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1.
J Basic Microbiol ; 60(6): 532-542, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32159865

RESUMO

Interaction of pretilachlor with photosystem (PS)-II of the cyanobacterium Desmonostoc muscorum PUPCCC 405.10 has been studied in this paper. Pretilachlor negatively affected growth, chlorophyll a (Chl a), photosynthesis, and carbon dissimilation in a dose-dependent manner. Effects were also observed in PSs, especially PS-II (an 11-35% decrease), as well as the whole photosynthetic electron transport activity. The fluorescence emission spectrum of Chl a revealed a dose-dependent effect of pretilachlor on both the antenna and the core complex of PSs, with more severe effect on the former. Data of O-J-I-P fluorescence transient of Chl a revealed that pretilachlor interfered with electron flow between QA and QB sites of PS-II. It was further observed that pretilachlor decreased maximum fluorescence, variable and relative variable fluorescence, maximum quantum yield, quantum yield of electron transport, the rate of trapped exciton movement, quantum yield of electron transfer, and performance index of primary photochemistry; however, there was a progressive increase in the net rate of PS-II closure, quantum yield of energy dissipation, and effective antenna size per active reaction center. A decrease in photosynthetic activity leads to a decrease in carbon dissimilation, as evidenced by low activity of glucose-6-phosphate dehydrogenase and pyruvate kinase. Thus, pretilachlor, which is otherwise known to kill weeds by interfering with cell division, affected the growth of the cyanobacteria by interacting with PS-II.


Assuntos
Acetanilidas/farmacologia , Cianobactérias/efeitos dos fármacos , Cianobactérias/metabolismo , Complexo de Proteína do Fotossistema II/metabolismo , Proteínas de Bactérias/metabolismo , Clorofila A/metabolismo , Cianobactérias/crescimento & desenvolvimento , Transporte de Elétrons/efeitos dos fármacos , Fluorescência , Glicogênio/metabolismo , Fotossíntese/efeitos dos fármacos
2.
J Arthroplasty ; 28(6): 1005-9, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23523497

RESUMO

Patients older than 55 years presenting with acetabular fractures fulfilling the criteria for acute total hip arthroplasty (THA) were included. Cementless THA was done using the Octopus System and autologous bone grafting. 15 patients were available for latest follow up. The average follow-up was 81.5 months (62-122 months). Mean Harris Hip Score was 91.1. 10 patients were walking without any support while 5 were using a cane. There were no cases of acetabular or femoral component loosening. This method of treatment is promising in the older population as there is deficiency of bone stock which may lead to fixation failures. It is, therefore, worthwhile to recommend primary THA using the Octopus system in the successful management of selected types of acetabular fractures in the elderly.


Assuntos
Acetábulo/lesões , Acetábulo/cirurgia , Artroplastia de Quadril/instrumentação , Artroplastia de Quadril/métodos , Fraturas Ósseas/cirurgia , Idoso , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Tempo
3.
J Assoc Physicians India ; 61(2): 114-6, 126, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24471250

