingbacterial strains that can be employed as a sourcefor cost-effective and eco-friendly bioremediation of arsenicsfrom contaminated environments have been reviewed. Thischapter demonstrates that many naturally occurring bacterialstrains like B1-CDA have the potential for reducing arseniccontent in contaminated sources to safe levels. Therefore,the socioeconomic impact of this kind of microorganisms ishighly significant for those countries, especially in the developingworld, where impoverished families and villages aremost impacted. Therefore, this discovery should be consideredto be the most significant factor in formulating nationalstrategies for effective poverty elimination. Besides humanarsenic contamination, these bacterial strains will also benefitlivestock and native animal species, and the outcome ofthese studies is vital not only for people in arsenic-affectedareas but also for human populations in other countries thathave credible health concerns as a consequence of arseniccontaminatedwater and foods.

Previously, we reported a chromium-resistant bacterium, Enterobacter cloacae B2-DHA, isolated from the landfills of tannery industries in Bangladesh. Here, we investigated its genetic composition using massively parallel sequencing and comparative analysis with other known Enterobacter genomes. Assembly of the sequencing reads revealed a genome of ~4.21 Mb in size.

The previously described chromium resistant bacterium, Enterobacter cloacae B2-DHA, was isolated from leather manufacturing tannery landfill in Bangladesh. Here we report the entire genome sequence of this bacterium containing chromium and other heavy metal resistance genes. The genome size and the number of genes, determined by massive parallel sequencing and comparative analysis with other known Enterobacter genomes, are predicted to be 4.22 Mb and 3958, respectively. Nearly 160 of these genes were found to be involved in binding, transport, and catabolism of ions as well as efflux of inorganic and organic compounds. Specifically, the presence of two chromium resistance genes, chrR and chrA was verified by polymerase chain reaction. The outcome of this research highlights the significance of this bacterium in bioremediation of chromium and other toxic metals from the contaminated sources.

The aim of this study was to evaluate the protective effect of Zingiber zerumbet Linn powder on sodium arsenite-induced changes of blood indices in experimental mice. Swiss albino male mice were divided into four groups. The first group was used as control, while the second, third and fourth groups were treated with Z. zerumbet (L.) powder, sodium arsenite and Z. zerumbet (L.) powder plus sodium arsenite, respectively. Animals (third and fourth groups) were exposed to sodium arsenite at a dose of 10 mg/kg body weight/day for 12 weeks. Exposure to sodium arsenite revealed a significant (p < 0.05) increase of serum urea, uric acid, triglyceride (TG), glucose levels and alkaline phosphatase (ALP) activity. Serum butyryl cholinesterase (BChE) activity significantly (p < 0.05) decreased in sodium arsenite-treated group as compared with control group. Interestingly, food supplemented with Z. zerumbet (L.) (50 mg/kg body weight/day) showed protective effect against sodium arsenite-induced increase of serum urea, uric acid and TG levels except serum glucose levels. Moreover, Z. zerumbet (L.) also abrogated the sodium arsenite-induced changes of BChE and ALP activities. Therefore, the ameliorating effects of Z. zerumbet (L.) on sodium arsenite-treated mice suggested the future application of Z. zerumbet (L.) to reduce or prevent arsenic toxicity in human.

Mercury (Hg) is toxic to plants, but the effect of glutathione in Hg alleviation was never studied in alfalfa, an important forage crop. In this study, Hg toxicity showed morphological retardation, chlorophyll reduction, and PSII inefficiency, which was restored due to GSH supplementation in alfalfa plants treated with Hg. Results showed a significant increase of Hg, but Fe and S concentrations substantially decreased in root and shoot accompanied by the downregulation of Fe (MsIRT1) and S (MsSultr1;2 and MsSultr1;3) transporters in roots of Hg-toxic alfalfa. However, GSH caused a significant decrease of Hg in the shoot, while the root Hg level substantially increased, accompanied by the restoration of Fe and S status, relative to Hg-stressed alfalfa. The subcellular analysis showed a substantial deposition of Hg in the root cell wall accompanied by the increased GSH and PC and the upregulation of MsPCS1 and MsGSH1 genes in roots. It suggests the involvement of GSH in triggering PC accumulation, causing excess Hg bound to the cell wall of the root, thereby reducing Hg translocation in alfalfa. Bioinformatics analysis showed that the MsPCS1 protein demonstrated one common conserved motif linked to the phytochelatin synthase domain (CL0125) with MtPCS1 and AtMCS1 homologs. These in silico analysis further confirmed the detoxification role of MsPCS1 induced by GSH in Hg-toxic alfalfa. Additionally, GSH induces GSH and GR activity to counteract oxidative injuries provoked by Hg-induced H2O2 and lipid peroxidation. These findings may provide valuable knowledge to popularize GSH-derived fertilizer or to develop Hg-free alfalfa or other forage plants. 

An in vitro propagation of a red Gerbera (Gerbera jamesonii) variety was achieved by culturing flower bud, leaf segments and flower stalk segments of 80 days old field grown plants on Murashige and Skoog (MS) medium supplemented with different concentration (1.0-6.0 mg/l) of 6-benzyl adenine (BA) in combination with single concentration (1.0 mg/l) of α-naphthalene acetic acid (NAA). Lower concentration of BA (1.0 and 2.0 mg/l) with NAA induced the explants to form callus. On the other hand when the explants were cultured in higher concentration (5.0 mg/l) of BA produced shoots and 5.0 mg/l BA with 1.0 mg/l NAA was found to be the best for shoot proliferation of the three explants optimum response was obtained from flower buds. Further multiplication of shoots occurred upon transfer of shoot clumps to BA containing MS medium. Regenerated shoots were rooted in MS medium with indole-3-acetic acid (IAA) or indole-3-buteric acid (IBA) and maximum frequency (81%) of rooting with highest number (4) of roots per shoot was achieved in MS medium fortified with 0.3 mg/l IBA. The rooted shoots were acclimatized and successfully established in soil under natural environment with maximum 84% survivability.