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1.
Article in English | MEDLINE | ID: mdl-33909547

ABSTRACT

A Gram-stain-positive, strictly aerobic, spore-forming, rod-shaped and non-motile bacterium designated strain SIJ1T was obtained from tidal flat sediment collected from the northern shore of Kuwait Bay, northwest of the Arabian Gulf. Strain SIJ1T grew optimally at 30 °C and pH 7-8 in the presence of 6 % (w/v) NaCl. The cell-wall peptidoglycan was based on meso-diaminopimelic acid and an unsaturated menaquinone with seven isoprene units (MK-7) was the predominant respiratory quinone. It contained anteiso-C15 : 0, iso-C16 : 0 and iso-C15 : 0 as the major fatty acids and ribose as the major whole-cell sugar. The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, unidentified phospholipid, an unidentified glycolipid, phosphoglycolipid and an unidentified lipid. Phylogenetic analysis based on 16S rRNA genes revealed that SIJ1T showed a distinct evolutionary lineage within the Firmicutes. The DNA G+C content was 43.1 mol% and the full genome analysis for strain SIJ1T showed that it had a genome size of 3 989 945 bp and contained 4085 predicted protein-encoding genes. The SIJ1T annotated genome showed more stress resistance encoding genes in comparison to its closely related strains. The amino acid identity and average nucleotide identity data for the whole genome proved that strain SIJ1T does indeed represent a novel genus. The strain was distinguishable from the phylogenetically related genera through differences in several phenotypic properties. On the basis of the phenotypic, phylogenetic and genetic data, strain SIJ1T represents a novel genus and species in the family Bacillaceae, for which the name Litoribacterium kuwaitense gen. nov., sp. nov. is proposed. The type strain is SIJ1T (=DSM 28862T=LMG 28316T).


Subject(s)
Geologic Sediments/microbiology , Phylogeny , Seawater/microbiology , Bacillaceae/classification , Bacterial Typing Techniques , Base Composition , Bays , Cell Wall/chemistry , DNA, Bacterial/genetics , Diaminopimelic Acid/chemistry , Fatty Acids/chemistry , Glycolipids/chemistry , Kuwait , Peptidoglycan/chemistry , Phospholipids/chemistry , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , Vitamin K 2/analogs & derivatives , Vitamin K 2/chemistry
2.
Int J Phytoremediation ; 22(11): 1137-1146, 2020.
Article in English | MEDLINE | ID: mdl-32212968

ABSTRACT

Uranium uptake, translocation and its effects on leaf anatomy in vetiver grass (Vetiveria zizanioides L. Nash) grown in hydroponics were investigated at a wide range of concentrations. At concentrations below 200 ppm (1, 5, 25, 100, and 200 ppm) almost 90-95% of uranium was depleted from the medium within 3 days of treatment, while at other concentrations viz., at 318, 500, 619, 1,000, 5,000, 7,500, and 11,900 ppm, it reached a maximum between 7 and 14 days, with a marginal increase in the depletion thereafter. Most of the uranium could be recovered from plants at concentrations below 200 ppm. On the contrary, a significant reduction in the recovery of uranium was noticed at higher concentrations and the percentage of recovery dropped from 82% at 318 ppm to 35% at 11,900 ppm. While most of the uranium taken up by the plants could be recovered from roots at lower concentrations, a preferential translocation of the element to shoot occurred at concentrations beyond 1,000 ppm. Histological studies of leaves from plants treated with 1,000 ppm uranium displayed the formation of multilayered cells between the epidermis and vascular bundles on the adaxial side in the distal regions of the leaves. The plants were also found to tolerate and survive the radiological and chemical constituents of both uranium mill tailings soil as well as various effluents of uranium mine and mill operations. Further, they could also survive in uranium ore containing 600 ppm of triuranium octoxide (U3O8) and could withstand the amendment of ore with citric acid. The ability of vetiver to take up uranium from solutions to high levels and its survival in effluents, mill tailings soil, and ore coupled with its ecological characteristics makes it an ideal plant for phytoextraction of uranium.


