RESUMEN
The interest expressed by the agriculture in the category of innovative biostimulants is due to the intensive search for natural preparations. Our study is the first ever to report a complex approach to the use of allelopathic extracts from Levisticum officinale Koch. roots in soybean cultivation, includes analyses of morphological observations, and analyses of biochemical indicators. Hot method of aqueous extraction was applied. The extracts were administered via foliar application and soil treatment. Lovage extracts had high contents of polyphenolic compounds and rich micro- and macroelemental composition. The infusions did not contain gibberellic acid and indole-3-acetic acid but the abscisic acid and saccharose, glucose, and fructose were found. The extracts modified soybean plant physiology, as manifested by changes in biometric traits. Plants responded positively by increased yield. Seeds from the treated plants had higher contents of micro- and macroelements, as well as total concentrations of lipids (with a slight decrease in protein content). In addition, they featured changes in their amino acid profile and fatty acid composition. The application of allelopathic biostimulant caused increased concentrations of isoflavones and saponins. The natural biostimulants from Levisticum officinale may become a valuable tool in the sustainable agriculture.
Asunto(s)
Glycine max/química , Levisticum/efectos de los fármacos , Extractos Vegetales/farmacología , Raíces de Plantas/química , Ácido Abscísico/química , Ácido Abscísico/farmacología , Fabaceae/efectos de los fármacos , Fabaceae/crecimiento & desarrollo , Giberelinas/química , Glucosa/química , Glucosa/farmacología , Levisticum/química , Levisticum/crecimiento & desarrollo , Feromonas/química , Feromonas/farmacología , Extractos Vegetales/química , Semillas/química , Sacarosa/química , Sacarosa/farmacología , Agua/químicaRESUMEN
Tea (Camellia sinensis) is one of the most important cash crops in the world. Theanine, as an important amino acid component in tea, is a key quality index for excellent tea quality and high economic value. People increase theanine accumulation in tea mainly through the application of nitrogen fertilizer, shading and pruning. However, these methods are not effective. In this study, we treated tea buds with a 100 µM solution of GA3 containing 1 tween-20, investigated the effects of GA3 on theanine accumulation, bud yield, chlorophyll fluorescence parameters and expression level of theanine biosynthesis pathway genes in tea plant by qPCR, LC-MS/MS etc. Results showed that change trends of theanine and GA3 was extremely positively correlated with each other. Exogenous GA3 upregulated the expression level of theanine biosynthesis pathway genes, caused an increase of theanine content (mg·g-1) by 27% in tea leaves compared with Mock, and accelerated the germination of buds and elongation of shoots, which lead to a significant increase of tea yield by 56% (w/w). Moreover, the decrease of chlorophyll contents, photochemical quenching coefficient (qP) and relative electron transport rate (rETR) under GA3 treatment suggested that GA3 reduced photosynthesis in the tender tea leaves, indicating that the decline of carbon assimilation in tea plants was conducive to the nitrogen metabolism, and it was beneficial to the accumulation of theanine. This study provided a new technical and theoretical support for the precise control of tea quality components and phenophase.
Asunto(s)
Camellia sinensis/crecimiento & desarrollo , Camellia sinensis/metabolismo , Giberelinas/farmacología , Hojas de la Planta/metabolismo , Té/metabolismo , Aminoácidos/química , Clorofila/química , Cromatografía Liquida , Giberelinas/química , Glutamatos/química , Nitrógeno/metabolismo , Fotosíntesis , Proteínas de Plantas/genética , Brotes de la Planta , Reacción en Cadena de la Polimerasa , Espectrometría de Masas en TándemRESUMEN
As a widely used plant growth regulator, the gibberellic acid (GA3) residue in tea has potential risk for human health. Herein, the degradation of GA3 and its conversion into main metabolites were investigated during tea planting, manufacturing, and brewing using ultrahigh-performance liquid chromatography tandem mass spectrometry. The metabolite iso-GA3 was first discovered during the tea production chain and identified using Q-Exactive Orbitrap mass spectrometry. GA3 dissipated following first-order kinetics in tea shoots with half-lives ranging from 2.46 to 2.74 days. It was degraded into iso-GA3 in tea shoots, which had a longer residual period than GA3. Meanwhile, external application of GA3 could increase the proportion of growth-promoting endogenous phytohormones and lead to rapid growth of tea plants. During tea manufacturing, iso-GA3 was quickly and massively converted from GA3. Fixing (heat at 220-230 °C) played an important role in the dissipation of GA3 and iso-GA3 during green tea manufacturing, but there were high residues of iso-GA3 in black tea. High transfer rates (77.3 to 94.5%) of GA3 and iso-GA3 were observed during tea brewing. These results could provide a practical reference for food safety in tea and other agricultural products and the guidance for scientific application of GA3 in tea planting.
