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1.
Tissue Cell ; 79: 101968, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36356560

RESUMO

INTRODUCTION: Adipose-derived stem cells (ASCs) have been proven to have tumoricidal effects against hepatic cancer cell lines. However, it appears that exposure to oxidative microenvironment compromises the potential outcome of ASCs in real hepatoma. Herein, we aimed to examine the tumoricidal effects of ASCs under oxidative conditions and to investigate the impact of curcumin priming on ASCs' therapeutic potential. METHODS: We used human hepatoma (HepG2) cells in a coculture system with unprimed or curcumin-primed ASCs (Cur-ASCs) under H2O2-induced oxidative conditions. To investigate HepG2 proliferation and death, MTT (3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide) and annexin V staining assays were performed. To determine the HepG2 migration and invasion potential, the scratch healing and the transwell invasion assays were performed. To evaluate the expression of apoptosis-protein markers, Western blotting was performed. RESULTS: Cur-ASCs suppressed HepG2 proliferation, migration, and invasion as well as prompted apoptosis more significantly compared to unprimed ASCs under oxidative conditions. Expressional studies also revealed an obvious decline in the BCL-2/BAX ratio in HepG2 cocultured with Cur-ASCs. In addition, we noticed a marked elevation of apoptosis and senescence in unprimed ASCs compared to Cur-ASCs after coculture experiments, which demonstrated that curcumin priming preserved the survival and growth potential of ASCs; hence, Cur-ASCs performed better tumoricidal functions under oxidative conditions. CONCLUSION: Our findings suggest that ASCs have the intrinsic ability to induce cell death in HepG2 cells; however, their functions can be compromised under oxidative conditions. We believe that curcumin priming is an effective approach for improving the therapeutic effectiveness of ASCs in the cancerous microenvironment.


Assuntos
Carcinoma Hepatocelular , Curcumina , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/tratamento farmacológico , Células Hep G2 , Curcumina/farmacologia , Peróxido de Hidrogênio , Neoplasias Hepáticas/tratamento farmacológico , Células-Tronco , Estresse Oxidativo , Microambiente Tumoral
2.
Genes (Basel) ; 13(6)2022 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-35741708

RESUMO

Rapidly mutating Y-chromosomal short tandem repeats (RM Y STRs) with mutation rates ≥ 10-2 per locus per generation are valuable for differentiating amongst male paternal relatives where standard Y STRs with mutation rates of ≤10-3 per locus per generation may not. Although the 13 RM Y STRs commonly found in commercial assays provide higher levels of paternal lineage differentiation than conventional Y STRs, there are many male paternal relatives that still cannot be differentiated. This can be improved by increasing the number of Y STRs or choosing those with high mutation rates. We present a RM Y STR multiplex comprising 19 loci with high mutation rates and its developmental validation (repeatability, sensitivity and male specificity). The multiplex was found to be robust, reproducible, specific and sensitive enough to generate DNA profiles from samples with inhibitors. It was also able to detect all contributor alleles of mixtures in ratios up to 9:1. We provide preliminary evidence for the ability of the multiplex to discriminate between male paternal relatives by analyzing large numbers of male relative pairs (536) separated by one to seven meioses. A total of 96 mutations were observed in 162 meioses of father-son pairs, and other closely related male pairs were able to be differentiated after 1, 2, 3, 4, 5, 6 and 7 meiosis in 44%, 69%, 68%, 85%, 0%, 100% and 100% of cases, respectively. The multiplex offers a noticeable enhancement in the ability to differentiate paternally related males compared with the 13 RM Y STR set. We envision the future application of our 19 RM Yplex in criminal cases for the exclusion of male relatives possessing matching standard Y STR profiles and in familial searching with unknown suspects. It represents a step towards the complete individualization of closely related males.


