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1.
Nat Prod Res ; : 1-5, 2021 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-34583599

RESUMO

This study focuses on the identification of major anthocyanin following its temporal accumulation in colour changing flowers of Combretum indicum (L.) DeFilipps (syn. Quisqualis indica L.). Separation and identification of pigments governing changes in floral colour were performed using HPLC-DAD. Comparison of chromatographic runs with retention time and UV-Vis spectra of authentic standards determined cyanidin 3-O-glucoside as the major anthocyanin accumulating in the petals. Acid hydrolysis of anthocyanin extracts further confirmed cyanidin as the major anthocyanidin in floral tissue. Light microscopic studies revealed gradual accumulation of pigments in the epidermal and hypodermal cell layers of petals. Antioxidant potentials of floral extracts in ethanol, methanol, water and ethyl acetate were determined by DPPH assay where methanolic extracts showed highest free-radical scavenging capacity, and petals of red stage showed maximum activity. Antioxidative potentials measured in terms of FRAP and ABTS also indicated similar results showing highest activity in the red stage.

2.
Plant Mol Biol ; 106(6): 533-554, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34263437

RESUMO

KEY MESSAGE: The role of central carbon metabolism in the synthesis and emission of scent volatiles in tuberose flowers was revealed through measurement of changes in transcripts and metabolites levels. Tuberose or Agave amica (Medikus) Thiede & Govaerts is a widely cultivated ornamental plant in several subtropical countries. Little is known about metabolite networking involved in biosynthesis of specialized metabolites utilizing primary metabolites. In this study, metabolite profiling and gene expression analyses were carried out from six stages of maturation throughout floral lifespan. Multivariate analysis indicated distinction between early and late maturation stages. Further, the roles of sugars viz. sucrose, glucose and fructose in synthesis, glycosylation and emission of floral scent volatiles were studied. Transcript levels of an ABC G family transporter (picked up from the floral transcriptome) was in synchronization with terpene volatiles emission during the anthesis stage. A diversion from phenylpropanoid/benzenoid to flavonoid metabolism was observed as flowers mature. Further, it was suggested that this metabolic shift could be mediated by isoforms of 4-Coumarate-CoA ligase along with Myb308 transcription factor. Maximum glycosylation of floral scent volatiles was shown to occur at the late mature stage when emission declined, facilitating both storage and export from the floral tissues. Thus, this study provides an insight into floral scent volatiles synthesis, storage and emission by measuring changes at transcripts and metabolites levels in tuberose throughout floral lifespan.


Assuntos
Agave/genética , Flores/genética , Regulação da Expressão Gênica de Plantas , Odorantes/análise , Transcriptoma , Compostos Orgânicos Voláteis/metabolismo , Agave/crescimento & desenvolvimento , Agave/metabolismo , Cromatografia Líquida de Alta Pressão/métodos , Flavonoides/análise , Flores/crescimento & desenvolvimento , Flores/metabolismo , Cromatografia Gasosa-Espectrometria de Massas/métodos , Perfilação da Expressão Gênica/métodos , Hidroxibenzoatos/análise , RNA-Seq/métodos
3.
Planta ; 253(1): 13, 2021 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-33389109

RESUMO

MAIN CONCLUSION: Three types of the glandular trichomes are developed on the flowers and leaves of Millingtonia hortensis. Morphology, cell ultrastructure and content of the volatile compounds are specific to each trichome type. The aim of this study was to characterize the structural and histochemical features of the glandular trichomes (GTs) of two types localized on the different flower parts and leaves in Millingtonia hortensis, as well as to identify the composition of the internal pool of metabolites. The peltate GTs are most common; they are founded on peduncle, calyx, ovary, and leaves. GTs consist of 12-24-cell disk-shaped head and a single-celled neck. The capitate GTs are located on corolla tube and have four to eight-cell head, single-celled neck and a wide multicellular stalk. A series of histochemical reactions and fluorescent microscopy revealed the various substances in the chemical composition of GTs. Acid polysaccharides are predominately identified in the capitate trichomes of the corolla tube and peltate trichomes of calyx, terpenes present in larger quantity in the trichomes of the corolla tube and ovary, whilst phenolic substances prevail in the trichomes of the calyx and ovary. GTs of each type are characterized by specific ultrastructural traits. Smooth endoplasmic reticulum (SER) and leucoplasts prevail in the peltate trichomes of peduncle, calyx and ovary; Golgi apparatus is the common organelle in the capitate trichomes of the corolla tube and peltate trichomes of calyx; the huge aggregates of the RER cisterns there are in cytoplasm of all leaf trichomes. Synthesized secretion accumulates in the subcuticular cavity of all GTs except the leaf peltate trichomes. In the trichomes of the leaves secretion is stored in the thick upper cell wall with the wide cutinized layer. For the first time content of the internal pool of metabolites from the flowers and leaves was identified by GC-MS. Seventeen compounds, including alcohols, fatty acid derivatives, monoterpenes, sesquiterpenes, and benzenoids were identified. 1-octen 3-ol, 3-carene, methyl salicylate, p-hydroxybenzeneethanol and 1-hydroxy-2,4-di-tertbutyl-benzene were the main compounds of the flower scent. We consider GTs of the reproductive organs in M. hortensis synthesizing acid polysaccharides and volatile compounds as secretory structures attracting of pollinators, whereas the leaf peltate trichomes accumulating predominately non-volatile phenols, protect young vegetative shoots against small herbivorous insects and pathogens.