Asunto(s)
Camellia sinensis/metabolismo , Giberelinas/química , Giberelinas/metabolismo , Reguladores del Crecimiento de las Plantas/química , Reguladores del Crecimiento de las Plantas/metabolismo , Camellia sinensis/química , Camellia sinensis/crecimiento & desarrollo , Culinaria , Residuos de Medicamentos/química , Residuos de Medicamentos/metabolismo , Inocuidad de los Alimentos , Calor , Humanos , Espectrometría de Masas , Hojas de la Planta/química , Hojas de la Planta/crecimiento & desarrollo , Hojas de la Planta/metabolismo , Té/químicaRESUMEN
The presence in cypress pollen of an important allergen, belonging to the gibberellin-regulated protein (GRP) family, has been suggested for many years. However, it has never been isolated and sometimes the homologous peach allergen, Pru p 7, has been used as a surrogate to perform immunological investigations. The aim of this study has been the isolation and molecular characterization of the GRP contained in the Cupressus sempervirens pollen. This protein, named Cypmaclein, has been purified from the natural source using conventional biochemical methods consisting in different chromatographic separations. Cypmaclein has been identified by direct protein sequencing of the N-terminal region and of internal fragments of the molecule. In SDS-PAGE, its apparent molecular mass is slightly higher than that of Pru p 7. Nevertheless, the mass spectrometry experiments reveal that the exact molecular mass of Cypmaclein (6821.88â¯Da) is very close to that of Pru p 7 (6909.90â¯Da). Two regions of Cypmaclein have been sequenced providing 50% of its primary structure. A high overall sequence identity of Cypmaclein with all the analyzed GRP has been observed, although in the N-terminal region the high identity is limited to the homolog of Cryptomeria japonica. In circular dichroism experiments Cypmaclein produced a spectrum overlapping that of Pru p 7. However, the comparative analysis of Cypmaclein, Pru p 7 and Pun g 7 IgE reactivity revealed a behavior that was not completely overlapping, thus suggesting that the IgE epitopes are only partially shared. In single point highest inhibition achievable assays performed with the FABER test, Cypmaclein efficiently competed with the allergenic peach and pomegranate GRP in the binding of specific IgE of patients sensitized to Pru p 7. In conclusion, the natural cypress pollen GRP has been isolated for the first time, its structural features have been investigated and its cross-reactivity with Pru p 7 and Pun g 7 has been demonstrated. This protein is now available for further investigations aimed at understanding its clinical relevance in the allergy to cypress pollen. In addition, the prevalence of sensitization directly to Cypmaclein, and not limited to the homologs, can be defined.