Assuntos
Cromossomos Humanos Y , Neuroblastoma , Cromossomos Humanos Y/genética , Pai , Haplótipos , Humanos , Masculino , Repetições de Microssatélites/genética , Taxa de Mutação , Neuroblastoma/genética
3.
Sci Rep ; 12(1): 2518, 2022 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-35169256

RESUMO

Stacking multiple genes into cotton crop to cop up multiple biotic stresses such as insects and weeds is a promising tool to save crop from losses. Transgenic cotton variety, VH-289, with double Bt and cp4EPSPS genes under the control of 35S promoter was used for the expression analyses and biosafety studies. The transgenic cotton plants were screened through PCR amplification of fragments, 1.7 kb for Cry1Ac, 582 bp for Cry2A and 250 bp for cp4EPSPS; which confirmed the presence of all genes transformed in transgenic cotton. The Cry1Ac + Cry2A and cp4EPSPS proteins were quantified through ELISA in transgenic cotton plants. The Glyphosate assay performed by spraying 1900 mL per acre of glyphosate Roundup further confirmed complete survival of transgenic cotton plants as compared to the non-transgenic cotton plants and all weeds. Similarly, insect infestation data determined that almost 99% insect mortality was observed in controlled field grown transgenic cotton plants as compared to the non-transgenic control plants. Evaluation of effect of temperature and soil nutrients availability on transgene expression in cotton plants was done at two different cotton growing regions, Multan and Lahore, Pakistan and results suggested that despite of higher temperature in Multan field, an increased level of Cry and cp4EPSPS proteins was recorded due to higher soil organic matter availability compared to Lahore field. Before commercialization of any transgenic variety its biosafety study is mandatory so, a 90 days biosafety study of the transgenic cotton plants with 40% transgenic cottonseeds in standard diet showed no harmful effect on wister rat model when studied for liver function, renal function and serum electrolyte.


Assuntos
Glicina/análogos & derivados , Gossypium/efeitos dos fármacos , Gossypium/genética , Resistência a Herbicidas/genética , Herbicidas/farmacologia , Lepidópteros , Plantas Daninhas/efeitos dos fármacos , Animais , Dieta/métodos , Endotoxinas/genética , Endotoxinas/metabolismo , Glicina/farmacologia , Gossypium/metabolismo , Proteínas Hemolisinas/genética , Proteínas Hemolisinas/metabolismo , Larva , Testes de Função Hepática , Masculino , Modelos Animais , Paquistão , Folhas de Planta/genética , Folhas de Planta/metabolismo , Plantas Geneticamente Modificadas/efeitos dos fármacos , Plantas Geneticamente Modificadas/metabolismo , Ratos , Ratos Wistar , Medição de Risco , Sementes/genética , Sementes/metabolismo , Transgenes , Glifosato
4.
J Biomol Struct Dyn ; 40(17): 7829-7851, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-33764266

RESUMO

Berberis lyceum and Fumaria indica are two Pakistani indigenous herbal medicines used to treat liver infections, including hepatitis C virus (HCV). This study aimed to evaluate the cytotoxicity, and antioxidant activity of these plant extracts and computationally screen their selected phytoconstituents as HCV NS5A inhibitors. The viability of HepG2 cells was assessed 24 h and 48 h post-treatment using colorimetric and dye exclusion methods. Antioxidant properties were examined by the 2,2-diphenyl-1-picrylhydrazyl (DPPH), reducing power, and total antioxidant capacity assays. Seventeen known phytochemicals identified from each plant were docked into the active binding site of HCV NS5A protein. The top hit ligands were analyzed for their druglikeness properties and the indices of absorption, distribution, metabolism, elimination, and toxicity (ADMET). The results showed that both plant extracts were non-toxic (CC50 > 200 µg/ml). The IC50 values of DPPH-radical scavenging activity were 51.02 ± 0.94 and 62.91 ± 1.85 µg/ml for B. lyceum and F. indica, respectively. They also exhibited reducing power and total antioxidant capacity.The phytochemicals were identified as potent HCV NS5A inhibitors with good druglikeness and ADMET properties. Six of the docked phytochemicals exhibited higher binding scores (-17.9 to -19.2 kcal/mol) with HCV NS5A protein than the standard drug, daclatasvir (-17.2 kcal/mol). Molecular dynamics (MD) simulation confirmed the stability of two compounds, berbamine and paprafumine at 100 ns with active site of HCV NS5A protein. The identified compounds through molecular docking and MD simulation could have potential as HCV NS5A inhibitor after further validation.


