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1.
Biochem J ; 477(17): 3417-3431, 2020 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-32856714

RESUMO

Cyanide-resistant alternative oxidase (AOX) is a nuclear-encoded quinol oxidase located in the inner mitochondrial membrane. Although the quality control of AOX proteins is expected to have a role in elevated respiration in mitochondria, it remains unclear whether thermogenic plants possess molecular mechanisms for the mitochondrial degradation of AOX. To better understand the mechanism of AOX turnover in mitochondria, we performed a series of in organello AOX degradation assays using mitochondria from various stages of the appendices of Arum maculatum. Our analyses clearly indicated that AOX proteins at certain stages in the appendices are degraded at 30°C, which is close to the maximum appendix temperature observed during thermogenesis. Interestingly, such temperature-dependent protease activities were specifically inhibited by E-64, a cysteine protease inhibitor. Moreover, purification and subsequent nano LC-MS/MS analyses of E-64-sensitive and DCG-04-labeled active mitochondrial protease revealed an ∼30 kDa protein with an identical partial peptide sequence to the cysteine protease 1-like protein from Phoenix dactylifera. Our data collectively suggest that AOX is a potential target for temperature-dependent E-64-sensitive cysteine protease in the appendices of A. maculatum. A possible retrograde signalling cascade mediated by specific degradation of AOX proteins and its physiological significance are discussed.


Assuntos
Arum/enzimologia , Mitocôndrias/enzimologia , Proteínas Mitocondriais/metabolismo , Oxirredutases/metabolismo , Proteínas de Plantas/metabolismo , Proteólise , Transdução de Sinais , Arum/genética , Mitocôndrias/genética , Proteínas Mitocondriais/genética , Oxirredutases/genética , Proteínas de Plantas/genética
2.
Eur J Pediatr ; 179(10): 1553-1557, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32296984

RESUMO

The Arum palaestinum plant is one of the 26 species of the Arum genus of the Araceae family. This plant species is found through the Mediterranean region, Western Asia, and Europe. The leaves and seeds of the plant contain needle-shaped oxalate crystals that can irritate the affected tissue (skin, oral cavity, or GI tract) upon exposure. Up to this date, there is no available literature supporting the epidemiology or the clinical manifestations of poisoning by this plant. We retrospectively reviewed all Arum palaestinum exposures to children younger than 18 years of age reported to the Israel National Poison Information Center during 2017 from the IPIC computerized data system. We extracted demographic data and clinical data from those digital files. We reviewed the files of 53 patients' files and found slight male predominance (58% vs. 42%), and the age of exposure ranged from 9 month to 15 years. The main site of exposure was at home in most cases (47%) followed by outdoor exposure in 40% of the cases. In 66% of the cases, minor clinical manifestations were reported, mainly erythema and mouth irritation, agitation, and drooling. Asymptomatic patients composed 34% of the cases. In 17% of the cases, patients were recommended to visit an ambulatory facility, and other 15% of the cases were referred to the emergency department. There were no cases of severe poisoning, upper airways compromise, or death.Conclusion: Poisoning by Arum palaestinum is one of the most common pediatric plant poisoning in Israel. Our study supports with clinical data for the first time that this poisoning is self-limited, confined to the affected mucosa, and most likely does not necessitate any intervention. What is Known • A. palaestinum poisoning is one of the most common pediatric plant poisoning in Israel. • The leaves and seeds of the plant contain needle-shaped oxalates crystals. What is New • Pediatric exposure to A. palaestinum usually causes only mild and self-limited poisoning. • Expectant observation is the preferred management of such exposure.


Assuntos
Arum , Envenenamento , Adolescente , Criança , Pré-Escolar , Europa (Continente) , Feminino , Humanos , Lactente , Israel/epidemiologia , Masculino , Centros de Controle de Intoxicações , Estudos Retrospectivos
3.
Microrna ; 9(3): 224-231, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31622226