Asunto(s)
Cupressus/química , Cupressus/inmunología , Giberelinas/química , Giberelinas/inmunología , Inmunoglobulina E/inmunología , Proteínas de Plantas/química , Proteínas de Plantas/inmunología , Adolescente , Adulto , Secuencia de Aminoácidos , Antígenos de Plantas/química , Antígenos de Plantas/inmunología , Niño , Reacciones Cruzadas/inmunología , Epítopos/química , Epítopos/inmunología , Femenino , Humanos , Masculino , Polen/química , Polen/inmunología , Rinitis Alérgica Estacional/inmunología , Adulto JovenRESUMEN
Light is the most important physical factor in growth and development of plants. Light intensity is directly proportional to the growth and accumulation of natural antioxidants during in vitro cultures of various medicinal plants. The present research study was designed to determine the effect of different light intensities i.e. normal light (2000-2500â¯lx), diffused light (500-1000â¯lx) and complete dark (0â¯lx) on callus growth dynamics and production of natural antioxidants in olive cult. Arbosana. Highest callus induction frequency (50%) was observed in the stem explants pre-treated with silver nanoparticles suspension (AgNPs: 50â¯ppm) and cultured on MS media supplemented with combination of 6-Benzylaminopurine (BAP: 2â¯mg/l), Gibberellic acid (GA3: 1.5â¯mg/l) plus Naphthalene acetic acid (NAA: 0.5â¯mg/l). Maximum callus biomass (FWâ¯=â¯1414â¯mg/l) was recorded when the cultured explants were incubated initially for seven days in complete darkness, followed by transference to diffused light for one week and then finally placed under normal light in total fifty six days culture period. Moreover, phytochemical analysis of the callus cultures showed significantly higher activities of antioxidant enzymes i.e. SOD, POD, CAT and APx (2.45, 2.96, 2.57 and 1.67â¯U/mg. protein) in the callus cultures grown under dark condition as compared with other light treatments. For non-enzymatic antioxidant potential, maximum activity of TPC, TFC, PAL and DPPH (2.42â¯mg GAE/g, 1.50â¯mg QAE/g, 3.95â¯U/mg and 75%) were recorded in the calli raised in vitro under diffused light. This is the first report on the production of natural antioxidants in response to different light intensities in callus cultures of Olea europaea. Future studies should focus on large scale production of callus cultures in order to yield maximum biomass from this high valued plant.
Asunto(s)
Antioxidantes/metabolismo , Biomasa , Luz , Olea/efectos de la radiación , Antioxidantes/química , Compuestos de Bencilo/química , Catalasa/metabolismo , Giberelinas/química , Nanopartículas del Metal/química , Olea/citología , Olea/metabolismo , Células Vegetales/metabolismo , Proteínas de Plantas/metabolismo , Purinas/química , Plata/química , Superóxido Dismutasa/metabolismoRESUMEN
BACKGROUND: To date, three orange allergens have been reported. However, it is still unclear whether gibberellin-regulated proteins (GRPs), identified as new allergens in other fruit allergies, are also involved in orange allergy. OBJECTIVE: To investigate the allergenicity of orange GRP and to determine the clinical characteristics of patients with orange allergy who are sensitized to orange GRP. METHODS: We enrolled 14 patients (four men, 10 women, mean age: 29.6 years) who were diagnosed with orange allergy based on relevant clinical history, positive skin test, and/or positive challenge test. Orange GRP (molecular weight: 6941.6 Da) was purified by ion-exchange column chromatography. To test for orange GRP-specific IgE, we performed ELISA, basophil activation tests, and skin prick tests. Cross-reactivity of orange GRP with native peach allergen nPru p 7 and Japanese apricot nPru m 7 was analysed by ELISA inhibition assays. IgE specific for orange, grapefruit, and peach allergens rPru p 1, rPru p 3, and rPru p 4 was measured using ImmunoCAP. RESULTS: Twelve of the 14 patients (85.7%) were positive for orange GRP allergy in at least one test: 71.4% (10/14) were positive by ELISA, 50% (3/6) were positive in the basophil activation test, and 100% (4/4) were positive in the skin prick test. ELISA inhibition assays revealed cross-reactivity of orange GRP with both nPru p 7 and nPru m 7. The patients showed variable positivity for specific IgE against orange, grapefruit, rPru p 1, rPru p 3, and rPru p 4 (57.1%, 71.4%, 7.1%, 0%, and 21.4%, respectively). The most frequent symptoms of orange GRP allergy were facial swelling and oropharyngeal symptoms. CONCLUSIONS AND CLINICAL RELEVANCE: Orange GRP may be involved in orange allergy and may be a cross-reactive allergen between citrus fruits and the Rosaceae family of fruits.