Assuntos
Berberis , Fumaria , Hepatite C , Antioxidantes/farmacologia , Antivirais/química , Berberis/metabolismo , Hepacivirus/metabolismo , Simulação de Acoplamento Molecular , Compostos Fitoquímicos/metabolismo , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/metabolismo , Extratos Vegetais/farmacologia , Proteínas não Estruturais Virais/química
5.
Sci Rep ; 11(1): 12428, 2021 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-34127751

RESUMO

Sugarcane (Saccharum officinarum L.) is a cash crop grown commercially for its higher amounts of sucrose, stored within the mature internodes of the stem. Numerous studies have been done for the resistance development against biotic and abiotic stresses to save the sucrose yields. Quality and yield of sugarcane production is always threatened by the damages of cane borers and weeds. In current study two problems were better addressed through the genetic modification of sugarcane for provision of resistance against insects and weedicide via the expression of two modified cane borer resistant CEMB-Cry1Ac (1.8 kb), CEMB-Cry2A (1.9 kb) and one glyphosate tolerant CEMB-GTGene (1.4 kb) genes, driven by maize Ubiquitin Promoter and nos terminator. Insect Bio-toxicity assays were carried out for the assessment of Cry proteins through mortality percent of shoot borer Chilo infuscatellus at 2nd instar larvae stage. During V0, V1 and V2 generations young leaves from the transgenic sugarcane plants were collected at plant age of 20, 40, 60, 80 days and fed to the Chilo infuscatellus larvae. Up to 100% mortality of Chilo infuscatellus from 80 days old transgenic plants of V2 generation indicated that these transgenic plants were highly resistant against shoot borer and the gene expression level is sufficient to provide complete resistance against target pests. Glyphosate spray assay was carried out for complete removal of weeds. In V1-generation, 70-76% transgenic sugarcane plants were found tolerant against glyphosate spray (3000 mL/ha) under field conditions. While in V2-generation, the replicates of five selected lines 4L/2, 5L/5, 6L/5, L8/4, and L9/6 were found 100% tolerant against 3000 mL/ha glyphosate spray. It is evident from current study that CEMB-GTGene, CEMB-Cry1Ac and CEMB-Cry2A genes expression in sugarcane variety CPF-246 showed an efficient resistance against cane borers (Chilo infuscatellus) and was also highly tolerant against glyphosate spray. The selected transgenic sugarcane lines showed sustainable resistance against cane borer and glyphosate spray can be further exploited at farmer's field level after fulfilling the biosafety requirements to boost the sugarcane production in the country.


Assuntos
Produtos Agrícolas/genética , Resistência à Doença/genética , Controle de Pragas/métodos , Plantas Geneticamente Modificadas/genética , Saccharum/genética , Animais , Produtos Agrícolas/efeitos dos fármacos , Produtos Agrícolas/parasitologia , Glicina/análogos & derivados , Glicina/farmacologia , Resistência a Herbicidas/genética , Larva , Mariposas , Proteínas de Plantas/genética , Plantas Daninhas , Plantas Geneticamente Modificadas/efeitos dos fármacos , Plantas Geneticamente Modificadas/parasitologia , Saccharum/efeitos dos fármacos , Saccharum/parasitologia , Glifosato
6.
J Ethnopharmacol ; 272: 113938, 2021 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-33610708

RESUMO

ETHNOBOTANICAL RELEVANCE: Tectona grandis L.f (or syn: Jatus grandis (L.f.) Kuntze Revis), from family Lamiaceae, also known as Teak, is widely recognized in ayurvedic system of medicine and confer curative potential against inflammation, liver disorders, biliousness, diabetes, bronchitis, leprosy and dysentery. Its leaves are rich source of edible food colorant and reported nontoxic for liver and various organs. AIM OF STUDY: Hepatic injury progression to liver cirrhosis and cancer is a serious health issue across the world. Currently, anti-fibrotic therapeutic options are limited and expensive with no FDA approved direct anti-hepato-fibrotic drug validated in clinic. Thus, the aim of this study was to understand ameliorative effect of Tectona grandis L.f, leaves in early liver fibrosis. METHOD AND RESULTS: C57BL/6 mice suffering from CCl4 induced liver injury, were orally administered at three different doses (50, 100 & 200 mg/kg) of Tectona grandis L.f, leaf extract, thrice a week, up to 4 and 8 weeks. Anti-fibrotic effect was evaluated through animal body/liver weight measurements, serological tests (AST, ALT, GSH, MDA and LDH assays), tissue hydroxyproline content, and histochemical analysis (H&E, Masson trichrome, Sirius red and αSMA localization). Moreover, transcriptional and post-transcriptional expression of fibrosis associated biomarkers and TGF-ß/Smad cascade were analyzed. It was observed that 100 mg/kg dose optimally downregulated TGF-ß1/Smad2 with upregulation of Smad7 and regulated αSMA, Col 1, PDGF, TIMP1 and MMP3 expression, post 8 weeks of treatment. In addition, MMP3/TIMP1 ratio was upregulated to 0.7, 2.5 and 1.7 fold at 50 mg/kg, 100 mg/kg & 200 mg/kg treatments respectively, in comparison to untreated liver fibrosis models. The extract contains gallic acid, caffeic acid, sinapinic acid and myricetin when analyzed through high performance liquid chromatography. CONCLUSION: Tectona grandis L.f, leaves have potential to ameliorate liver fibrosis induced by CCl4 in mice via modulation of TGF-ß1/Smad pathway and upregulated MMP3/TIMP1 ratio.