Assuntos
Bignoniaceae , Flores , Folhas de Planta , Tricomas , Flores/química , Flores/ultraestrutura , Folhas de Planta/química , Folhas de Planta/ultraestrutura , Tricomas/química , Tricomas/ultraestrutura
4.
Nat Prod Res ; 35(1): 140-143, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31184502

RESUMO

The present study focuses on the emitted and endogenous scent profiles of Uvaria hamiltonii flowers. Among the 34 compounds identified, sesquiterpenoids were found to dominate the floral volatiles composition. Profiles from endogenous scent volatiles showed higher number of compounds than the emitted ones. The anthocyanin pigment responsible for the flower colour was also explored. It was found that a single anthocyanin compound, cyanidin-3-O-glucoside, was principally responsible for petal colour. Total phenolic content was evaluated and antioxidant capacities were studied with the help of DPPH, FRAP and ABTS assays. The total phenolic content and the antioxidant capacity were higher in methanolic extract as compared to aqueous, petroleum ether and ethyl acetate extracts of U. hamiltonii flowers.


Assuntos
Antocianinas/metabolismo , Flores/fisiologia , Uvaria/química , Uvaria/metabolismo , Compostos Orgânicos Voláteis/metabolismo , Antocianinas/análise , Antioxidantes/análise , Antioxidantes/química , Flores/química , Odorantes/análise , Fenóis/análise , Pigmentação , Extratos Vegetais/química , Compostos Orgânicos Voláteis/análise
5.
Microbiol Res ; 241: 126582, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32882536

RESUMO

Exploring the beneficial interactions between plant and endophytes could be an effective strategy in the implementation of sustainable agricultural practices to enhance crop productivity. In this study, we aimed to evaluate holistically the plant growth promoting (PGP) abilities rendered by seed-transmitted endophytic bacteria isolated from in vitro grown calli of two rice cultivars. Nine bacterial endophytes, designated as PB001-PB009, were isolated and identified at the genus level through 16S rRNA gene sequence analysis. Biochemical investigations disclosed that they possess several PGP traits, such as phosphate solubilization, indole acetic acid biosynthesis, ammonia production, nitrogen fixation, amylase production and siderophore production. Results in gnotobiotic conditions revealed an increase in fresh weight, dry weight, root length and shoot length of seedlings germinated from endophyte-primed seeds than the control (uninoculated) set in a non-host and two host rice cultivars. In net house experiments, plants germinated from Micrococcus sp. PB001, Pseudomonas sp. PB002, Methylobacterium sp. PB005 and Methylorubrum sp. PB009 primed seeds showed an increase of upto 34.06 %, 38.77 %, 182.87 %, 16.59 % and 33.52 % in chlorophyll content, number of tillers/plant, number of grains/plant, grain size and grain weight, respectively than control plant sets in the non-host rice cultivar, further validating inter-cultivar PGP abilities of these endophytes. Metabolite profiling unfolded the abundance of few metabolites that are involved in pathways associated with PGP traits, in seedlings germinated from the endophyte-primed seeds. Together, the study documents the effect of seed-transmitted endophytic bacteria on intra- and inter-cultivar PGP by modulating certain sets of metabolites in rice plant, and is promising in developing bioinoculant formulations employing these selected endophytes for enhancement of rice productivity.