Subject(s)
Chrysopogon , Soil Pollutants/analysis , Uranium , Biodegradation, Environmental , Hydroponics
3.
Article in English | MEDLINE | ID: mdl-33629941

ABSTRACT

A Gram-stain-negative, rod and rod-curved shaped motile bacterium designated strain S25T was obtained from benthic sediment collected near the Kubbar Island coral reefs south of Kuwait. Phenotypic analysis revealed that strain S25T was slightly halophilic, mesophilic and facultative anaerobic, fermenting d-glucose, d-ribose, d-mannose, d-mannitol, maltose, fructose, gentiobiose, cellobiose, melibiose, trehalose and sucrose. It was positive for oxidase and indole production and negative for arginine dihydrolase and lysine and ornithine decarboxylases. It contained C16 : 1 ω7c/C16 : 1 ω6c (summed feature 3), C18 : 1 ω7c (summed feature 8) and C16 : 0 as the major fatty acids. Strain S25T grew optimally at 30 °C and pH 8 in the presence of 3 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA sequences revealed that strain S25T is related to species of the genus Grimontia, having 99.15 % similarity to 'Grimontia indica' AK16T, 99.08 % to Grimontia celer 96-237T and 98.66 % to Grimontia marina IMCC 5001T. The DNA G+C content was 48.8 mol% and the full genome analysis for the strain S25T showed that the bacterium has a genome size of 5 158 621 bp and contains 4730 predicted protein-encoding genes. The average nucleotide identity values between the S25T genome and the genomes of its nearest matches ranged between 81.39 and 94.16 %. The strain was distinguishable from the phylogenetically related genera through differences in several phenotypic properties. On the basis of the phenotypic, phylogenetic and genetic data, strain S25T represents a novel species in the genus Grimontia, for which the name Grimontia sedimenti sp. nov. is proposed. The type strain of Grimontia sedimenti is S25T (=DSM 28878T=LMG 28315T).

4.
Physiol Mol Biol Plants ; 22(1): 69-76, 2016 Jan.
Article in English | MEDLINE | ID: mdl-27186020

ABSTRACT

An endochitinase gene 'ech42' from the biocontrol fungus 'Trichoderma virens' was introduced to Brassica juncea (L). Czern and Coss via Agrobaterium tumefaciens mediated genetic transformation method. Integration and expression of the 'ech42' gene in transgenic lines were confirmed by PCR, RT-PCR and Southern hybridization. Transgenic lines (T1) showed expected 3:1 Mendelian segregation ratio when segregation analysis for inheritance of transgene 'hpt' was carried out. Fluorimetric analysis of transgenic lines (T0 and T1) showed 7 fold higher endochitinase activity than the non-transformed plant. Fluorimetric zymogram showed presence of endochitinase (42 kDa) in crude protein extract of transgenic lines. In detached leaf bioassay with fungi Alternaria brassicae and Alternaria brassicicola, transgenic lines (T0 and T1) showed delayed onset of lesions as well as 30-73 % reduction in infected leaf area compared to non-transformed plant.

5.
J Biotechnol ; 161(4): 422-8, 2012 Nov 15.
Article in English | MEDLINE | ID: mdl-22898176

ABSTRACT

Phytoremediation is a viable strategy for management of toxic wastes in a large area/volume with low concentrations of toxic elemental pollutants. With increased industrial use of cobalt and its alloys, it has become a major metal contaminant in soils and water bodies surrounding these industries and mining sites with adverse effects on the biota. A bacterial Co-Ni permease was cloned from Rhodopseudomonas palustris and introduced into Nicotiana tabacum to explore its potential for phytoremediation and was found to be specific for cobalt and nickel. The transgenic plants accumulated more cobalt and nickel as compared to control, whereas no significant difference in accumulation of other divalent ions was observed. The transgenic plants were evaluated for cobalt content and showed increased acquisition of cobalt (up to 5 times) as compared to control. The plants were also assessed for accumulation of nickel and found to accumulate up to 2 times more nickel than control. At the same initial concentration of cobalt and nickel, transgenic plant preferentially accumulated cobalt as compared to nickel. The present study is perhaps the first attempt to develop transgenic plants expressing heterologous Co transporter with an improved capacity to uptake cobalt.