Assuntos
Lamiaceae/química , Cirrose Hepática/prevenção & controle , Metaloproteinase 3 da Matriz/metabolismo , Substâncias Protetoras/farmacologia , Substâncias Protetoras/intoxicação , Transdução de Sinais/efeitos dos fármacos , Proteína Smad2/metabolismo , Inibidor Tecidual de Metaloproteinase-1/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Animais , Tetracloreto de Carbono/toxicidade , Sobrevivência Celular/efeitos dos fármacos , Chlorocebus aethiops , Colágeno/metabolismo , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Células Hep G2 , Células Estreladas do Fígado/efeitos dos fármacos , Humanos , Cirrose Hepática/induzido quimicamente , Cirrose Hepática/metabolismo , Cirrose Hepática/patologia , Metaloproteinase 3 da Matriz/genética , Camundongos Endogâmicos C57BL , Extratos Vegetais/administração & dosagem , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Folhas de Planta/química , Substâncias Protetoras/química , Proteína Smad2/genética , Inibidor Tecidual de Metaloproteinase-1/genética , Transaminases/sangue , Fator de Crescimento Transformador beta/genética , Células Vero
7.
Mol Biotechnol ; 62(8): 370-379, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32347477

RESUMO

Pullulanase type I (PulA) is a debranching enzyme that specifically cleaves α-1,6-glycosidic linkages in pullulan. Pullulan has not only diverse applications in food industry but also has immune-stimulatory effects on B and T cells, and found to enhance the production of various anti-inflammatory cytokines in human. Moreover, pullulan has been suggested as a possible anti-cancer drug delivery agent without adjuvant due to its unique structure. The process of pullulan degradation is unresolved due to imprecise pullulanase structural characteristics. Therefore, the present study aimed to understand the structural and functional characteristics of pullulanase enzyme from Geobacillus thermopakistaniensis MAS1 strain using various computational approaches. The physio-chemical topographies and secondary structure of GT_PulA were explored using ProPram, InterPro and SMART. Various tools like I-TASSER, ModRefiner, RAMPAGE, PROCHECK and MOE 2009.10 were used to construct and verify the 3D structural model. The structural elucidation confirmed the significant domains, i.e., CBM48, CBM2, and TIM barrel having catalytically active residues, and conserved region YNGWDP. CBM2 domain along with TIM barrel has a capacity to bind different ligands and proved favorable for multiple substrate catalyses. These structural properties can have a potential effect on enhancing enzymatic activity of GT_PulA enzyme.


Assuntos
Proteínas de Bactérias , Geobacillus , Glicosídeo Hidrolases , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Estabilidade Enzimática , Geobacillus/enzimologia , Geobacillus/genética , Glicosídeo Hidrolases/química , Glicosídeo Hidrolases/genética , Glicosídeo Hidrolases/metabolismo , Simulação de Acoplamento Molecular , Polissacarídeos/química , Polissacarídeos/metabolismo , Proto-Oncogene Mas
8.
MethodsX ; 6: 259-264, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30792967