RESUMO

OBJECTIVE: Primary objective of this study was to compare the efficacy of Prasugrel vs. Clopidogrel in the patients with acute coronary syndromes (ACS) undergoing percutaneous coronary intervention (PCI) by measuring inhibition of platelet aggregation after loading and maintenance dose of both the drugs. The patients were also assessed for safety of the drugs. METHODS: This was a randomised, double-blind, double-dummy, comparative, multicentric clinical trial in patients with acute coronary syndrome (unstable angina, non-ST elevation MI and ST elevation MI) undergoing PCI. The patients were randomly assigned to receive prasugrel (loading dose of 60 mg followed by maintenance dose of 10-mg once daily) or clopidogrel (loading dose of 300 mg followed by maintenance dose of 75 mg once daily) for a period of 12 weeks. All the patients were co-prescribed aspirin 325 mg with both the drugs. The primary efficacy end point in this study was percentage inhibition of ADP induced platelet aggregation (IPA) at 4 +/- 1 hours after the loading dose and at 30 +/- 3 days during maintenance treatment. The platelet aggregation of both the drugs was measured by whole blood aggregometer using 10 mmol of ADP as an aggregant. Though this study was not powered to see the difference in clinical efficacy parameters, the patients were observed for the incidence of nonfatal MI, nonfatal stroke, re-hospitalization, death, or need for urgent revascularization due to a cardiac ischemic event at days 30 and 90 during the study. The safety of study drugs were evaluated by incidence of major bleeding, reported adverse drug reaction and alterations of any laboratory parameters. RESULT: A total of 220 patients were enrolled at 11 centres across India. Ten patients were given the loading dose of prasugrel or clopidogrel but did not underwent PCI due to change in investigator's decision to go for PCI. Out of 210 eligible patients, 21 patients were discontinued during the study. 157 patients were evaluated for platelet inhibition after loading dose at 4 hours and 150 patients at day 30 during maintenance phase of antiplalelet therapy. The investigators could not perform this test in remaining patients due to urgency and criticality of the patients. 189 patients were observed for the incidence of nonfatal MI, nonfatal stroke, rehospitalisation, urgent revascularisation or death due to a cardiac ischemic event. All eligible patients who received at least a loading dose were evalauted for safety. In prasugrel group, 85 and 77 patients were evaluated for IPA at 4 hours and day 30 respectively whereas in clopdogrel group 72 and 73 patients were tested for IPA at 4 hours and at 30 days. Patients in prasugrel group have demonstrated significantly higher inhibition of platelets as compared to clopidogrel group (82.5% vs 71.1%) at 4 hours and at 30 days (84.1% vs 67.4%). The difference in inhibition of platelets between prasugrel and clopidogrel after loading dose and maintenenace dose was statistically significant (p < or = 0.01). The patients were also evaluated for drug hyporesponsiveness to antiplatelet therapy if IPA was < 20% at day 30 from the baseline. More patients on prasugrel have shown response to antiplatlet therapy than on clopidogrel (97.4% vs 87.6%). The difference between the two groups was statistically significant (p < 0.05). There was no difference observed during the study in the incidence of nonfatal MI, nonfatal stroke, death, rehospitalisation or need for urgent revascularisation due to a cardiac event between prasugrel and clopidogrel. Both the drugs were found to be to be well tolerated and have comparable safety profile. CONCLUSION: This study suggests that prasugrel is more effective than clopidogrel as an anti platelet drug as evident by inhibition of platelet aggregation. More patients on clopidogrel are likely to have poor response to therapy as compared to prasugrel. Both the drugs were well tolerated and have comparable safety profile.


Assuntos
Síndrome Coronariana Aguda/terapia , Piperazinas/uso terapêutico , Inibidores da Agregação Plaquetária/uso terapêutico , Antagonistas do Receptor Purinérgico P2Y/uso terapêutico , Tiofenos/uso terapêutico , Ticlopidina/análogos & derivados , Adulto , Idoso , Aspirina/uso terapêutico , Clopidogrel , Terapia Combinada , Método Duplo-Cego , Quimioterapia Combinada , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Intervenção Coronária Percutânea , Cloridrato de Prasugrel , Ticlopidina/uso terapêutico , Resultado do Tratamento
4.
Environ Sci Pollut Res Int ; 29(2): 2493-2509, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34370199

RESUMO

Wetlands are one of the most productive aquatic ecosystems on earth, and their water quality is an indicative of their suitability for maintaining various ecosystem services. In this study, different statistical techniques and water quality index (WQI) were employed to access the status and spatiotemporal patterns in water quality of seven selected (two natural and five manmade) wetlands of Punjab. The results revealed that the status of water quality in the selected wetlands was between good and poor during studied seasons (summer, monsoon, and winter) of year 2019. The principal component analysis identified three groups of wetlands with distinct water quality characteristics with spatial patterns: Kahnuwan Chhamb and Keshopur Miani having nearly similar values of pH, total dissolve salts, electrical conductivity, chemical oxygen demand, total alkalinity, bicarbonate and ammonium content; Ropar, Kanjli, and Harike having higher value of nutrients than the other wetlands; and Ranjit Sagar and Nangal with low value of measured water quality characteristics. Further, analysis of variance revealed that all analyzed water quality parameters showed temporal patterns in water quality except water pH, electrical conductivity, dissolved oxygen, biological oxygen demand, and phosphate content. This comparative study enhanced our knowledge about the spatiotemporal patterns in water quality and in the future will be helpful to the policymakers and concerned authorities for developing better water quality management strategies for these wetlands.