Subject(s)
Bacterial Proteins/genetics , Cobalt/metabolism , Membrane Transport Proteins/genetics , Nicotiana/metabolism , Bacterial Proteins/metabolism , Biodegradation, Environmental , Membrane Transport Proteins/metabolism , Nickel/metabolism , Plant Roots/metabolism , Plant Shoots/metabolism , Plants, Genetically Modified , Nicotiana/genetics
6.
Nat Prod Res ; 25(18): 1762-5, 2011 Oct.
Article in English | MEDLINE | ID: mdl-21899480

ABSTRACT

Camptothecin (CPT), the derivatives of which are used clinically for the treatment of metastatic colon cancer, is isolated from intact plants that can be subjected to environmental fluctuations. In vitro cultures may be an alternate and continuous source for year-round production of CPT. Since CPT production by undifferentiated cell cultures is low, differentiated tissues such as root cultures may be a viable alternate source for CPT production. Hairy roots were induced in Ophiorriza rugosa, a source of CPT, using Agrobacterium rhizogenes strain LBA9402. The hairy roots, when cultured in light, showed spontaneous regeneration of shoots. Analysis of CPT levels in the hairy roots and in vitro-grown transformed shoots revealed 0.009% d.w. and 0.012% d.w., respectively.


Subject(s)
Antineoplastic Agents, Phytogenic/biosynthesis , Camptothecin/biosynthesis , Plant Extracts/biosynthesis , Plant Roots/chemistry , Plant Shoots/chemistry , Rubiaceae/chemistry , Agrobacterium , Antineoplastic Agents, Phytogenic/analysis , Antineoplastic Agents, Phytogenic/isolation & purification , Camptothecin/analysis , Camptothecin/isolation & purification , Plant Extracts/analysis , Plant Extracts/isolation & purification , Tissue Culture Techniques
7.
Plant Cell Rep ; 30(10): 1929-38, 2011 Oct.
Article in English | MEDLINE | ID: mdl-21671073

ABSTRACT

The diets of two-thirds of the world's population are deficient in one or more essential elements and one of the approaches to enhance the levels of mineral elements in food crops is by developing plants with ability to accumulate them in edible parts. Besides conventional methods, transgenic technology can be used for enhancing metal acquisition in plants. Copper is an essential element, which is often deficient in human diet. With the objective of developing plants with improved copper acquisition, a high-affinity copper transporter gene (tcu-1) was cloned from fungus Neurospora crassa and introduced into a model plant (Nicotiana tabacum). Integration of the transgene was confirmed by Southern blot hybridization. Transgenic tobacco plants (T(0) and T(1)) expressing tcu-1, when grown in hydroponic medium spiked with different concentrations of copper, showed higher acquisition of copper (up to 3.1 times) compared with control plants. Transgenic plants grown in soil spiked with copper could also take up more copper compared with wild-type plants. Supplementation of other divalent cations such as Cd(2+) and Zn(2+) did not alter uptake of Cu by transgenic plants. The present study has shown that expression of a heterologous copper transporter in tobacco could enhance acquisition of copper.


Subject(s)
Copper/metabolism , Genes, Fungal , Membrane Transport Proteins/metabolism , Nicotiana/metabolism , Cations, Divalent/metabolism , Chlorophyll/analysis , Cloning, Molecular , Gene Expression Regulation, Plant , Hydroponics , Lipid Peroxidation , Membrane Transport Proteins/genetics , Neurospora crassa/genetics , Plants, Genetically Modified/genetics , Plants, Genetically Modified/growth & development , Plants, Genetically Modified/metabolism , Soil , Nicotiana/genetics , Nicotiana/growth & development , Transformation, Genetic , Transgenes
8.
J Hazard Mater ; 192(1): 270-6, 2011 Aug 15.
Article in English | MEDLINE | ID: mdl-21621917