RESUMO

Extraction of high-quality DNA from Gossypium (Cotton) species is notoriously difficult due to high contents of polysaccharides, quinones and polyphenols other secondary metabolites. Here, we describe a simple, rapid and modified procedure for high-quality DNA extraction from cotton, which is amenable for downstream analyses. In contrast to other CTAB methods, the described procedure is rapid, omits the use of liquid nitrogen, phenol, CsCl gradient ultracentrifugation, uses inexpensive and less hazardous reagents, and requires only ordinary laboratory equipment. The procedure employed the high concentration of NaCl and use of PVP-10 to rid the problems associated with polysaccharides and polyphenols, respectively. The average yield was approximately 10-15 µg of good quality DNA from 100 mg of tissue weight, which is adequate for projects, like genetic mapping or marker-assisted plant breeding. This protocol can be performed in as little as 3 h and may be adapted to high-throughput DNA isolation. •Buffers A and B were redesigned from Paterson et al. (1993) and Porebski et al. (1997), respectively.•Ribonuclease A was added before chloroform extraction.•A simple, rapid and inexpensive DNA extraction method is described.

9.
Biol. Res ; 48: 1-11, 2015. ilus, tab
Artigo em Inglês | LILACS | ID: biblio-950778

RESUMO

BACKGROUND: Insects have developed resistance against Bt-transgenic plants. A multi-barrier defense system to weaken their resistance development is now necessary. One such approach is to use fusion protein genes to increase resistance in plants by introducing more Bt genes in combination. The locating the target protein at the point of insect attack will be more effective. It will not mean that the non-green parts of the plants are free of toxic proteins, but it will inflict more damage on the insects because they are at maximum activity in the green parts of plants. RESULTS: Successful cloning was achieved by the amplification of Cry2A, Cry1Ac, and a transit peptide. The appropriate polymerase chain reaction amplification and digested products confirmed that Cry1Ac and Cry2A were successfully cloned in the correct orientation. The appearance of a blue color in sections of infiltrated leaves after 72 hours confirmed the successful expression of the construct in the plant expression system. The overall transformation efficiency was calculated to be 0.7%. The amplification of Cry1Ac-Cry2A and Tp2 showed the successful integration of target genes into the genome of cotton plants. A maximum of 0.673 µg/g tissue of Cry1Ac and 0.568 µg/g tissue of Cry2A was observed in transgenic plants. We obtained 100% mortality in the target insect after 72 hours of feeding the 2nd instar larvae with transgenic plants. The appearance of a yellow color in transgenic cross sections, while absent in the control, through phase contrast microscopy indicated chloroplast localization of the target protein. CONCLUSION: Locating the target protein at the point of insect attack increases insect mortality when compared with that of other transgenic plants. The results of this study will also be of great value from a biosafety point of view.


Assuntos
Animais , Proteínas de Bactérias/genética , Proteínas Recombinantes de Fusão , Cloroplastos/genética , Controle de Insetos/métodos , Gossypium/genética , Endotoxinas/genética , Proteínas Hemolisinas/genética , Lepidópteros , Bacillus thuringiensis , Proteínas de Bactérias/análise , Resistência a Inseticidas/genética , Imuno-Histoquímica , Expressão Gênica/genética , Cloroplastos/metabolismo , Reação em Cadeia da Polimerase , Microscopia de Contraste de Fase , Plantas Geneticamente Modificadas , Clonagem Molecular , Primers do DNA , Folhas de Planta/genética , Transgenes/fisiologia , Endotoxinas/análise , Fusão Gênica , Proteínas Hemolisinas/análise , Inseticidas , Larva
10.
Viruses ; 6(1): 223-42, 2014 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-24424501

RESUMO

The C1 promoter expressing the AC1 gene, and V1 promoter expressing the AV1 gene are located in opposite orientations in the large intergenic region of the Cotton leaf curl Burewala virus (CLCuBuV) genome. Agro-infiltration was used to transiently express putative promoter constructs in Nicotiana tabacum and Gossypium hirsutum leaves, which was monitored by a GUS reporter gene, and revealed that the bidirectional promoter of CLCuBuV transcriptionally regulates both the AC1 and AV1 genes. The CLCuBuV C1 gene promoter showed a strong, consistent transient expression of the reporter gene (GUS) in N. tabacum and G. hirsutum leaves and exhibited GUS activity two- to three-fold higher than the CaMV 35S promoter. The CLCuBuV bidirectional gene promoter is a nearly constitutive promoter that contains basic conserved elements. Many cis-regulatory elements (CREs) were also analyzed within the bidirectional plant promoters of CLCuBuV and closely related geminiviruses, which may be helpful in understanding the transcriptional regulation of both the virus and host plant.