Assuntos
Poluentes Químicos da Água , Qualidade da Água , Ecossistema , Monitoramento Ambiental , Índia , Estações do Ano , Poluentes Químicos da Água/análise , Áreas Alagadas
5.
Physiol Plant ; 138(1): 74-90, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19825007

RESUMO

We have examined the role of gibberellins (GAs) in plant development by expression of the pea GA 2-oxidase2 (PsGA2ox2) cDNA, which encodes a GA inactivating enzyme, under the control of the MEDEA (MEA) promoter. Expression of MEA:PsGA2ox2 in Arabidopsis caused seed abortion, demonstrating that active GAs in the endosperm are essential for normal seed development. MEA:PsGA2ox2 plants had reduced ovule number per ovary and exhibited defects in phyllotaxy and leaf morphology which were partly suppressed by GA treatment. The leaf architecture and phyllotaxy defects of MEA:PsGA2ox2 plants were also restored by sly1-d which reduces DELLA protein stability to increase GA response. MEA:PsGA2ox2 seedlings had increased expression of the KNOTTED1-like homeobox (KNOX) genes, BP, KNAT2 and KNAT6, which are known to control plant architecture. The expression of KNOX genes is also altered in wild-type plants treated with GA. These results support the conclusion that GAs can suppress the effects of elevated KNOX gene expression, and raise the possibility that localized changes in GA levels caused by PsGA2ox2 alter the expression of KNOX genes to modify plant architecture.


Assuntos
Arabidopsis/crescimento & desenvolvimento , Giberelinas/metabolismo , Oxigenases de Função Mista/metabolismo , Pisum sativum/enzimologia , Proteínas de Plantas/metabolismo , Sementes/crescimento & desenvolvimento , Arabidopsis/genética , Arabidopsis/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Giberelinas/genética , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Oxigenases de Função Mista/genética , Pisum sativum/genética , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/ultraestrutura , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Plantas Geneticamente Modificadas/metabolismo , Regiões Promotoras Genéticas , Sementes/genética , Sementes/metabolismo
6.
PLoS One ; 14(9): e0221930, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31490970

RESUMO

Since carotenoids are important as natural colorants, antioxidants, neutraceutics and pharmaceutics, the aim of the present study was to find a new good source of these pigments. We hereby report a green microalga Asterarcys quadricellulare PUMCC 5.1.1 as a new and good producer of carotenoids. The organism produced 35±1.75 µg carotenoids mg-1 dry biomass during stationary phase in control cultures. The growth and carotenoids production by the test microalga were optimized by varying nutrient growth media, pH, nitrogen and phosphate source, salinity, light quality, intensity and duration. The optimized conditions for carotenoid production were: Bold basal (BB) medium with pH 8.5, containing with10 mM nitrate, 3.5 mM phosphate and 0.17 mM salinity and illuminated with blue light with 60 µmol m-2 s-1 photon flux light intensity. Cultivation of cultures in the above mentioned optimized conditions resulted in nearly 3.0 fold increase in carotenoid production compared to the control cultures grown in unmodified BB medium. Using HPTLC, four carotenoids have been identified as ß-carotene, lutein, astaxanthin and canthaxanthin. Further, carotenoids were also separated and purified by flash chromatography and the amounts of purified carotenoids were determined by HPLC. The organism produced 47.0, 28.7, 15.5 and 14.0 µg ß-carotene, lutein, astaxanthin and canthaxanthin mg-1 dry biomass, respectively, under optimized conditions. The amount of total carotenoids (118 µg mg-1 dry biomass) produced by Asterarcys quadricellulare PUMCC 5.1.1 under optimized culture conditions was significantly higher than control cultures. Thus, this microalgal strain is a promising candidate for carotenoid production at commercial level.


Assuntos
Carotenoides/metabolismo , Clorofíceas/crescimento & desenvolvimento , Clorofíceas/metabolismo , Técnicas de Cultura/métodos , Microalgas/crescimento & desenvolvimento , Microalgas/metabolismo , Carotenoides/isolamento & purificação
7.
Glob Heart ; 13(4): 267-274.e2, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30197242