Assuntos
Bactérias/metabolismo , Endófitos/metabolismo , Oryza/crescimento & desenvolvimento , Sementes/crescimento & desenvolvimento , Bactérias/isolamento & purificação , Clorofila/análise , Oryza/metabolismo , Oryza/microbiologia , Raízes de Plantas/microbiologia , RNA Ribossômico 16S/genética , Sementes/microbiologia
6.
Appl Microsc ; 50(1): 15, 2020 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-33580468

RESUMO

Sample preparation including dehydration and drying of samples is the most intricate part of scanning electron microscopy. Most current sample preparation protocols use critical-point drying with liquid carbon dioxide. Very few studies have reported samples that were dried using chemical reagents. In this study, we used hexamethyldisilazane, a chemical drying reagent, to prepare plant samples. As glandular trichomes are among the most fragile and sensitive surface structures found on plants, we used Millingtonia hortensis leaf samples as our study materials because they contain abundant glandular trichomes. The results obtained using this new method are identical to those produced via critical-point drying.

7.
Phytochemistry ; 162: 10-20, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30844491

RESUMO

Polianthes tuberosa L. (tuberose) is a widely cultivated ornamental crop in Asian countries. Different cultivars of tuberose have been developed through breeding programs in India. However, no reports on floral fragrance and metabolite contents of these cultivars are available. In this study, an attempt has been made to evaluate the levels of both volatile and non-volatile metabolites from seven different cultivars of P. tuberosa. Presence of benzenoids, phenylpropanoids, terpenoids, and few fatty acid derivatives as emitted, endogenous and glycosylated forms were revealed from the studied cultivars. Further, chemometric analyses in both supervised and unsupervised manner led to identification of patterns among the cultivars. Among the seven cultivars, four distinct clusters were obtained linking to their volatiles, flavonoids and primary metabolite levels. Metabolic variations obtained from the cultivars also suggest cross-talks between phenylpropanoid, benzenoid, and flavonoid pathways. Thus metabolite profiling reported here may help in characterization of tuberose cultivars for perfumery utility and future breeding programme.


Assuntos
Asparagaceae/metabolismo , Flores/metabolismo , Compostos Orgânicos Voláteis/química , Compostos Orgânicos Voláteis/metabolismo , Biotecnologia
8.
Physiol Plant ; 166(4): 946-959, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30324614

RESUMO

Jasminum spp. is cultivated for their fragrant flowers used in essential oil production and cosmetic uses. An attempt was made to study the temporal variations in floral scent volatiles composition including emitted, free endogenous and glycosyl-linked volatile compounds from two summer-blooming species namely, Jasminum auriculatum and Jasminum grandiflorum as well as from two winter-blooming species namely, Jasminum multiflorum and Jasminum malabaricum. The overall emitted volatile organic compounds (VOCs) were found to be highest when the matrix Porapak Q 80/100 was used with dichloromethane (DCM) as elution solvent. The floral volatile emission from bud to senescence exhibited nocturnal maxima pattern for both the summer-blooming species. Both the winter-blooming species emitted its highest concentration at noon. The free endogenous concentrations of all VOCs were low when corresponding emitted concentrations were high. Enzymatic treatment of petal extract revealed that several aromatic volatiles including aromatic alcohols and monoterpenols are synthesized and stored in the flowers as water-soluble glycosides; these compounds were shown to accumulate in higher amounts in flowers at late bud stage. These findings indicate the utilization of the precursors, i.e. the volatile-conjugates, through hydrolysis followed by their release as free-volatiles at flower opening stage. The outcome as a whole suggests a linkage among the temporal pattern of emitted volatiles, free-endogenous volatiles and glycoside-bound volatile compounds in all above studied Jasminum spp. and provided an overview of their floral volatilome.