RESUMO

BACKGROUND: Arum conophalloides (A. conophalloides) is a wild edible delicate plant, widely used in traditional medicine. OBJECTIVE: This study aimed to examine the effects of A. conophalloides extracts on biochemical, molecular, and histopathological changes in the rat. METHODS: Fifty adult male Sprague-Dawley rats were divided into 5 groups (10 each) as follows: G1 or control, received distilled water; G2 and G3, treated with the aqueous extract at doses of 200 and 400 mg/kg; G4 and G5, treated with the hydroalcoholic extract at doses of 200 and 400 mg/kg. Prior to and at the end of the experiments, the serum levels of biochemistry parameters and the relative expression of miR-122 were assessed. Moreover, the liver and kidney tissues were examined microscopically. RESULTS: Liver and kidney tissues showed normal structure in all groups. There were no significant changes in biochemical indices or the expression of miR-122 in the extract-treated groups at the dose of 200 mg/kg. However, the group that received the aqueous extract at the dose of 400 mg/kg exhibited a significantly lower level of HDL, LDL, ALT, and ALP in comparison to the control. Additionally, miR-122 expression in this group exhibited a 10-fold increase (P=0.009). CONCLUSION: The serum level of hepatocyte-specific miR-122 will be more helpful in detecting hepatic changes in early stages than ALT and AST activity or histopathological evaluations of liver sections. Our findings highlight the potential hepatotoxicity of A. conophalloides aqueous extract in a rat model.


Assuntos
Arum/química , Doença Hepática Induzida por Substâncias e Drogas/patologia , MicroRNAs/genética , Extratos Vegetais/efeitos adversos , Alanina Transaminase/metabolismo , Animais , Aspartato Aminotransferases/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/genética , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Lipoproteínas HDL/metabolismo , Lipoproteínas LDL/metabolismo , Masculino , Extratos Vegetais/química , Ratos , Ratos Sprague-Dawley , Regulação para Cima
4.
Biomed Chromatogr ; 33(8): e4560, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31016743

RESUMO

Glutathione reductase (GR, E.C. 1.8.1.7), a flavoenzyme, is responsible for recycling of oxidized glutathione disulfide. This study was performed in two main sections. In the first GR was purified from bovine liver by affinity column chromatography and the purification rate and specific activity of the enzyme were calculated as 1832-fold and 141 EU/mg protein, respectively. The subunit molecular weight of the enzyme was determined as 55 kDa by means of SDS-PAGE. The second section isolated natural components of Arum rupicola Boiss. var. rupicola using column chromatography. The isolation protocol for this plant was performed with a series of different-sized columns with hexane-ethyl acetate. According to the thin-layer chromatography plate, seven substances (R1-R7) were isolated. Our study's aim was to find new activators or inhibitors for GR activity. With this aim, all isolated substances were tested for GR activity. R6 showed competitive inhibition, while R4 had noncompetitive inhibition of GR activity. R1 played a role as an activator of GR activity. The inhibitory activity percentage vs. concentration graph was plotted. Values of IC50 for R4 and R6 were calculated as 0.193 mg/mL and 3.98 µg/mL, respectively, from the equation of this graph.


Assuntos
Arum/química , Glutationa Redutase , Fígado/enzimologia , Extratos Vegetais/farmacologia , Animais , Bovinos , Cromatografia de Afinidade , Eletroforese em Gel de Poliacrilamida , Cromatografia Gasosa-Espectrometria de Massas , Glutationa Redutase/química , Glutationa Redutase/efeitos dos fármacos , Glutationa Redutase/isolamento & purificação , Glutationa Redutase/metabolismo , Fígado/química , Extratos Vegetais/química
5.
Sci Rep ; 8(1): 12163, 2018 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-30111862