RESUMO

BACKGROUND: Despite the high prevalence of rheumatic heart disease (RHD) in developing countries such as India, data on characteristics, complications, and treatment practices are lacking. The HP-RHD (Himachal Pradesh Rheumatic Heart Disease) registry aimed at reporting these parameters in patients with RHD from a northern state of India. METHODS: A total of 2,005 consecutive patients of RHD were enrolled over a period of 6 years (2011 to 2016) in the present study. The clinical characteristics, complications, and treatment practices were systematically recorded. RESULTS: The mean age for patients with RHD was 40.3 ± 14.3 (range 5 to 83 years). RHD predominantly affected females (72.3%) and population from rural background (92%). Multivalvular involvement was frequent (43.2%), mitral valve was the commonest affected valve (83.3%). The majority of the patients had moderate-to-severe valvular dysfunction (69.3%). Mitral and tricuspid valve involvement was more frequent in female subjects compared with more frequent aortic valve involvement in male subjects (p < 0.001). The major adverse cardiovascular events were recorded in 23.4% patients at the time of registry and comprised mainly advanced heart failure (15.6%), peripheral embolism (4.1%), and stroke (3.9%). The independent risk determinants of major adverse cardiovascular events (were advanced age (odds ratio [OR]: 1.01; 95% confidence interval [CI]: 1.00-1.02), severe mitral stenosis (OR: 1.73; 95% CI: 1.34-2.20), severe tricuspid regurgitation (OR: 2.11; 95% CI: 1.48-3.02), presence of pulmonary artery hypertension (OR: 1.33; 95% CI: 1.04-1.69), and atrial fibrillation (OR: 1.64; 95% CI: 1.28-2.11). Evidence-based use of oral anticoagulant therapy was documented in 77.7% of high-risk patients. Only 28.5% of study population was receiving secondary prophylaxis. CONCLUSIONS: Complications in patients with RHD increase with age and worsening valvular dysfunction. Programs focused on early detection and evidence-based management will assist in improving outcomes.


Assuntos
Antirreumáticos/uso terapêutico , Doenças das Valvas Cardíacas/prevenção & controle , Sistema de Registros , Cardiopatia Reumática/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Seguimentos , Doenças das Valvas Cardíacas/epidemiologia , Doenças das Valvas Cardíacas/etiologia , Humanos , Índia/epidemiologia , Pessoa de Meia-Idade , Prevalência , Prognóstico , Estudos Prospectivos , Cardiopatia Reumática/complicações , Cardiopatia Reumática/terapia , Fatores de Tempo , Adulto Jovem
8.
Int J Biol Macromol ; 102: 475-496, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28437766

RESUMO

Lectins are ubiquitous proteins/glycoproteins of non-immune origin that bind reversibly to carbohydrates in non-covalent and highly specific manner. These lectin-glycan interactions could be exploited for establishment of novel therapeutics, targeting the adherence stage of viruses and thus helpful in eliminating wide spread viral infections. Here the review focuses on the haemagglutination activity, carbohydrate specificity and characteristics of cyanobacterial lectins. Cyanobacterial lectins exhibiting high specificity towards mannose or complex glycans have potential role as anti-viral agents. Prospective role of cyanobacterial lectins in targeting various diseases of worldwide concern such as HIV, hepatitis, herpes, influenza and ebola viruses has been discussed extensively. The review also lays emphasis on recent studies involving structural analysis of glycan-lectin interactions which in turn influence their mechanism of action. Altogether, the promising approach of these cyanobacterial lectins provides insight into their use as antiviral agents.


Assuntos
Antivirais/química , Antivirais/farmacologia , Cianobactérias/química , Lectinas/química , Lectinas/farmacologia , Animais , Antivirais/metabolismo , Hemaglutinação , Humanos , Lectinas/metabolismo , Especificidade por Substrato
9.
BMJ Case Rep ; 20162016 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-26740271

RESUMO

Concomitant presentation of tuberculosis (TB) and lymphoma is a rare entity. A primary malignancy such as Hodgkin's disease (HD) may cause suppression of the cell-mediated immunity, which predisposes to a concomitant TB infection. We report a case of an 18-year-old man, who presented with fever and was found to have pallor, generalised lymphadenopathy, hepatosplenomegaly, ascites and pedal oedema. Ultrasound of the abdomen revealed enlarged lymph nodes in the para-aortic and peripancreatic region. On chest contrast-enhanced CT, calcified mediastinal lymph nodes were seen. A surgical biopsy of a cervical lymph node was performed, which revealed caseous necrosis surrounded by epithelioid cells along with diffuse nodal architectural effacement by large atypical lymphoid cells. Numerous Reed Sternberg cells were also seen. Immunohistochemistry confirmed diagnosis of Hodgkin's lymphoma. The same lymph node came out to be positive for mycobacterium TB on polymerised chain reaction. The patient was given antitubercular therapy concomitantly with chemotherapy for HD, and improved with treatment.