Assuntos
Flores/metabolismo , Glicosídeos/metabolismo , Jasminum/metabolismo , Odorantes , Compostos Orgânicos Voláteis/metabolismo , Cloreto de Metileno/metabolismo
9.
Nat Prod Res ; 33(3): 435-438, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29553803

RESUMO

Emitted scent volatile profile of an orchid species Zygopetalum maculatum was studied using dynamic headspace sampling technique with four different adsorbent matrices, namely Porapak Type Q polymer (mesh size: 80/100), Tenax (mesh size: 60/80), activated charcoal and graphite. In addition, developmental variations in scent emissions and endogenous volatile levels were also investigated. Gas chromatography-mass spectrometry analysis revealed the presence of 21 volatile compounds in the headspace, which was predominantly enriched with benzenoid compounds. Among these benzenoids, o-diethylbenzene and p-diethylbenzene were the major compounds followed by benzyl acetate and methyl salicylate. Among the phenylpropanoid compounds, 2-phenylethyl acetate was the major volatile. However, as compared to benzenoids, the quantity was much lesser, indicating the inclination of phenylalanine flux towards benzenoid pathway. The outcome of this study has the implications in enhancing fragrance and vase life of orchids of the Sikkim Himalaya region and thus may further help to meet the growing market demand.


Assuntos
Odorantes/análise , Orchidaceae/química , Compostos Orgânicos Voláteis/isolamento & purificação , Adsorção , Derivados de Benzeno/análise , Derivados de Benzeno/química , Derivados de Benzeno/isolamento & purificação , Carvão Vegetal , Flores/química , Cromatografia Gasosa-Espectrometria de Massas , Siquim , Compostos Orgânicos Voláteis/química
10.
Appl Microbiol Biotechnol ; 102(17): 7389-7406, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29934653

RESUMO

Quorum sensing, the microbial communication system, is gaining importance as a therapeutic target against pathogens. The two key reasons for the rising demand of quorum sensing (QS) inhibitory molecules are low selective pressure to develop resistance by pathogens and possibility of more species-specific effects. Due to complex interactions in a unique niche of live plant tissues, endophytes, as a survival mechanism, potentially produce various bioactive compounds such as QS inhibitors. We report the isolation of an endophytic fungus Kwoniella sp. PY016 from the medicinal plant "Bahera" (Terminalia bellirica), which exhibits substantial quorum sensing inhibition and anti-biofilm activities against the standard test organism, Chromobacterium violaceum. Sugar, sugar alcohol, carboxylic acid, lipid, and phenolic classes of metabolites (predominantly xylitol) are responsible components of the metabolome for the desired bioactivity. A judicious combination of single-factor-at-a-time strategy and artificial neural network modeling combined with genetic algorithm was employed for the selection and optimization of the critical process and medium parameters. Through this newly adopted hybrid model-based optimization, the quorum sensing inhibitory activity of the endophytic metabolome was increased by ~ 30%. This is the first report on optimization of QS inhibitory activity from any fungal endophyte using such a hybrid advanced approach.


Assuntos
Antibacterianos/farmacologia , Basidiomycota/metabolismo , Endófitos/metabolismo , Metaboloma , Modelos Teóricos , Percepção de Quorum/efeitos dos fármacos , Algoritmos , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Chromobacterium/efeitos dos fármacos , Redes Neurais de Computação , Plantas Medicinais/microbiologia , Terminalia/microbiologia
11.
Microb Ecol ; 75(3): 647-661, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28894891

RESUMO

Plant-associated endophytes are recognized as sources of novel bioactive molecules having diverse applications. In this study, an endophytic yeast-like fungal strain was isolated from the fruit of eggplant (Solanum melongena) and identified as Geotrichum candidum through phenotypic and genotypic characterizations. This endophytic G. candidum isolate PF005 was found to emit fruity scented volatiles. The compositional profiling of volatile organic compounds (VOCs) revealed the presence of 3-methyl-1-butanol, ethyl 3-methylbutanoate, 2-phenylethanol, isopentyl acetate, naphthalene, and isobutyl acetate in significant proportion when analyzed on a time-course basis. The VOCs from G. candidum exhibited significant mycelial growth inhibition (54%) of phytopathogen Rhizoctonia solani, besides having mild antifungal activity against a few other fungi. The source of carbon as a nutrient was found to be an important factor for the enhanced biosynthesis of antifungal VOCs. The antifungal activity against phytopathogen R. solani was improved up to 91% by feeding the G. candidum with selective precursors of alcohol and ester volatiles. Furthermore, the antifungal activity of VOCs was enhanced synergistically up to 92% upon the exogenous addition of naphthalene (1.0 mg/plate). This is the first report of G. candidum as an endophyte emitting antifungal VOCs, wherein 2-penylethanol, isopentyl acetate, and naphthalene were identified as important contributors to its antifungal activity. Possible utilization of G. candidum PF005 as a mycofumigant has been discussed based upon its antifungal activity and the qualified presumption of safety status.