ABSTRACT

Plants can be used for remediation of polyaromatic hydrocarbons, which are known to be a major concern for human health. Metabolism of xenobiotic compounds in plants occurs in three phases and glutathione transferases (GST) mediate phase II of xenobiotic transformation. Plants, although have GSTs, they are not very efficient for degradation of exogenous recalcitrant xenobiotics including polyaromatic hydrocarbons. Hence, heterologous expression of efficient GSTs in plants may improve their remediation and degradation potential of xenobiotics. In the present study, we investigated the potential of transgenic tobacco plants expressing a Trichoderma virens GST for tolerance, remediation and degradation of anthracene-a recalcitrant polyaromatic hydrocarbon. Transgenic plants with fungal GST showed enhanced tolerance to anthracene compared to control plants. Remediation of (14)C uniformly labeled anthracene from solutions and soil by transgenic tobacco plants was higher compared to wild-type plants. Transgenic plants (T(0) and T(1)) degraded anthracene to naphthalene derivatives, while no such degradation was observed in wild-type plants. The present work has shown that in planta expression of a fungal GST in tobacco imparted enhanced tolerance as well as higher remediation potential of anthracene compared to wild-type plants.


Subject(s)
Anthracenes/metabolism , Environmental Restoration and Remediation/methods , Genes, Fungal , Glutathione Transferase/genetics , Nicotiana/physiology , Plants, Genetically Modified/physiology , Trichoderma/genetics , Chromatography, High Pressure Liquid , Gas Chromatography-Mass Spectrometry , Plants, Genetically Modified/enzymology , Plants, Genetically Modified/genetics , Nicotiana/enzymology , Nicotiana/genetics
9.
N Biotechnol ; 28(4): 423-9, 2011 Jul.
Article in English | MEDLINE | ID: mdl-21458603

ABSTRACT

Lindane (γ-hexachlorocyclohexane), a persistent organo-chlorine insecticide widely used in developing countries, has a negative effect as a polluting agent of soil and surface waters. Plants can be used for remediation of organic pollutants and their efficiency can be enhanced by introduction of heterologous genes. Mammalian cytochrome P4502E1 (CYP2E1), an important monooxygenase is involved in the degradation of a wide range of xenobiotics including environmental pollutants/herbicides and pesticides. Here, we report the development of transgenic tobacco plants expressing human CYP2E1 and the efficacy of plants for remediation of lindane. Transgenic tobacco plants with CYP2E1 showed enhanced tolerance to lindane when grown in hydroponic medium and soil compared to control plants. Remediation of (14)C-labeled lindane from hydroponic medium was higher in transgenic plants compared to that of control plants, with the best performing line showing 25% higher removal of lindane from solution than control plants. Similar results were seen in plants grown in soil spiked with lindane. The present study has shown that transgenic plants expressing CYP2E1 gene have potential use for remediation of lindane from contaminated solutions and soil.


Subject(s)
Cytochrome P-450 CYP2E1/metabolism , Hexachlorocyclohexane/pharmacokinetics , Nicotiana/enzymology , Soil Pollutants/pharmacokinetics , Biodegradation, Environmental , Cloning, Molecular , Cytochrome P-450 CYP2E1/genetics , Drug Tolerance/genetics , Gene Expression Regulation, Enzymologic/genetics , Hexachlorocyclohexane/isolation & purification , Humans , Soil Pollutants/isolation & purification , Nicotiana/genetics
10.
PLoS One ; 6(1): e16360, 2011 Jan 21.
Article in English | MEDLINE | ID: mdl-21283689

ABSTRACT

BACKGROUND: Cadmium (Cd) is a major heavy metal pollutant which is highly toxic to plants and animals. Vast agricultural areas worldwide are contaminated with Cd. Plants take up Cd and through the food chain it reaches humans and causes toxicity. It is ideal to develop plants tolerant to Cd, without enhanced accumulation in the edible parts for human consumption. Glutathione transferases (GST) are a family of multifunctional enzymes known to have important roles in combating oxidative stresses induced by various heavy metals including Cd. Some GSTs are also known to function as glutathione peroxidases. Overexpression/heterologous expression of GSTs is expected to result in plants tolerant to heavy metals such as Cd. RESULTS: Here, we report cloning of a glutathione transferase gene from Trichoderma virens, a biocontrol fungus and introducing it into Nicotiana tabacum plants by Agrobacterium-mediated gene transfer. Transgenic nature of the plants was confirmed by Southern blot hybridization and expression by reverse transcription PCR. Transgene (TvGST) showed single gene Mendelian inheritance. When transgenic plants expressing TvGST gene were exposed to different concentrations of Cd, they were found to be more tolerant compared to wild type plants, with transgenic plants showing lower levels of lipid peroxidation. Levels of different antioxidant enzymes such as glutathione transferase, superoxide dismutase, ascorbate peroxidase, guiacol peroxidase and catalase showed enhanced levels in transgenic plants expressing TvGST compared to control plants, when exposed to Cd. Cadmium accumulation in the plant biomass in transgenic plants were similar or lower than wild-type plants. CONCLUSION: The results of the present study suggest that transgenic tobacco plants expressing a Trichoderma virens GST are more tolerant to Cd, without enhancing its accumulation in the plant biomass. It should be possible to extend the present results to crop plants for developing Cd tolerance and in limiting Cd availability in the food chain.