RESUMO

Head and neck squamous cell carcinoma (HNSCC) is associated with low survival, and the current aggressive therapies result in high morbidity. Nutraceuticals are dietary compounds with few side effects. However, limited antitumor efficacy has restricted their application for cancer therapy. Here, we examine combining nutraceuticals, establishing a combination therapy that is more potent than any singular component, and delineate the mechanism of action. Three formulations were tested: GZ17-S (combined plant extracts from Arum palaestinum, Peganum harmala and Curcuma longa); GZ17-05.00 (16 synthetic components of GZ17-S); and GZ17-6.02 (3 synthetic components of GZ17S; curcumin, harmine and isovanillin). We tested the formulations on HNSCC proliferation, migration, invasion, angiogenesis, macrophage viability and infiltration into the tumor and tumor apoptosis. GZ17-6.02, the most effective formulation, significantly reduced in vitro assessments of HNSCC progression. When combined with cisplatin, GZ17-6.02 enhanced anti-proliferative effects. Molecular signaling cascades inhibited by GZ17-6.02 include EGFR, ERK1/2, and AKT, and molecular docking analyses demonstrate GZ17-6.02 components bind at distinct binding sites. GZ17-6.02 significantly inhibited growth of HNSCC cell line, patient-derived xenografts, and murine syngeneic tumors in vivo (P < 0.001). We demonstrate GZ17-6.02 as a highly effective plant extract combination and pave the way for future clinical application in HNSCC.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Extratos Vegetais/farmacologia , Carcinoma de Células Escamosas de Cabeça e Pescoço/tratamento farmacológico , Animais , Antineoplásicos/metabolismo , Apoptose/efeitos dos fármacos , Arum , Benzaldeídos/farmacologia , Carcinoma de Células Escamosas/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Cisplatino/farmacologia , Terapia Combinada , Curcuma , Curcumina/farmacologia , Suplementos Nutricionais , Receptores ErbB/metabolismo , Harmina/farmacologia , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Humanos , Camundongos , Camundongos Nus , Simulação de Acoplamento Molecular , Peganum , Transdução de Sinais/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
6.
Plant Biol (Stuttg) ; 20(2): 346-356, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29181866

RESUMO

Knowledge on the metabolism of polysaccharide reserves in wild species is still scarce. In natural sites we collected tubers of Arum italicum Mill. and A. maculatum L. - two geophytes with different apparent phenological timing, ecology and chorology - during five stages of the annual cycle in order to understand patterns of reserve accumulation and degradation. Both the entire tuber and its proximal and distal to shoot portion were utilised. Pools of non-structural carbohydrates (glucose, sucrose and starch), glucose-6-phosphate and ATP were analysed as important markers of carbohydrate metabolism. In both species, starch and glucose content of the whole tuber significantly increased from sprouting to the maturation/senescence stages, whereas sucrose showed an opposite trend; ATP and glucose-6-phosphate were almost stable and dropped only at the end of the annual cycle. Considering the two different portions of the tuber, both ATP and glucose-6-phosphate concentrations were higher in proximity to the shoot in all seasonal stages, except the flowering stage. Our findings suggest that seasonal carbon partitioning in the underground organ is driven by phenology and occurs independently of seasonal climate conditions. Moreover, our results show that starch degradation, sustained by elevated ATP and glucose-6-phosphate pools, starts in the peripheral, proximal-to-shoot portion of the tuber, consuming starch accumulated in the previous season, as a 'Last In-First Out' mechanism of carbohydrate storage.


Assuntos
Trifosfato de Adenosina/fisiologia , Arum/fisiologia , Carboidratos/fisiologia , Glucose-6-Fosfato/fisiologia , Tubérculos/fisiologia , Trifosfato de Adenosina/análise , Arum/química , Carboidratos/análise , Glucose/análise , Glucose/fisiologia , Glucose-6-Fosfato/análise , Brotos de Planta/química , Brotos de Planta/fisiologia , Tubérculos/química , Estações do Ano , Amido/análise , Amido/fisiologia , Sacarose/análise , Sacarose/metabolismo
7.
Funct Plant Biol ; 45(12): 1195-1204, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-32291010

RESUMO

Arum concinnatum Schott is a highly thermogenic species, with the temperature of the appendix exceeding ~10.9°C above the ambient temperature during thermogenesis, whereas the rates of respiration of the male florets in intact inflorescences peak at 0.92µmol s-1 g-1, which is the highest rate so far measured among the plants. Here, we attempt the ex situ exogenous induction of thermogenesis in whole inflorescences and in separate appendices of the spadix, and explore the thermogenic patterns under controlled laboratory conditions of light and temperature. Mature but unopened inflorescences and appendices showed thermogenic responses when treated with salicylic acid (SA), but not when treated with distilled water (control). With regard to light conditions, the responses revealed only one significant difference for inflorescences, which concerns the higher maximum temperature in the continuous light treatment compared with continuous dark. Along the ambient temperature gradient, at the lowest temperature edge individuals remained stable close to ambient temperature and to control. These findings suggest that, in general, ex situ exogenous induction of thermogenesis can be achieved in whole inflorescences and in separate appendices of spadix of A. concinnatum using SA. This study also indicates that SA acts independently of light conditions, while exogenous induction of thermogenesis takes place within an ambient temperature range.