Assuntos
Doença de Hodgkin/complicações , Tuberculose dos Linfonodos/complicações , Adolescente , Biópsia , Doença de Hodgkin/patologia , Humanos , Imuno-Histoquímica , Linfonodos/patologia , Masculino , Pescoço/patologia , Células de Reed-Sternberg/patologia , Tomografia Computadorizada por Raios X , Tuberculose dos Linfonodos/patologia
10.
Orthopedics ; 34(2): 134, 2011 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-21323279

RESUMO

Management of neglected patellar tendon ruptures remains a difficult therapeutic endeavor, as complications such as adhesions, proximal patellar migration, and quadriceps contracture occur. Treatment goals include restoration of extensor mechanism, both structurally and functionally, which allows active knee extension. Few cases of neglected patellar tendon rupture have been reported in the literature, however, all have used preoperative or additional intraoperative procedures to relocate the patella or to provide additional support to the reconstructed tendon. This article presents a case of a 25-year-old man whose diagnosis of patellar tendon rupture was delayed by 1 year. The patella was mobile and could be brought down to its original position manually. The patellar tendon was successfully reconstructed with autogenous semitendinosus and gracilis tendon graft. No preoperative or intraoperative traction was used on the patella. Quadriceps lengthening was not performed and no hardware was used between the patella and the tibia to augment the reconstruction. Scar tissue was not excised and was used to cover the hamstring tendons. The patient achieved a good functional result after 5 months of rehabilitation. At 14-month follow-up, the patient had returned to his pre-injury level of work with no deterioration of knee function.


Assuntos
Tecido Adiposo/cirurgia , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Ligamento Patelar/lesões , Ligamento Patelar/cirurgia , Adulto , Humanos , Masculino , Ruptura/cirurgia , Resultado do Tratamento
13.
J Agric Food Chem ; 58(16): 9181-9, 2010 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-23654242

RESUMO

Plant cell wall structure integrity and associated tissue mechanical properties is one of key determinants for the perceived texture of plant-based foods. Carrots (Daucus carota) were used to investigate the effect of mineral supply of boron (B) and/or calcium (Ca), during plant growth, on the plant cell wall structure and mechanical properties of matured root tissues. Five commercial cultivars of carrots, Kuroda (orange), Dragon Purple, Kuttiger White, Yellow, and Nutri-Red, were cultivated under controlled glasshouse conditions over two seasons. Significant increases in the accumulation of B and Ca were found for all cultivars of carrots when additional B and Ca were included in the nutrient feeding solutions throughout the plant growth period. Elevated levels of B in carrot root tissue reduced the uptake of Ca and other mineral nutrients and enhanced plant cell wall structural integrity, its resistance to fracture, and the weight and size (both diameter and length) of carrots. Although higher amounts of Ca were accumulated in the plant materials, the additional supply of Ca did not have a significant effect on the mechanical properties of mature plant tissues or on the uptake of B by the plant. The results suggest that B cross-linking of pectin (rhamnogalacturonan II) has a greater influence on mature tissue mechanical properties than Ca cross-linking of pectin (homogalacturonan) when supplied during plant growth.


Assuntos
Boro/química , Parede Celular/química , Daucus carota/química , Cálcio/química , Daucus carota/citologia
14.
J Agric Food Chem ; 58(3): 1732-40, 2010 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-20067287

RESUMO

Fresh and stored melons were analyzed for total and bioaccessible beta-carotene content, as well as total antioxidant potentials, to investigate the effects of genotype, season, sowing time, and storage on nutritional quality. There were significant cultivar effects on beta-carotene content (P < 0.001), ranging from 1 to 23 mg kg(-1) of fresh weight (FW), its bioaccessibility (P < 0.005), ranging from 79 to 94.5%, and for antioxidant potential (P < 0.001), ranging from 1569 to 2267 micromol of Fe(2+) kg(-1) of FW of melons. Sowing time significantly affected beta-carotene contents (P < 0.017) and antioxidant potentials (P < 0.001), but these were highly cultivar dependent, with season having no effect. Postharvest storage over 4 weeks at 7 degrees C resulted in losses of antioxidant potential and beta-carotene content independent of cultivar. Cultivar and postharvest management were major determinants of nutritional quality of the melons evaluated.