Asunto(s)
Alérgenos/inmunología , Antígenos de Plantas/inmunología , Citrus sinensis/efectos adversos , Hipersensibilidad a los Alimentos/inmunología , Giberelinas/inmunología , Adolescente , Adulto , Alérgenos/química , Secuencia de Aminoácidos , Anticuerpos/inmunología , Especificidad de Anticuerpos/inmunología , Antígenos de Plantas/química , Niño , Reacciones Cruzadas/inmunología , Ensayo de Inmunoadsorción Enzimática , Femenino , Hipersensibilidad a los Alimentos/diagnóstico , Giberelinas/química , Humanos , Inmunoglobulina E/inmunología , Masculino , Persona de Mediana Edad , Extractos Vegetales/inmunología , Pruebas Cutáneas , Adulto JovenRESUMEN
BACKGROUND: Phytic acid as a phosphorus storage vault provides phosphorus for plant development. It is an anti-nutritional factor for humans and some animals. However, its degradation products lower inositol phosphates have positive effects on human health. In this study, the effect of gibberellic acid (GA) on phytic acid degradation under calcium lactate (Ca) existence was investigated. RESULTS: The results showed that Ca + GA treatment promoted the growth status, hormone metabolism and phytic acid degradation in germinating soybean. At the same time, the availability of phosphorus, the activity of phytic acid degradation-associated enzyme and phosphoinositide-specific phospholipase C (PI-PLC) increased. However, the relative genes expression of phytic acid degradation-associated enzymes did not vary in accordance with their enzymes activity. CONCLUSION: The results revealed that GA could mediate the transport and function of calcium and a series of physiological and biochemical changes to regulate phytic acid degradation of soybean sprouts. © 2017 Society of Chemical Industry.
Asunto(s)
Compuestos de Calcio/farmacología , Germinación/fisiología , Giberelinas/química , Glycine max/crecimiento & desarrollo , Lactatos/farmacología , Ácido Fítico/metabolismo , 6-Fitasa/metabolismo , Fosfatasa Ácida/metabolismo , Regulación Enzimológica de la Expresión Génica/efectos de los fármacos , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Fosfolípidos/química , Fosfolípidos/metabolismo , Fósforo/metabolismo , Ácido Fítico/química , Semillas/efectos de los fármacos , Semillas/crecimiento & desarrollo , Glycine max/efectos de los fármacosAsunto(s)
Alérgenos/inmunología , Antígenos de Plantas/inmunología , Hipersensibilidad a los Alimentos/inmunología , Polen/inmunología , Alérgenos/química , Secuencia de Aminoácidos , Antígenos de Plantas/química , Reacciones Cruzadas/inmunología , Hipersensibilidad a los Alimentos/diagnóstico , Giberelinas/química , Giberelinas/inmunología , Humanos , Inmunoglobulina E/inmunología , Espectrometría de Masas , Proteínas de Plantas/química , Proteínas de Plantas/inmunología , Polen/químicaRESUMEN
BACKGROUND: GSL1 and GSL2, Gibberellin Stimulated-Like proteins (also known as Snakin-1 and Snakin-2), are cysteine-rich peptides from potato (Solanum tuberosum L.) with antimicrobial properties. Similar peptides in other species have been implicated in diverse biological processes and are hypothesised to play a role in several aspects of plant development, plant responses to biotic or abiotic stress through their participation in hormone crosstalk, and redox homeostasis. To help resolve the biological roles of GSL1 and GSL2 peptides we have undertaken an in depth analysis of the structure and expression of these genes in potato. RESULTS: We have characterised the full length genes for both GSL1 (chromosome 4) and GSL2 (chromosome 1) from diploid and tetraploid potato using the reference genome sequence of potato, coupled with further next generation sequencing of four highly heterozygous tetraploid cultivars. The frequency of SNPs in GSL1 and GSL2 were very low with only one SNP every 67 and 53 nucleotides in exon regions of GSL1 and GSL2, respectively. Analysis of comprehensive RNA-seq data substantiated the role of specific promoter motifs in transcriptional control of gene expression. Expression analysis based on the frequency of next generation sequence reads established that GSL2 was expressed at a higher level than GSL1 in 30 out of 32 tissue and treatment libraries. Furthermore, both the GSL1 and GSL2 genes exhibited constitutive expression that was not up regulated in response to biotic or abiotic stresses, hormone treatments or wounding. Potato transformation with antisense knock-down expression cassettes failed to recover viable plants. CONCLUSIONS: The potato GSL1 and GSL2 genes are very highly conserved suggesting they contribute to an important biological function. The known antimicrobial activity of the GSL proteins, coupled with the FPKM analysis from RNA-seq data, implies that both genes contribute to the constitutive defence barriers in potatoes. The lethality of antisense knock-down expression of GSL1 and GSL2, coupled with the rare incidence of SNPs in these genes, suggests an essential role for this gene family. These features are consistent with the GSL protein family playing a role in several aspects of plant development in addition to plant defence against biotic stresses.