Assuntos
Arum , Flores , Masculino , Ácido Salicílico , Temperatura , Termogênese
8.
Bioresour Technol ; 218: 1157-62, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27469097

RESUMO

Wet torrefaction of duckweed was carried out in the temperature range of 130-250°C to evaluate the effects on physicochemical properties and combustion behavior. The physicochemical properties of duckweed samples were investigated by ultimate analysis, proximate analysis, FTIR, XRD and SEM techniques. It was found that wet torrefaction improved the fuel characteristics of duckweed samples resulting from the increase in fixed carbon content, HHVs and the decrease in nitrogen and sulfur content and atomic ratios of O/C and H/C. It can be seen from the results of FTIR, XRD and SEM analyses that the dehydration, decarboxylation, solid-solid conversion, and condensation polymerization reactions were underwent during wet torrefaction. In addition, the results of thermogravimetric analysis (TGA) in air indicated that wet torrefaction resulted in significant changes on combustion behavior and combustion kinetics parameters. Duckweed samples after wet torrefaction behaved more char-like and gave better combustion characteristics than raw sample.


Assuntos
Arum/química , Biomassa , Cinética
9.
Nat Prod Res ; 30(16): 1777-86, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26284613

RESUMO

Arum dioscoridis and A. palaestinum (Araceae) are indigenous plant species in Jordan. HPLC-MS analysis of A. dioscoridis revealed the presence of apigenin, luteolin, quercetin, quercetin-3-O-ß-glucoside, vitexin, isoorientin, esculin, and caffeic and ferulic acids. Both Arum spp., influenced gastrointestinal carbohydrate and lipid digestion and absorption. Orlistat inhibited dose dependently and highly substantially pancreatic lipase (PL) in vitro. Similar to orlistat, Arum species aqueous extracts (AEs), apigenin, caffeic acid and esculin exhibited a concentration related PL inhibition. Comparable to acarbose, dual inhibition of α-amylase/α-glucosidase was observed for both Arum species. Like guar gum, A. dioscoridis AE minimised substantially area under 24 h glucose curve. Acute starch-induced postprandial hyperglycaemia in overnight fasting rats was highly significantly (p < 0.001) decreased by A. dioscoridis AE. A. palaestinum could not perform effectively in either starch- or glucose-fed fasting rats. No antiproliferative effects against colorectal cancer cell lines HT29, HCT116 and SW620 were detected for tested Arum spp.


Assuntos
Arum/química , Acarbose/farmacologia , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Neoplasias Colorretais , Inibidores de Glicosídeo Hidrolases/farmacologia , Células HT29 , Humanos , Hiperglicemia/tratamento farmacológico , Jordânia , Extratos Vegetais/farmacologia , Ratos , alfa-Amilases/antagonistas & inibidores , alfa-Glucosidases
10.
Oecologia ; 180(2): 439-51, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26552380

RESUMO

Hybridisation is common in plants and can affect the genetic diversity and ecology of sympatric parental populations. Hybrids may resemble the parental species in their ecology, leading to competition and/or gene introgression; alternatively, they may diverge from the parental phenotypes, possibly leading to the colonisation of new ecological niches and to speciation. Here, we describe inflorescence morphology, ploidy levels, pollinator attractive scents, and pollinator guilds of natural hybrids of Arum italicum and A. maculatum (Araceae) from a site with sympatric parental populations in southern France to determine how these traits affect the hybrid pollination ecology. Hybrids were characterised by inflorescences with a size and a number of flowers more similar to A. italicum than to A. maculatum. In most cases, hybrid stamens were purple, as in A. maculatum, and spadix appendices yellow, as in A. italicum. Hybrid floral scent was closer to that of A. italicum, but shared some compounds with A. maculatum and comprised unique compounds. Also, the pollinator guild of the hybrids was similar to that of A. italicum. Nevertheless, the hybrids attracted a high proportion of individuals of the main pollinator of A. maculatum. We discuss the effects of hybridisation in sympatric parental zones in which hybrids exhibit low levels of reproductive success, the establishment of reproductive barriers between parental species, the role of the composition of floral attractive scents in the differential attraction of pollinators and in the competition between hybrids and their parental species, and the potential of hybridisation to give rise to new independent lineages.