Assuntos
Begomovirus/genética , Expressão Gênica , Gossypium/genética , Biologia Molecular/métodos , Nicotiana/genética , Regiões Promotoras Genéticas , Agrobacterium/genética , Perfilação da Expressão Gênica , Genes Reporter , Gossypium/virologia , Folhas de Planta/genética , Plantas Geneticamente Modificadas , Nicotiana/virologia , Transformação Genética , beta-Glucosidase/biossíntese , beta-Glucosidase/genética
11.
Electron. j. biotechnol ; 16(6): 13-13, Nov. 2013. ilus, tab
Artigo em Inglês | LILACS | ID: lil-696554

RESUMO

Background: Transgenic plants inhabiting single Bt gene are prone to develop insect resistance and this resistance has been reported in case of some important yield-devastating insect larvae of commercial crops, such as cotton and rice. Therefore, it has become essential to adapt new strategies to overcome the problem of insect resistance and these new strategies should be sophisticated enough to target such resistant larvae in broad spectrum. Among these, plants may be transformed with Bt gene tagged with some fusion-protein gene that possesses lectin-binding capability to boost the binding sites for crystal protein gene within insect mid-gut in order to overcome any chances of insect tolerance against Bt toxin. Enhanced chloroplast-targeted Bt gene expression can also help in the reduction of insect resistance. Results: In the present investigation, a combined effect of both these strategies was successfully used in cotton (G. hirsutum). For this purpose, plant expression vector pKian-1 was created, after a series of cloning steps, carrying Cry1Ac gene ligated with chloroplast transit peptide towards N-terminal and Ricin B-Chain towards C-terminal, generating TP-Cry1Ac-RB construct. Conclusions: Efficacy of pKian-1 plasmid vector was confirmed by in-planta Agrobacterium-mediated leaf GUS assay in tobacco. Cotton (G. hirsutum) local variety MNH-786 was transformed with pKian-1 and the stable integration of TP-Cry1Ac-RB construct in putative transgenic plants was confirmed by PCR; while fusion-protein expression in cytosol as well as chloroplast was substantiated by Western blot analysis. Whereas, confocal microscopy of leaf-sections of transgenic plants exposed that hybrid-Bt protein was expressing inside chloroplasts.


Assuntos
Cloroplastos/genética , Cloroplastos/metabolismo , Plantas Geneticamente Modificadas , Proteínas de Cloroplastos/isolamento & purificação , Ricina/análise , Sinais Direcionadores de Proteínas , Western Blotting , Clonagem Molecular , Microscopia Confocal , Agrobacterium , Proteínas de Cloroplastos/genética , Insetos
12.
J Biotechnol ; 166(3): 88-96, 2013 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-23643479

RESUMO

Plants transformed with single Bt gene are liable to develop insect resistance and this has already been reported in a number of studies carried out around the world where Bt cotton was cultivated on commercial scale. Later, it was envisaged to transform plants with more than one Bt genes in order to combat with resistant larvae. This approach seems valid as various Bt genes possess different binding domains which could delay the likely hazards of insect resistance against a particular Bt toxin. But it is difficult under field conditions to develop homozygous plants expressing all Bt genes equally after many generations without undergoing recombination effects. A number of researches claiming to transform plants from three to seven transgenes in a single plant were reported during the last decade but none has yet applied for patent of homozygous transgenic lines. A better strategy might be to use hybrid-Bt gene(s) modified for improved lectin-binding domains to boost Bt receptor sites in insect midgut. These recombinant-Bt gene(s) would express different lectin domains in a single polypeptide and it is relatively easy to develop homozygous transgenic lines under field conditions. Enhanced chloroplast-localized expression of hybrid-Bt gene would leave no room for insects to develop resistance. We devised and successfully applied this strategy in cotton (Gossypium hirsutum) and data up to T3 generation showed that our transgenic cotton plants were displaying enhanced chloroplast-targeted Cry1Ac-RB expression. Laboratory and field bioassays gave promising results against American bollworm (Heliothis armigera), pink bollworm (Pictinophora scutigera) and fall armyworm (Spodoptera frugiperda) that otherwise, were reported to have evolved resistance against Cry1Ac toxin. Elevated levels of hybrid-Bt toxin were confirmed by ELISA of chloroplast-enriched protein samples extracted from leaves of transgenic cotton lines. While, localization of recombinant Cry1Ac-RB protein in chloroplast was established through confocal laser scanning microscopy.