Assuntos
Antioxidantes/análise , Cucurbitaceae/química , Manipulação de Alimentos/métodos , Extratos Vegetais/análise , beta Caroteno/análise , Antioxidantes/metabolismo , Disponibilidade Biológica , Digestão , Modelos Biológicos , Extratos Vegetais/metabolismo , beta Caroteno/metabolismo
15.
Planta ; 229(3): 523-37, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19011896

RESUMO

SPINDLY (SPY) is an important regulator of plant development, and consists of an N-half tetratricopeptide repeat (TPR) domain containing 10 TPR motifs and a C-half catalytic domain, similar to O-GlcNAc transferase (OGT) of animals. The best characterised role of SPY is a negative regulator of GA signalling, and all known spy alleles have been isolated based on increased GA response. Of the eight alleles that directly affect the TPR domain, all alter TPRs 6, 8 and/or 9. To test the hypothesis that a subset of TPRs, including 6, 8 and 9, are both essential and sufficient for the regulation of GA response, we overexpressed the full-length barley (Hordeum vulgare L.) SPY protein (HvSPY) and several deletion mutants in barley aleurone cells and in Arabidopsis wild type (WT) and spy-4 plants. Transient assays in barley aleurone cells, that also express endogenous HvSPY, demonstrated that introduced HvSPY and HvTPR inhibited GA(3)-induced alpha-amylase expression. With the exception of HvSPYDelta1-5, the other deletion proteins were partially active in the barley assay, including HvSPYDelta6-9 which lacks TPRs 6, 8 and 9. In Arabidopsis, analysis of seed germination under a range of conditions revealed that 35S:HvSPY increased seed dormancy. Hvspy-2, which lacks parts of the eighth and ninth TPRs, was able to partially complement all aspects of the spy-4 phenotype. In the presence of AtSPY, 35S:HvTPR caused some phenotypes consistent with a decrease in GA signalling, including increased seed sensitivity to paclobutrazol and delayed flowering. These plants also possessed distorted leaf morphology and altered epidermal cell shape. Thus, despite genetic analysis demonstrating that TPRs 6, 8 and 9 are required for regulation of GA signalling, our results suggest that these TPRs are neither absolutely essential nor sufficient for SPY activity.


Assuntos
Arabidopsis/metabolismo , Giberelinas/farmacologia , Hordeum/metabolismo , Proteínas de Plantas/fisiologia , Proteínas Repressoras/fisiologia , Alelos , Arabidopsis/efeitos dos fármacos , Arabidopsis/genética , Deleção de Genes , Germinação/genética , Glucuronidase/análise , Hordeum/efeitos dos fármacos , Hordeum/fisiologia , Fenótipo , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Sementes/genética , Sementes/crescimento & desenvolvimento , Sementes/metabolismo , Transdução de Sinais/genética , Temperatura
16.
Funct Plant Biol ; 34(12): 1055-1060, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32689435

RESUMO

Genetic modification (GM) of plants has great potential in the production of food and industrial compounds, and in molecular pharming. One of the greatest public concerns regarding this technology is effective pollen flow, in which wind- or insect-borne transgenic pollen is able to fertilise either non-GM crops of the same species, or closely related weed species, and lead to viable seed formation. In this paper we describe a novel concept, based on epigenetic inheritance (imprinting) and post-transcriptional gene silencing (PTGS)/RNA interference (RNAi), designed to prevent transgene escape via pollen flow from transgenic plants. A key advantage of this strategy is that it would allow all seeds from self-pollinated transgenic plants to be harvested and re-sown, without the need for specific treatments, while retaining all of the transgenes present in the parent. Thus, this strategy is not a Genetic Use Restriction Technology (GURT) and if implemented would not prevent seed saving by end-users.