Assuntos
Antifúngicos/farmacologia , Endófitos/metabolismo , Geotrichum/metabolismo , Solanum melongena/microbiologia , Compostos Orgânicos Voláteis/farmacologia , Antifúngicos/química , Carbono/metabolismo , Meios de Cultura/química , DNA Fúngico/genética , Endófitos/genética , Endófitos/crescimento & desenvolvimento , Endófitos/isolamento & purificação , Genótipo , Geotrichum/genética , Geotrichum/crescimento & desenvolvimento , Geotrichum/isolamento & purificação , Testes de Sensibilidade Microbiana , Micélio/efeitos dos fármacos , Micélio/crescimento & desenvolvimento , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle , RNA Ribossômico 18S/genética , Rhizoctonia/efeitos dos fármacos , Rhizoctonia/crescimento & desenvolvimento , Rhizoctonia/patogenicidade , Compostos Orgânicos Voláteis/química
12.
Plant Cell Physiol ; 58(12): 2095-2111, 2017 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-29036488

RESUMO

Tuberose or Polianthes tuberosa L. is a horticultural crop of tropical origin, widely cultivated for its pleasant and intense floral fragrance in the evening. Here an investigation was made into the physiological and cell biological aspects of floral scent biosynthesis, tissue localization and emission that have not previously been examined. Volatiles collected from floral headspace were analyzed by gas chromatography-mass spectrometry (GC-MS) for identification of individual compounds and elucidation of emission patterns. Transcript accumulation and the amount of active enzyme were measured to understand the enzymatic route of scent volatile biosynthesis. Localization of scent volatiles was investigated by histochemical and ultrastructural studies. Scent emission was found to be rhythmic and nocturnal under normal day-night influence, peaking at night. Enhanced enzyme activities and transcript accumulation were recorded just prior to maximum emission. Through scanning electron microscopy (SEM) analysis, the presence of a large number of floral stomata on the adaxial surface of the tepal was revealed which might have bearing on tissue-specific emission. Guard cells of stomata responded significantly to histochemical tests, which also indicated that epidermal tissues are mostly involved in scent emission. High metabolic activity was found in epidermal layers during anthesis as shown by transmission electron microscopy (TEM) analysis. Further, new insight into the localization of scent compounds, the plausible tissue involved in their release along with the preceding ultrastructural changes at the cellular levels is presented. Finally, ultrastructural analysis of the tepal surface has been able to fill a major gap in knowledge of stomatal involvement during scent emission.


Assuntos
Asparagaceae/fisiologia , Flores/fisiologia , Flores/ultraestrutura , Odorantes/análise , Compostos Orgânicos Voláteis/análise , Acetiltransferases/genética , Acetiltransferases/metabolismo , Asparagaceae/química , Asparagaceae/ultraestrutura , Cromatografia Gasosa-Espectrometria de Massas , Liases Intramoleculares/genética , Liases Intramoleculares/metabolismo , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Análise Espaço-Temporal , Terpenos/metabolismo
13.
Plant Sci ; 256: 25-38, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28167035

RESUMO

Floral scent composed of low molecular weight volatile organic compounds. The sweet fragrance of any evening blooming flower is dominated by benzenoid and terpenoid volatile compounds. Floral scent of Jasminum sambac (Oleaceae) includes three major benzenoid esters - benzylacetate, methylbenzoate, and methylsalicylate and three major terpene compounds viz. (E)-ß-ocimene, linalool and α-farnesene. We analyzed concentrations and emission rates of benzenoids and terpenoids during the developmental stages of J. sambac flower. In addition to spatial emission from different floral parts, we studied the time-course mRNA accumulations of phenylalanine ammonia-lyase (PAL) and the two representative genes of terpenoid pathway, namely 1-deoxy-d-xylulose 5-phosphate reductoisomerase (DXR) and terpene synthase (TPS). Further, in vitro activities of several enzymes of phenylpropanoid/benzenoid pathway viz., PAL and acetyl-coenzyme A: benzylalcohol acetyltransferase (BEAT), S-adenosyl-l-methionine: benzoic acid carboxyl methyl transferase (BAMT) and S-adenosyl-l-methionine: salicylic acid carboxyl methyltransferase (SAMT) were studied. All the above enzyme activities along with the in vitro activities of DXR and TPS were found to follow a certain rhythm as observed in the emission of different benzenoid and terpenoid compounds. Linalool emission peaked after petal opening and coincided with maximal expression of JsTPS gene as evidenced from RT-PCR analyses (semi-quantitative). The maximum transcript accumulation of this gene was observed in flower petals, indicating that the petals of J. sambac flower play an important role as a major contributor of volatile precursors. The transcripts accumulation of JsDXR and JsTPS in different developmental stages and in different floral part showed that emissions of terpenoid volatiles in J. sambac flower are partially regulated at transcription levels.