Assuntos
Arum/genética , Flores , Hibridização Genética , Fenótipo , Polinização , Animais , Ecologia , Flores/anatomia & histologia , França , Inflorescência , Insetos , Odorantes , Feromônios , Ploidias , Reprodução , Especificidade da Espécie
11.
Cancer ; 122(4): 598-610, 2016 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-26599199

RESUMO

BACKGROUND: The authors assessed the use of herbal medicine by Middle Eastern patients with cancer, as reported by their oncology health care professionals (HCPs). Herbal products identified by the study HCPs were evaluated for potential negative effects. METHODS: Oncology HCPs from 16 Middle Eastern countries received a 17-item questionnaire asking them to list 5 herbal products in use by their patients with cancer. A literature search (PubMed, Micromedex, AltMedDex, and the Natural Medicine Comprehensive Database) was conducted to identify safety-related concerns associated with the products listed. RESULTS: A total of 339 HCPs completed the study questionnaire (response rate of 80.3%), identifying 44 herbal and 3 nonherbal nutritional supplements. Safety-related concerns were associated with 29 products, including herb-drug interactions with altered pharmacodynamics (15 herbs), direct toxic effects (18 herbs), and increased in vitro response of cancer cells to chemotherapy (7 herbs). CONCLUSIONS: Herbal medicine use, which is prevalent in Middle Eastern countries, has several potentially negative effects that include direct toxic effects, negative interactions with anticancer drugs, and increased chemosensitivity of cancer cells, requiring a reduction in dose-density. Oncology HCPs working in countries in which herbal medicine use is prevalent need to better understand the implications of this practice. The presence of integrative physicians with training in complementary and traditional medicine can help patients and their HCPs reach an informed decision regarding the safety and effective use of these products.


Assuntos
Antineoplásicos/uso terapêutico , Interações Ervas-Drogas , Oncologia , Neoplasias/tratamento farmacológico , Fitoterapia/estatística & dados numéricos , Preparações de Plantas/efeitos adversos , Adulto , Pessoal Técnico de Saúde , Animais , Arum , Camelus , Curcuma , Daucus carota , Feminino , Alho , Medicina Herbária/estatística & dados numéricos , Mel , Humanos , Masculino , Pessoa de Meia-Idade , Oriente Médio , Leite , Nigella sativa , Médicos , Preparações de Plantas/uso terapêutico , Pesquisadores , Inquéritos e Questionários , Urtica dioica
12.
BMC Complement Altern Med ; 15: 264, 2015 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-26243305

RESUMO

BACKGROUND: Arum palaestinum is a plant commonly found in the Middle East that is ingested as an herbal remedy to fight cancer. However, no studies have examined the direct effect of the plant/plant extract on tumor growth in an animal model. METHODS: Verified prostate cancer cells were plated as 3D spheroids to determine the effect of extract from boiled Arum Palaestinum Boiss roots. In addition, male NU/NU mice (8 weeks old) with xenograft tumors derived from the prostate cancer cell line were treated daily with 1000 mg/kg body weight gavage of the suspension GZ17. The tumor growth was measured repeatedly with calipers and the excised tumors were weighed at the termination of the 3 week study. Control mice (10 mice in each group) received vehicle in the same manner and volume. RESULTS: The number of live prostate cancer cells declined in a dose/dependent manner with a 24 h exposure to the extract at doses of 0.015 to 6.25 mg/mL. A fortified version of the extract (referred to as GZ17) that contained higher levels of isovanillin, linolenic acid and ß-sitosterol had a stronger effect on the cell death rate, shifting the percentage of dead cells from 30 % to 55 % at the highest dose while the vehicle control had no effect on cell numbers. When GZ17 was applied to non-cancer tissue, in this case, human islets, there was no cell death at doses that were toxic to treated cancer cells. Preliminary toxicity studies were conducted on rats using an up-down design, with no signs of toxic effect at the highest dose. NU/NU mice with xenograft prostate tumors treated with GZ17 had a dramatic inhibition of tumor progression, while tumors in the control group grew steadily through the 3 weeks. The rate of tumor volume increase was 73 mm(3)/day for the vehicle group and 24 mm(3)/day for the GZ17 treated mice. While there was a trend towards lower excised tumor weight at study termination in the GZ17 treatment group, there was no statistical difference. CONCLUSIONS: Fortified Arum palaestinum Boiss caused a reduction in live cells within prostate cancer spheroids and blocked tumor growth in xenografted prostate tumors in mice without signs of toxicity.