17.
Plant Mol Biol ; 50(4-5): 773-88, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12374307

RESUMO

The Arabidopsis thaliana genome has two genes (AtFC-I and AtFC-II), encoding ferrochelatase, the terminal enzyme of haem biosynthesis. The roles of the two enzymes in the synthesis of haem for different haemoproteins was investigated using reporter gene analysis. A 1.41 kb fragment from the 5' upstream region of the AtFC-II gene was fused to the luciferase gene, and then introduced into tobacco plants, followed by luciferase activity measurements. AtFC-II-LUCwas expressed in all aerial parts of the plant, and was highest in flowers, but it was not expressed in roots. It was unaffected by viral infection, and considerably reduced by wounding or oxidative stress. Similarly, a 1.76 kb region of the AtFC-I promoter was fused to the uidA gene encoding beta-glucuronidase. AtFC-I-GUS was expressed in all tissues of the plant, but was higher in roots and flowers than in leaves or stems. It was induced by sucrose, wounding and oxidative stress and, most markedly, by plants undergoing the hypersensitive response to TMV infection. Levels of endogenous ferrochelatase activity were increased in pea chloroplasts isolated from wounded leaves, indicating that the induction in promoter activity is likely to result in increased haem biosynthetic potential. Salicylic acid, but not methyl-jasmonate was able to replace the stress treatment in induction of AtFC-I expression, suggesting that the requirement for haem synthesis is part of the defence response. The implications of the results for the different roles of the two ferrochelatases in haem biosynthesis are discussed.


Assuntos
Arabidopsis/enzimologia , Ferroquelatase/genética , Heme/biossíntese , Acetatos/farmacologia , Arabidopsis/genética , Ácido Araquidônico/farmacologia , Ciclopentanos/farmacologia , Relação Dose-Resposta a Droga , Ferroquelatase/metabolismo , Flores/enzimologia , Flores/genética , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Glucuronidase/genética , Glucuronidase/metabolismo , Peróxido de Hidrogênio/farmacologia , Luciferases/genética , Luciferases/metabolismo , Estresse Oxidativo , Oxilipinas , Folhas de Planta/enzimologia , Folhas de Planta/genética , Raízes de Plantas/enzimologia , Raízes de Plantas/genética , Caules de Planta/enzimologia , Caules de Planta/genética , Plantas Geneticamente Modificadas , Regiões Promotoras Genéticas/genética , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Ácido Salicílico/farmacologia , Estresse Mecânico , Sacarose/farmacologia
18.
J Biol Chem ; 277(7): 4731-7, 2002 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-11675381

RESUMO

Ferrochelatase catalyzes the insertion of Fe(2+) into protoporphyrin IX to generate protoheme. In higher plants, there is evidence for two isoforms of this enzyme that fulfill different roles. Here, we describe the isolation of a second ferrochelatase cDNA from cucumber (CsFeC2) that was less similar to a previously isolated isoform (CsFeC1) than it was to some ferrochelatases from other higher plants. In in vitro import experiments, the two cucumber isoforms showed characteristics similar to their respective ferrochelatase counterparts of Arabidopsis thaliana. The C-terminal region of CsFeC2 but not CsFeC1 contained a conserved motif found in light-harvesting chlorophyll proteins, and CsFeC2 belonged to a phylogenetic group of plant ferrochelatases containing this conserved motif. We demonstrate that CsFeC2 was localized predominantly in thylakoid membranes as an intrinsic protein, and forming complexes probably with the C-terminal conserved motif, but a minor portion was also detected in envelope membranes. CsFeC2 mRNA was detected in all tissues and was light-responsive in cotyledons, whereas CsFeC1 mRNA was detected in nonphotosynthetic tissues and was not light-responsive. Interestingly, tissue-, light-, and cycloheximide-dependent expressions of the two isoforms of ferrochelatase were similar to those of two glutamyl-tRNA reductase isoforms involved in the early step of tetrapyrrole biosynthesis, suggesting the existence of distinctly controlled tetrapyrrole biosynthetic pathways in photosynthetic and nonphotosynthetic tissues.


Assuntos
Ferroquelatase/química , Regulação da Expressão Gênica de Plantas , Fotossíntese , Aldeído Oxirredutases/química , Motivos de Aminoácidos , Sequência de Aminoácidos , Animais , Arabidopsis/enzimologia , Northern Blotting , Western Blotting , Clonagem Molecular , Sequência Conservada , Cucumis sativus/enzimologia , Cicloeximida/farmacologia , DNA Complementar/metabolismo , Eletroforese em Gel de Poliacrilamida , Ferroquelatase/biossíntese , Ferroquelatase/genética , Vetores Genéticos , Glutationa Transferase/metabolismo , Dados de Sequência Molecular , Mutação , Pisum sativum , Filogenia , Isoformas de Proteínas , Precursores de Proteínas/metabolismo , Estrutura Terciária de Proteína , Inibidores da Síntese de Proteínas/farmacologia , RNA Mensageiro/metabolismo , Frações Subcelulares , Tilacoides/metabolismo , Fatores de Tempo , Distribuição Tecidual
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