Assuntos
Agrobacterium/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Toxinas Bacterianas/metabolismo , Cloroplastos/metabolismo , Endotoxinas/genética , Endotoxinas/metabolismo , Gossypium/genética , Proteínas Hemolisinas/genética , Proteínas Hemolisinas/metabolismo , Controle de Insetos/métodos , Resistência a Inseticidas/genética , Inseticidas/metabolismo , Controle Biológico de Vetores , Animais , Toxinas de Bacillus thuringiensis , Toxinas Bacterianas/genética , Gossypium/metabolismo , Gossypium/microbiologia , Insetos/metabolismo , Resistência a Inseticidas/efeitos dos fármacos , Inseticidas/farmacologia , Larva/metabolismo , Folhas de Planta/metabolismo , Plantas Geneticamente Modificadas , Transformação Genética
13.
Arch Virol ; 158(2): 505-10, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23065111

RESUMO

Though Catharanthus roseus (Madagascar periwinkle) is an ornamental plant, it is famous for its medicinal value. Its alkaloids are known for anti-cancerous properties, and this plant is studied mainly for its alkaloids. Here, this plant has been studied for its viral diseases. Complete DNA sequences of two begomoviruses infecting C. roseus originating from Pakistan were determined. The sequence of one begomovirus (clone KN4) shows the highest level of nucleotide sequence identity (86.5 %) to an unpublished virus, chili leaf curl India virus (ChiLCIV), and then (84.4 % identity) to papaya leaf curl virus (PaLCV), and thus represents a new species, for which the name "Catharanthus yellow mosaic virus" (CYMV) is proposed. The sequence of another begomovirus (clone KN6) shows the highest level of sequence identity (95.9 % to 99 %) to a newly reported virus from India, papaya leaf crumple virus (PaLCrV). Sequence analysis shows that KN4 and KN6 are recombinants of Pedilanthus leaf curl virus (PedLCV) and croton yellow vein mosaic virus (CrYVMV).


Assuntos
Begomovirus/genética , Catharanthus/virologia , DNA Viral/química , DNA Viral/genética , Genoma Viral , Doenças das Plantas/virologia , Begomovirus/isolamento & purificação , Análise por Conglomerados , Dados de Sequência Molecular , Paquistão , Filogenia , Análise de Sequência de DNA , Homologia de Sequência do Ácido Nucleico
14.
Electron. j. biotechnol ; 10(2): 240-251, Apr. 15, 2007. ilus, tab
Artigo em Inglês | LILACS | ID: lil-499177

RESUMO

Advanced generations of different transgenic lines of indica basmati rice (Basmati-370) expressing two unrelated Bt genes, cry1Ac and cry2A were evaluated for resistance to Yellow Stem Borer (YSB) and Rice Leaf Folder (RLF) under field conditions compared to control lines over three years (2003-2005). Homozygous lines were selected and analyzed for insect resistance, morphological, physiochemical properties and risk assessment studies. After artificial infestation of target insects, the transgenic plants showed significant resistance. Data were recorded in terms of dead hearts and white heads at vegetative and flowering stage respectively. Transgenic lines showed up to 100 and 96 percent resistance against yellow stem borer at vegetative and flowering stages, respectively. Natural damage of rice leaf folder was also observed during the year 2005. The transgenic plants were 98 percent more resistant as compared to untransformed control plants. Variations in some morphological characteristics, e.g., the average number of tillers, plant height and maturity were also observed. Transgenic lines produced 40 percent more grains than control plants. All these characteristics were stably inherited in advanced generations. The transgenic lines had no significant effect on non-target insects (insects belonging to orders other than Lepidoptera and Diptera) in field or under storage conditions. Chances of pollen-mediated gene flow were recorded at a rate of 0.14 percent.


Assuntos
Bacillus thuringiensis , Proteínas de Bactérias , Oryza/genética , Controle Biológico de Vetores , Plantas Geneticamente Modificadas/genética , Resistência a Inseticidas/genética , Adaptação Fisiológica/genética , Toxinas Bacterianas , Controle de Insetos , Larva , Mariposas/patogenicidade , Oryza/parasitologia , Medição de Risco , Segurança
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