Assuntos
Antineoplásicos , Arum/química , Benzaldeídos , Extratos Vegetais , Neoplasias da Próstata , Sitosteroides , Ácido alfa-Linoleico , Animais , Antineoplásicos/química , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Benzaldeídos/química , Benzaldeídos/farmacologia , Benzaldeídos/uso terapêutico , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Masculino , Camundongos , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/patologia , Ratos , Sitosteroides/química , Sitosteroides/farmacologia , Sitosteroides/uso terapêutico , Esferoides Celulares , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto , Ácido alfa-Linoleico/química , Ácido alfa-Linoleico/farmacologia , Ácido alfa-Linoleico/uso terapêutico
13.
Sci Rep ; 5: 8753, 2015 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-25736477

RESUMO

Several plant species can generate enough heat to increase their internal floral temperature above ambient temperature. Among thermogenic plants, Arum concinnatum shows the highest respiration activity during thermogenesis. However, an overall understanding of the genes related to plant thermogenesis has not yet been achieved. In this study, we performed de novo transcriptome analysis of flower organs in A. concinnatum. The de novo transcriptome assembly represented, in total, 158,490 non-redundant transcripts, and 53,315 of those showed significant homology with known genes. To explore genes associated with thermogenesis, we filtered 1266 transcripts that showed a significant correlation between expression pattern and the temperature trend of each sample. We confirmed five putative alternative oxidase transcripts were included in filtered transcripts as expected. An enrichment analysis of the Gene Ontology terms for the filtered transcripts suggested over-representation of genes involved in 1-deoxy-D-xylulose-5-phosphate synthase (DXS) activity. The expression profiles of DXS transcripts in the methyl-D-erythritol 4-phosphate (MEP) pathway were significantly correlated with thermogenic levels. Our results suggest that the MEP pathway is the main biosynthesis route for producing scent monoterpenes. To our knowledge, this is the first report describing the candidate pathway and the key enzyme for floral scent production in thermogenic plants.


Assuntos
Arum/genética , Flores/genética , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica de Plantas , Arum/metabolismo , Vias Biossintéticas/genética , Metabolismo Energético/genética , Flores/química , Flores/metabolismo , Ontologia Genética , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Odorantes/análise , Oxirredutases/genética , Oxirredutases/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Temperatura , Terpenos/metabolismo , Transferases/genética , Transferases/metabolismo
14.
Plant Cell Environ ; 38(4): 827-37, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25256124

RESUMO

Thermogenic flowers produce heat by intense respiration, and the rates of O2 consumption (Mo2) in some species can exceed those of all other tissues of plants and most animals. By exposing intact flowers to a range of O2 pressures (Po2) and measuring Mo2, we demonstrate that the highest respiration rates exceed the capacity of the O2 diffusive pathway and become diffusion limited in atmospheric air. The male florets on the inflorescence of Arum concinnatum have the highest known mass-specific Mo2 and can be severely diffusion limited. Intact spadices of Japanese skunk cabbage Symplocarpus renifolius are diffusion limited in air only when Mo2 is maximal, but not at lower levels. True flowers of the sacred lotus Nelumbo nucifera and the appendix of Arum concinnatum are never diffusion limited in air. Mo2 - Po2 curves are evaluated quantitatively with the 'Regulation Index', a new tool to measure dependence of Mo2 on ambient Po2 , as well as the conventional 'Critical Po2 '. The study also includes measurements of Po2 within thermogenic tissues with O2-sensitive fibre optics, and reveals that the diffusion pathway is complicated and that O2 can be provided not only from the surface of the tissues but also from the pith of the flower's peduncle.