Asunto(s)
Genes de Plantas , Giberelinas/genética , Proteínas de Plantas/genética , Solanum tuberosum/genética , Alelos , Cromosomas de las Plantas , Biología Computacional , Secuencia Conservada/genética , Diploidia , Regulación de la Expresión Génica de las Plantas , Giberelinas/química , Giberelinas/metabolismo , Secuenciación de Nucleótidos de Alto Rendimiento , Oligonucleótidos Antisentido/metabolismo , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Polimorfismo de Nucleótido Simple , Regiones Promotoras Genéticas , Solanum tuberosum/metabolismo , TetraploidíaRESUMEN
Gibberelic acid fermentation using extractive methods was carried out in the presence of corn oil and Alamine 336. Gibberella fujikuroi fungus (NRRL 2278) was used to produce gibberellic acid. Oleyl alcohol was a diluting agent for Alamine 336. The effects of oleyl alcohol (100%, v/v), corn oil (5-25%, v/v), the concentration of Alamine 336 in oleyl alcohol, and feeding air were examined in this study. According to the results, oleyl alcohol was not effective on the production. On the other hand, oleyl alcohol solutions containing 15-30% (v/v) Alamine 336 showed effects as a toxic substance. In order to reduce solvent toxicity, corn oil was used. Addition of corn oil increased the concentration of gibberellic acid 1.3-fold compared to the control. Then the effects of immobilization and co-immobilization on extractive gibberelic acid fermentation were investigated. The highest total gibberellic acid concentration of 158.9 mg/L was produced with immobilized cells and feeding air by using extractive fermentation. The yield of gibberellic acid increased about 2.6-fold compared with the shake-flask fermentation (60.5 mg/L) without organic solutions.
Asunto(s)
Aceite de Maíz/farmacología , Alcoholes Grasos/farmacología , Gibberella/crecimiento & desarrollo , Giberelinas/biosíntesis , Células Inmovilizadas/metabolismo , Gibberella/química , Gibberella/metabolismo , Giberelinas/química , Giberelinas/aislamiento & purificaciónRESUMEN
The residues of gibberellic acid (GA(3)) in tea shoots, made tea, and tea infusion were determined by ultra-performance liquid chromatography tandem mass (UPLC-MS/MS) to study its degradation pattern during tea planting, processing, and brewing. The dissipation rate of GA(3) was described using first-order kinetics. Its half-life ranged from 1.67 to 2.01 days in tea shoots. Degradation and concentration during green tea processing had equally important functions on GA(3) residues in product intermediates and made tea. Except for water content, little GA(3) residue difference was found in tea shoots and made tea. GA(3) dissipated rapidly in the baking stage during processing. The transfer coefficient of GA(3) residues from made tea to infusion was from 26.23% to 54.55%. GA(3) extraction efficiency varied with different infusion times and concentrations of GA(3) in made tea. This research revealed that GA(3) may be safe when applied in tea gardens at suitable doses and picking intervals.