Subject(s)
Cadmium/pharmacology , Glutathione Transferase/pharmacology , Nicotiana/metabolism , Plants, Genetically Modified/metabolism , Trichoderma/enzymology , Animals , Cloning, Molecular , Drug Tolerance/genetics , Food Chain , Food Contamination , Glutathione Transferase/genetics , Humans , Plants, Genetically Modified/enzymology , Plants, Genetically Modified/genetics , Nicotiana/enzymology , Nicotiana/genetics
11.
Physiol Mol Biol Plants ; 17(1): 1-8, 2011 Mar.
Article in English | MEDLINE | ID: mdl-23572990

ABSTRACT

Introduction of foreign genes and development of transgenic plants have become an integral part of crop improvement programmes in the last decade. However, most of the present day plant transformation protocols require long periods for development of transgenic plants and need skilled personnel. Development of alternate, simple and rapid transformation protocols for development of transgenic plants can overcome the constraints of in vitro culture, regeneration and associated problems. Pollen grains, due to their abundance and ease with which they can be handled are ideal targets for introduction of foreign genes into the germ line. However, progress in introduction of transgenes into pollen grains and their subsequent use in fertilization leading to development of transgenic plants are limited. With the recent progress made in understanding of pollen development along with reports of successful pollen-mediated transformation in important crop plants, it should be possible to extend this simple method of transformation to other crop plants. The review deals with development of pollen grains as a target for introduction of genes with special emphasis on recent developments.

12.
Ecotoxicol Environ Saf ; 73(8): 1975-81, 2010 Nov.
Article in English | MEDLINE | ID: mdl-20825988

ABSTRACT

Copper is an essential element for proper functioning of all living organisms including plants, but it can cause toxicity at elevated concentrations. In the present study, two varieties of Brassica juncea L. i.e. Pusa JK and TM 4 grown axenically were compared for Cu tolerance and accumulation ability. For further detailed biochemical studies, var. TM 4 was used because of its fast growth and better Cu accumulation in shoots. Toxic effects of Cu were manifested by a reduction in photosynthetic pigments and an increase in the levels of thiobarbituric acid reactive substances. The activities of antioxidant enzymes such as superoxide dismutase, ascorbate peroxidase, guaiacol peroxidase and catalase showed an increase in a concentration and exposure time dependent manner in roots of B. juncea exposed to copper, indicating that they play an important role in combating copper stress in this species.


Subject(s)
Antioxidants/metabolism , Copper/toxicity , Enzymes/metabolism , Mustard Plant/drug effects , Soil Pollutants/toxicity , Ascorbate Peroxidases , Catalase/metabolism , Lipid Peroxidation/drug effects , Mustard Plant/growth & development , Mustard Plant/metabolism , Oxidative Stress/drug effects , Peroxidase/metabolism , Peroxidases/metabolism , Photosynthesis , Pigments, Biological/metabolism , Plant Roots/drug effects , Plant Roots/growth & development , Plant Roots/metabolism , Plant Shoots/drug effects , Plant Shoots/growth & development , Plant Shoots/metabolism , Soil Pollutants/chemistry , Superoxide Dismutase/metabolism , Thiobarbituric Acid Reactive Substances/metabolism , Time Factors
13.
Plant Cell Environ ; 33(10): 1697-707, 2010 Oct.
Article in English | MEDLINE | ID: mdl-20492552