Assuntos
Araceae/fisiologia , Arum/fisiologia , Flores/fisiologia , Nelumbo/fisiologia , Oxigênio/metabolismo , Transpiração Vegetal/fisiologia , Respiração Celular , Difusão , Temperatura Alta , Inflorescência/fisiologia , Oxigênio/análise , Análise de Regressão , Termogênese/fisiologia
15.
Nat Prod Res ; 29(17): 1678-83, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25520041

RESUMO

Arum dioscoridis, locally called 'Gavur pancari', is a wild plant the leaves of which have been used as vegetable and for preparing special soup which has a sour taste. This study was set up to determine in vitro antioxidant activities and total phenolic and flavonoid contents of different extracts of A. dioscoridis. Free radical scavenging activity was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing activity with different concentrations of ethanol, methanol, acetone and water extracts of the plant leaves. Total phenolic and flavonoid contents were widely variable depending on solvents. Ethanol and methanol extractions of the plant material showed better performances with respect to both phenolic and flavonoid contents, respectively. The highest phenolic and flavonoid contents of ethanol and methanol extracts were 100.890 mg/g GAE and 72.643 mg/g QE, respectively. The lower DPPH scavenging and ferric reducing activities were determined in comparison with previous reports and standard synthetic chemicals.


Assuntos
Arum/química , Sequestradores de Radicais Livres/química , Extratos Vegetais/química , Polifenóis/química , Compostos de Bifenilo , Flavonoides/química , Oxirredução , Picratos , Folhas de Planta/química
16.
Naturwissenschaften ; 101(8): 623-35, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24925357

RESUMO

Staining and histochemistry of volatile organic compounds (VOCs) were performed at different inflorescence developmental stages on nine aroid species; one temperate, Arum italicum and eight tropical from the genera Caladium, Dieffenbachia and Philodendron. Moreover, a qualitative and quantitative analysis of VOCs constituting the scent of A. italicum, depending on the stage of development of inflorescences was also conducted. In all nine species, vesicles were observed in the conical cells of either the appendix or the stamens (thecae) and the staminodes. VOCs were localised in intracellular vesicles from the early stages of inflorescence development until their release during receptivity of gynoecium. This localisation was observed by the increase of both number and diameter of the vesicles during 1 week before receptivity. Afterwards, vesicles were fewer and smaller but rarely absent. In A. italicum, staining and gas chromatography analyses confirmed that the vesicles contained terpenes. The quantitatively most important ones were the sesquiterpenes, but monoterpenes were not negligible. Indeed, the quantities of terpenes matched the vesicles' size evolution during 1 week. Furthermore, VOCs from different biosynthetic pathways (sesquiterpenes and alkanes) were at their maximum quantity 2 days before gynoecium receptivity (sesquiterpenes and alkanes) or during receptivity (isobutylamine, monoterpenes, skatole and p-cresol). VOCs seemed to be emitted during gynoecium receptivity and/or during thermogenesis, and FADs are accumulated after thermogenesis in the spadix. These complex dynamics of the different VOCs could indicate specialisation of some VOCs and cell machinery to attract pollinators on the one hand and to repulse/protect against phytophagous organisms and pathogens after pollination on the other hand.


Assuntos
Araceae/química , Arum/química , Polinização , Compostos Orgânicos Voláteis/análise , Araceae/crescimento & desenvolvimento , Arum/crescimento & desenvolvimento , Cromatografia Gasosa , Folhas de Planta/química , Terpenos/análise
17.
Appl Biochem Biotechnol ; 170(5): 1229-40, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23653140

RESUMO

Alternative oxidase (AOX) is a nonproton motive quinol-oxygen oxidoreductase which is a component of the mitochondrial respiratory chain in higher plants. In this study, we have characterized the catalytic activity and regulatory behaviors of Arum concinnatum AOX isoforms, namely AcoAOX1a and AcoAOX1b, and their artificial mutants in HeLa cells. We demonstrated that substitution of the motif-like sequence ENV on the C-terminal half of AcoAOX1a for QDT diminishes its activity and proposed that the innate inactivity of AcoAOX1b in HeLa cells is, at least in part, attributable to its QDT motif. Furthermore, we show that introduction of F130L in the hydrophilic N-terminal extension of AcoAOX1a resulted in greater activity in the presence of pyruvate. This result indicates that functional significance of the N-terminal extension is not particular to the conventional regulatory cysteine. On the basis of these findings, we discuss new insights into the structural integrity of AOX in HeLa cells and the applicability of mammalian cells for functional analysis of this enzyme.