Asunto(s)
Camellia sinensis/química , Giberelinas/química , Extractos Vegetales/química , Té/química , Manipulación de Alimentos , CinéticaRESUMEN
The traditional Chinese medicinal plant, Isodon L., is remarkably rich in pharmacologically active ent-kaurane diterpenoids of diverse carbon skeletons. In an effort to create a resource for gene discovery and elucidate the biosynthesis of Isodonent-kaurane diterpenoids, three cDNAs (named IeCPS1, IeCPS2 and IeCPS2a) were isolated putatively encoding copalyl diphosphate synthases from Isodoneriocalyx leaves. Recombinant proteins of IeCPS1 and IeCPS2 were expressed, respectively, in Escherichia coli, and were shown to specifically convert geranylgeranyl diphosphate to copalyl diphosphate as demonstrated by GC-MS analyses. Based on tissue-specific expression and metabolic localization studies, the IeCPS2 transcripts were detected in young and mature leaves where the dominant ent-kaurane diterpenoid maoecrystal B accumulates, whereas no detectable expression of IeCPS2 was observed in germinating seeds where the gibberellin biosynthetic pathway is usually active. In addition, no evidence for maoecrystal B was found in germinating seeds. On the other hand, IeCPS1 transcripts significantly accumulated in germinating seeds as well as in leaves. The biochemical and molecular genetic evidence thus indicated that IeCPS2 is a copalyl diphosphate synthase potentially involved in the biosynthesis of Isodon diterpenoids in leaves, while IeCPS1 is more probably relevant to gibberellin formation and may, in addition, participate in Isodonent-kaurane diterpenoid production.
Asunto(s)
Transferasas Alquil y Aril/química , Diterpenos de Tipo Kaurano/biosíntesis , Giberelinas/química , Isodon/química , Proteínas de Plantas/química , Transferasas Alquil y Aril/genética , Transferasas Alquil y Aril/aislamiento & purificación , Secuencia de Aminoácidos , Clonación Molecular , ADN Complementario/genética , Diterpenos de Tipo Kaurano/química , Activación Enzimática , Escherichia coli/química , Escherichia coli/genética , Cromatografía de Gases y Espectrometría de Masas , Germinación , Isodon/enzimología , Isodon/genética , Medicina Tradicional China , Datos de Secuencia Molecular , Organofosfatos/química , Filogenia , Hojas de la Planta/química , Hojas de la Planta/enzimología , Hojas de la Planta/genética , Proteínas de Plantas/genética , Proteínas de Plantas/aislamiento & purificación , Fosfatos de Poliisoprenilo/química , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Semillas/química , Semillas/enzimología , Especificidad por SustratoRESUMEN
Stamen development is governed by a conserved genetic pathway, within which the role of hormones has been the subject of considerable recent research. Our understanding of the involvement of gibberellin (GA) signalling in this developmental process is further advanced than for the other phytohormones, and here we review recent experimental results in rice (Oryza sativa) and Arabidopsis (Arabidopsis thaliana) that have provided insight into the timing and mechanisms of GA regulation of stamen development, identifying the tapetum and developing pollen as major targets. GA signalling governs both tapetum secretory functions and entry into programmed cell death via the GAMYB class of transcription factor, the targets of which integrate with the established genetic framework for the regulation of tapetum function at multiple hierarchical levels.