ABSTRACT

Zinc (Zn) is an essential micronutrient required for growth and development of all organisms. Deficiency of Zn in humans is widespread, affecting 25% of world population and efforts are underway to develop crop plants with high levels of Zn in their edible parts. When strategies for enhancing Zn in crop plants are designed, it is essential to exclude cadmium (Cd), a toxic analogue of Zn. In the present work, a high affinity and high specificity zinc transporter gene (tzn1) from Neurospora crassa was cloned and introduced into Nicotiana tabacum with the objective of enhancing the potential of plants for zinc acquisition. When grown in hydroponic medium spiked with (65) Zn, transgenic plants showed enhanced accumulation of Zn (up to 11 times) compared to control plants, which was confirmed further by environmental scanning electron microscopy coupled with Energy Dispersive X-ray analysis. More importantly, no significant difference in uptake of Cd(2+), Fe(2+), Ni(2+), Cu(2+), Mn(2+) and Pb(2+) between the transgenic and control plants was observed. The present studies have shown that Neurospora crassa tzn1 is a potential candidate gene for developing transgenic plants for improving Zn uptake, without co-transport of Cd and may have implications in Zn phytofortification and phytoremediation.


Subject(s)
Carrier Proteins/genetics , Carrier Proteins/metabolism , Fungal Proteins/genetics , Neurospora crassa/genetics , Nicotiana/genetics , Nicotiana/metabolism , Zinc/metabolism , Cadmium/metabolism , Cations, Divalent/metabolism , Chlorophyll/metabolism , Cloning, Molecular , Gene Expression Regulation, Plant , Lipid Peroxidation , Microscopy, Electron, Scanning , Plants, Genetically Modified , Spectrometry, X-Ray Emission , Nicotiana/growth & development
14.
Physiol Mol Biol Plants ; 16(1): 39-51, 2010 Jan.
Article in English | MEDLINE | ID: mdl-23572953

ABSTRACT

Development of transgenic Nicotiana tabacum and Lycopersicon esculentum expressing an endochitinase (ech42) gene from biocontrol fungus Trichoderma virens using Agrobacterium-mediated genetic transformation is reported in this paper. Integration of transgene in the genome of transgenic plants was demonstrated using polymerase chain reaction and Southern-blot hybridization, while expression was ascertained by reverse transcription polymerase chain reaction. Histochemical analysis confirmed the expression of GUS enzyme in transformed shoots. Levels of endochitinase enzyme in transgenic plants were found to be up to 10 fold higher compared to control plants. Endochitinase enzyme of 42 kDa was also visualized on SDS-PAGE gel using fluorimetric zymogram in transgenic plants. Endochitinase activity was found to be higher in leaf and stem than the root tissue in transgenic tomato plants. Transgenic lines of both plants showed enhanced resistance to fungal pathogens and a strong negative correlation was found between expression level of endochitinase enzyme and size of disease lesions. Inheritance of transgene, expression and resistance to fungal pathogens of T1 transgenic tobacco lines was also analysed. The results of the present studies show that ech42 is a promising candidate gene for developing fungal disease resistance in tomato plants.

15.
Physiol Mol Biol Plants ; 16(3): 273-84, 2010 Jul.
Article in English | MEDLINE | ID: mdl-23572977

ABSTRACT

Agrobacterium-mediated transformation in chickpea was developed using strain LBA4404 carrying nptII, uidA and cryIAc genes and transformants selected on Murashige and Skoog's basal medium supplemented with benzyladenine, kinetin and kanamycin. Integration of transgenes was demonstrated using polymerase chain reaction and Southern blot hybridization of T0 plants. The expression of CryIAc delta endotoxin and GUS enzyme was shown by enzyme linked immunosorbent assay and histochemical assay respectively. The transgenic plants (T0) showed more tolerance to infection by Helicoverpa armigera compared to control plants. Various factors such as explant source, cultivar type, different preculture treatment period of explants, co-cultivation period, acetosyringone supplementation, Agrobacterium harboring different plasmids, vacuum infiltration and sonication treatment were tested to study the influence on transformation frequency. The results indicated that use of epicotyl as explant, cultivar ICCC37, Agrobacterium harboring plasmid pHS102 as vector, preculture of explant for 48 h, co-cultivation period of 2 days at 25°C and vacuum infiltration for 15 min produced the best transformation results. Sonication treatment of explants with Agrobacteria for 80 s was found to increase the frequency of transformation.