Assuntos
Arum/química , Arum/fisiologia , Proteínas Mitocondriais/química , Proteínas Mitocondriais/metabolismo , Oxirredutases/química , Oxirredutases/metabolismo , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Engenharia de Proteínas/métodos , Motivos de Aminoácidos , Substituição de Aminoácidos , Catálise , Ativação Enzimática , Células HeLa , Humanos , Proteínas Mitocondriais/genética , Oxirredutases/genética , Proteínas de Plantas/genética , Relação Estrutura-Atividade
18.
Plant Physiol Biochem ; 63: 140-50, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23262182

RESUMO

The low photosynthetic activity of fleshy green fruits is currently attributed to their special anatomy rather than to a down-regulation of photosystem II (PSII). However, it is unclear whether the organization of PSII, which is highly conserved in leaves, is also shared by non-foliar structures, such as fleshy fruits. To obtain new information on this aspect, the photosynthetic activity and the organization of PSII were investigated in the berry of Arum italicum Miller during maturation (ivory to green) and early ripening (green to yellow). The berry developed an "internal CO(2) recycling" photosynthesis; gross photosynthesis at the green stage was 25% of the leaf lamina. SDS-PAGE, BN-PAGE and 77 K spectrofluorimetry showed that the thylakoid membrane accumulated a very high amount of free LHCII trimers and only few PSII and PSI complexes. The pattern of PSII forms was similar to that of the lamina (monomers, dimers, LHCII-PSII supercomplexes), but increase in CP43-less PSII cores and low F695/F680 fluorescence ratio at room temperature indicated that PSII was less stable than in the leaf lamina. Beside effective PSII photoprotection, we propose that LHCII serves as a temporary storage of chlorophylls to provide a visual signal that fruit is not mature for seed dispersal. We conclude that the low photosynthetic activity of A. italicum berry depends on the scantiness of reaction centres and the reduced functionality of PSII.


Assuntos
Arum/metabolismo , Frutas/metabolismo , Fotossíntese/fisiologia , Complexo de Proteína do Fotossistema II/metabolismo , Clorofila/metabolismo , Eletroforese em Gel de Poliacrilamida
19.
Br Dent J ; 213(12): 589, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23257789
20.
Biochem J ; 445(2): 237-46, 2012 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-22512685

RESUMO

Symplocarpus renifolius and Arum maculatum are known to produce significant heat during the course of their floral development, but they use different regulatory mechanisms, i.e. homoeothermic compared with transient thermogenesis. To further clarify the molecular basis of species-specific thermogenesis in plants, in the present study we have analysed the native structures and expression patterns of the mitochondrial respiratory components in S. renifolius and A. maculatum. Our comparative analysis using Blue native PAGE combined with nano LC (liquid chromatography)-MS/MS (tandem MS) has revealed that the constituents of the respiratory complexes in both plants were basically similar, but that several mitochondrial components appeared to be differently expressed in their thermogenic organs. Namely, complex II in S. renifolius was detected as a 340 kDa product, suggesting an oligomeric or supramolecular structure in vivo. Moreover, the expression of an external NAD(P)H dehydrogenase was found to be higher in A. maculatum than in S. renifolius, whereas an internal NAD(P)H dehydrogenase was expressed at a similar level in both species. Alternative oxidase was detected as smear-like signals that were elongated on the first dimension with a peak at around 200 kDa in both species. The significance and implication of these data are discussed in terms of thermoregulation in plants.


Assuntos
Araceae/metabolismo , Arum/metabolismo , Mitocôndrias/metabolismo , Proteínas Mitocondriais/metabolismo , Oxirredutases/metabolismo , Proteínas de Plantas/metabolismo , Termogênese , Sequência de Aminoácidos , Araceae/genética , Arum/genética , Western Blotting , Transporte de Elétrons , Eletroforese em Gel Bidimensional , Flores , Mitocôndrias/genética , Proteínas Mitocondriais/genética , Dados de Sequência Molecular , NADPH Desidrogenase/genética , NADPH Desidrogenase/metabolismo , Oxirredutases/genética , Filogenia , Proteínas de Plantas/genética , Homologia de Sequência de Aminoácidos , Espectrometria de Massas em Tandem
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