Asunto(s)
Arabidopsis/crecimiento & desarrollo , Giberelinas/farmacología , Oryza/crecimiento & desarrollo , Reguladores del Crecimiento de las Plantas/farmacología , Arabidopsis/anatomía & histología , Arabidopsis/efectos de los fármacos , Fertilidad , Flores/efectos de los fármacos , Flores/crecimiento & desarrollo , Regulación de la Expresión Génica de las Plantas , Genes Homeobox , Giberelinas/biosíntesis , Giberelinas/química , Oryza/anatomía & histología , Oryza/efectos de los fármacos , Polen/efectos de los fármacos , Polen/crecimiento & desarrollo , Transducción de SeñalRESUMEN
Gibberellins are a group of naturally occurring diterpenoid based phytohormones that play a vital role in plant growth and development. In this work, we have studied the self-assembly of gibberellic acid, a phytohormone, which belongs to the family of gibberellins, and designed amide derivatives of gibberellic acid (GA(3)) for the facile, green synthesis of gold nanoparticles. It was found that the derivatives self-assembled into nanofibers and nanoribbons in aqueous solutions at varying pH. Further, upon incubation with tetrachloroaurate, the self-assembled GA(3)-amide derivatives efficiently nucleated and formed gold nanoparticles when heated to 60 degrees C. Energy dispersive x-ray spectroscopy, transmission electron microscopy and scanning electron microscopy analyses revealed that uniform coatings of gold nanoparticles in the 10-20 nm range were obtained at low pH on the nanowire surfaces without the assistance of additional reducing agents. This simple method for the development of morphology controlled gold nanoparticles using a plant hormone derivative opens doors for a new class of plant biomaterials which can efficiently yield gold nanoparticles in an environmentally friendly manner. The gold encrusted nanowires formed using biomimetic methods may lead on to the formation of conductive nanowires, which may be useful for a wide range of applications such as in optoelectronics and sensors. Further, the spontaneous formation of highly organized nanostructures obtained from plant phytohormone derivatives such as gibberellic acid is of particular interest as it might help in further understanding the supramolecular assembly mechanism of more highly organized biological structures.
Asunto(s)
Cristalización/métodos , Giberelinas/química , Oro/química , Nanoestructuras/química , Nanoestructuras/ultraestructura , Nanotecnología/métodos , Extractos Vegetales/química , Amidas/química , Sustancias Macromoleculares/química , Ensayo de Materiales , Conformación Molecular , Tamaño de la Partícula , Propiedades de SuperficieRESUMEN
A major catabolic pathway for the gibberellins (GAs) is initiated by 2beta-hydroxylation, a reaction catalyzed by 2-oxoglutarate-dependent dioxygenases. To isolate a GA 2beta-hydroxylase cDNA clone we used functional screening of a cDNA library from developing cotyledons of runner bean (Phaseolus coccineus L.) with a highly sensitive tritium-release assay for enzyme activity. The encoded protein, obtained by heterologous expression in Escherichia coli, converted GA9 to GA51 (2beta-hydroxyGA9) and GA51-catabolite, the latter produced from GA51 by further oxidation at C-2. The enzyme thus is multifunctional and is best described as a GA 2-oxidase. The recombinant enzyme also 2beta-hydroxylated other C19-GAs, although only GA9 and GA4 were converted to the corresponding catabolites. Three related cDNAs, corresponding to gene sequences present in Arabidopsis thaliana databases, also encoded functional GA 2-oxidases. Transcripts for two of the Arabidopsis genes were abundant in upper stems, flowers, and siliques, but the third transcript was not detected by Northern analysis. Transcript abundance for the two most highly expressed genes was lower in apices of the GA-deficient ga1-2 mutant of Arabidopsis than in wild-type plants and increased after treatment of the mutant with GA3. This up-regulation of GA 2-oxidase gene expression by GA contrasts GA-induced down-regulation of genes encoding the biosynthetic enzymes GA 20-oxidase and GA 3beta-hydroxylase. These mechanisms would serve to maintain the concentrations of biologically active GAs in plant tissues.
Asunto(s)
Fabaceae/enzimología , Giberelinas/metabolismo , Oxigenasas de Función Mixta/metabolismo , Plantas Medicinales , Secuencia de Aminoácidos , Secuencia de Bases , Biotransformación , Clonación Molecular , Cartilla de ADN , Fabaceae/genética , Giberelinas/química , Oxigenasas de Función Mixta/química , Oxigenasas de Función Mixta/genética , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Alineación de Secuencia , Homología de Secuencia de AminoácidoRESUMEN
The identity of a new gibberellin (GA) in spinach and oil palm sap has been confirmed as 2 beta-hydroxy-GA12 (GA110) by comparisons of GC-mass spectral data obtained for the trimethylsilyl ether methyl ester derivatives with those of a synthetic sample prepared by means of a 24 step sequence from gibberellic acid; 2 beta-hydroxy-GA24 was also prepared. Experimental details for the latter part of the syntheses are described.