16.
J Hazard Mater ; 162(2-3): 743-5, 2009 Mar 15.
Article in English | MEDLINE | ID: mdl-18599208

ABSTRACT

Potential of Chromolaena odorata plants for remediation of (137)Cs from solutions and low level nuclear waste was evaluated. When plants were exposed to solutions spiked with three different levels of (137)Cs, namely 1 x 10(3) kBqL(-1), 5 x 10(3) kBqL(-1) and 10 x 10(3) kBqL(-1), 89%, 81% and 51% of (137)Cs was found to be remediated in 15 d, respectively. At the lowest Cs activity (1 x 10(3) kBqL(-1)), accumulation of Cs was found to be higher in roots compared to shoots, while at higher Cs activities (5 x 10(3) kBqL(-1) and 10 x 10(3) kBqL(-1)), Cs accumulation was more in shoots than roots. When plants were incubated in low level nuclear waste, 79% of the activity was removed by plants at the end of 15 d. The present study suggests that C. odorata could be used as a potential candidate plant for phytoremediation of (137)Cs.


Subject(s)
Cesium Radioisotopes/metabolism , Chromolaena/metabolism , Environmental Restoration and Remediation/methods , Radioactive Pollutants/metabolism , Solutions
17.
Ecotoxicol Environ Saf ; 71(3): 671-6, 2008 Nov.
Article in English | MEDLINE | ID: mdl-18082265

ABSTRACT

Aseptically grown Vetiveria zizanoides were evaluated for their potential for phytoremediation of phenol from Murashige and Skoog's liquid medium. Phenol was found to be completely removed from incubation medium at the end of 4 days by V. zizanoides plantlets, when medium was supplemented with 50 and 100 mg L(-1) phenol, while with 200, 500, and 1000 mg L(-1) of phenol, 89%, 76% and 70%, respectively, were removed. Phenol removal was found to be associated with inherent production of peroxidase and hydrogen peroxide. Coupled with H(2)O(2) formation, the levels of antioxidant enzymes like superoxide dismutase and peroxidase showed an enhancement when plants were exposed to phenol, whereas catalase levels initially showed a decline due to the utilization of H(2)O(2) by peroxidase for phenol oxidation. However, when peroxidase levels declined, there was an enhancement in catalase levels to minimize the presence of H(2)O(2) in the medium. Having confirmed that the removal of phenol was by V. zizanoides plantlets, in the next phase, micropropagated plantlets and well-developed plants grown in hydroponics were used under in vivo conditions to study the effect of phenol (200 mg L(-1)) on plant growth and reuse. Although plant growth was reduced in presence of phenol, the results of the reuse study indicated the possibility of plants getting adapted to phenol without any decline in potential for phenol remediation.


Subject(s)
Chrysopogon/metabolism , Phenol/metabolism , Water Pollutants, Chemical/metabolism , Antioxidants/metabolism , Biodegradation, Environmental , Catalase/metabolism , Chrysopogon/drug effects , Glutathione Peroxidase , Hydrogen Peroxide/metabolism , Hydroponics , Oxidation-Reduction , Peroxidase/metabolism , Phenol/analysis , Phenol/toxicity , Superoxide Dismutase/metabolism , Water Pollutants, Chemical/analysis , Water Pollutants, Chemical/toxicity
18.
Biotechnol Adv ; 26(2): 162-8, 2008.
Article in English | MEDLINE | ID: mdl-18055156

ABSTRACT

It is three decades since the first transgenic pulse crop has been developed. Todate, genetic transformation has been reported in all the major pulse crops like Vigna species, Cicer arietinum, Cajanus cajan, Phaseolus spp, Lupinus spp, Vicia spp and Pisum sativum, but transgenic pulse crops have not yet been commercially released. Despite the crucial role played by pulse crops in tropical agriculture, transgenic pulse crops have not moved out from laboratories to large farm lands compared to their counterparts - 'cereals' and the closely related leguminous oil crop - 'soybean'. The reason for lack of commercialization of transgenic pulse crops can be attributed to the difficulty in developing transgenics with reproducibility, which in turn is due to lack of competent totipotent cells for transformation, long periods required for developing transgenics and lack of coordinated research efforts by the scientific community and long term funding. With optimization of various factors which influence genetic transformation of pulse crops, it will be possible to develop transgenic plants in this important group of crop species with more precision and reproducibility. A translation of knowledge from information available in genomics and functional genomics in model legumes like Medicago truncatula and Lotus japonicus relating to factors which contribute to enhancing crop yield and ameliorate the negative consequences of biotic and abiotic stress factors may provide novel insights for genetic manipulation to improve the productivity of pulse crops.


Subject(s)
Agriculture/methods , Agriculture/trends , Fabaceae/genetics , Food, Genetically Modified , Gene Transfer Techniques/trends , Genetic Enhancement/methods , Plants, Genetically Modified/genetics , Forecasting
19.
Ecotoxicol Environ Saf ; 69(2): 306-11, 2008 Feb.
Article in English | MEDLINE | ID: mdl-17257679

ABSTRACT

Vetiver grass (Vetiveria zizanoides) L. Nash plantlets when tested for their potential to remove (90)Sr and (137)Cs (5 x 10(3) k Bq l(-1)) from solutions spiked with individual radionuclide showed that 94% of (90)Sr and 61% of (137)Cs could be removed from solutions after 168 h. When both (90)Sr and (137)Cs were supplemented together to the solution, 91% of (90)Sr and 59% of (137)Cs were removed at the end of 168 h. In case of (137)Cs, accumulation occurred more in roots than shoots, while (90)Sr accumulated more in shoots than roots. When experiments were performed to study the effect of analogous elements, K(+) ions reduced the uptake of (137)Cs, while (90)Sr accumulation was found to decrease in the presence of Ca(2+) ions. Plants of V. zizanoides could also effectively remove radioactive elements from low-level nuclear waste and the level of radioactivity was reduced below detection limit at the end of 15 days of exposure. The results of the present study indicate that V. zizanoides may be a potential candidate plant for phytoremediation of (90)Sr and (137)Cs.


Subject(s)
Cesium Radioisotopes/metabolism , Chrysopogon/metabolism , Radioactive Waste , Strontium Radioisotopes/metabolism , Water Pollutants, Radioactive/metabolism , Biodegradation, Environmental , Plant Roots/metabolism , Plant Shoots/metabolism
20.
Biotechnol Adv ; 25(5): 442-51, 2007.
Article in English | MEDLINE | ID: mdl-17553651

ABSTRACT

Phytoremediation-the use of plants for cleaning up of xenobiotic compounds-has received much attention in the last few years and development of transgenic plants tailored for remediation will further enhance their potential. Although plants have the inherent ability to detoxify some xenobiotic pollutants, they generally lack the catabolic pathway for complete degradation/mineralization of these compounds compared to microorganisms. Hence, transfer of genes involved in xenobiotic degradation from microbes/other eukaryotes to plants will further enhance their potential for remediation of these dangerous groups of compounds. Transgenic plants with enhanced potential for detoxification of xenobiotics such as trichloro ethylene, pentachlorophenol, trinitro toluene, glycerol trinitrate, atrazine, ethylene dibromide, metolachlor and hexahydro-1,3,5-trinitro-1,3,5-triazine are a few successful examples of utilization of transgenic technology. As more genes involved in xenobiotic metabolism in microorganisms/eukaryotes are discovered, it will lead to development of novel transgenic plants with improved potential for degradation of recalcitrant contaminants. Selection of suitable candidate plants, field testing and risk assessment are important considerations to be taken into account while developing transgenic plants for phytoremediation of this group of pollutants. Taking advantage of the advances in biotechnology and 'omic' technologies, development of novel transgenic plants for efficient phytoremediation of xenobiotic pollutants, field testing and commercialization will soon become a reality.


Subject(s)
Biotechnology/methods , Environmental Restoration and Remediation/methods , Plants, Genetically Modified , Soil Pollutants/chemistry , Xenobiotics/chemistry , Biodegradation, Environmental , Environmental Pollution , Genetic Engineering , Hazardous Substances , Models, Biological , Mutagenesis , Plants/metabolism , Risk Assessment , Water Pollutants, Chemical
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