Assuntos
Flores/metabolismo , Jasminum/metabolismo , Odorantes , Terpenos/metabolismo , Compostos Orgânicos Voláteis/metabolismo , Aldose-Cetose Isomerases/genética , Aldose-Cetose Isomerases/metabolismo , Alquil e Aril Transferases/genética , Alquil e Aril Transferases/metabolismo , Flores/enzimologia , Jasminum/enzimologia , Jasminum/genética , Metiltransferases/metabolismo , Fenilalanina Amônia-Liase/genética , Fenilalanina Amônia-Liase/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , RNA Mensageiro/metabolismo
14.
Front Microbiol ; 7: 1407, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27708623

RESUMO

Nutrient deficiency severely impairs the catabolic activity of indigenous microorganisms in hydrocarbon rich environments (HREs) and limits the rate of intrinsic bioremediation. The present study aimed to characterize the microbial community in refinery waste and evaluate the scope for biostimulation based in situ bioremediation. Samples recovered from the wastewater lagoon of Guwahati refinery revealed a hydrocarbon enriched [high total petroleum hydrocarbon (TPH)], oxygen-, moisture-limited, reducing environment. Intrinsic biodegradation ability of the indigenous microorganisms was enhanced significantly (>80% reduction in TPH by 90 days) with nitrate amendment. Preferred utilization of both higher- (>C30) and middle- chain (C20-30) length hydrocarbons were evident from GC-MS analysis. Denaturing gradient gel electrophoresis and community level physiological profiling analyses indicated distinct shift in community's composition and metabolic abilities following nitrogen (N) amendment. High throughput deep sequencing of 16S rRNA gene showed that the native community was mainly composed of hydrocarbon degrading, syntrophic, methanogenic, nitrate/iron/sulfur reducing facultative anaerobic bacteria and archaebacteria, affiliated to γ- and δ-Proteobacteria and Euryarchaeota respectively. Genes for aerobic and anaerobic alkane metabolism (alkB and bssA), methanogenesis (mcrA), denitrification (nirS and narG) and N2 fixation (nifH) were detected. Concomitant to hydrocarbon degradation, lowering of dissolve O2 and increase in oxidation-reduction potential (ORP) marked with an enrichment of N2 fixing, nitrate reducing aerobic/facultative anaerobic members [e.g., Azovibrio, Pseudoxanthomonas and Comamonadaceae members] was evident in N amended microcosm. This study highlighted that indigenous community of refinery sludge was intrinsically diverse, yet appreciable rate of in situ bioremediation could be achieved by supplying adequate N sources.

15.
Recent Pat Biotechnol ; 10(1): 4-11, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27634358

RESUMO

The review of patents reveals that investigation of plant volatiles and their biosynthetic pathways is a relatively new field in plant biochemistry. The diversity of structure and function of these volatiles is gradually being understood. However, the great diversity of volatile biochemicals plants emit through different parts plays numerous roles in stress resistance and other ecological interactions. From an agronomic point of view, regulation volatile production in crop plants may lead to desirable changes in plant defence, pollinator attraction and post-harvest qualities. In several crop species, genetic manipulation or metabolic channelling have led to altered emission I aroma profiles. This short review summarizes some recent cases of artificial manipulation of volatile profile in planta or in transformed microbial systems.


Assuntos
Plantas/genética , Plantas/metabolismo , Compostos Orgânicos Voláteis/metabolismo , Agricultura/métodos , Genômica/métodos , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo
16.
Planta ; 244(1): 259-74, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27059029

RESUMO

MAIN CONCLUSION: Elicitation of xanthones is mediated by ROS where Ca (2+) mediated generation of H 2 O 2 activates the shikimate pathway, a key regulator in early steps of xanthone biosynthesis in H. fastigiata. Shoot cultures of Hoppea fastigiata upon treatment with yeast extract (YE) accumulate an enhanced amount of 1,3,5-trihydroxy-8-methoxy xanthone. We demonstrated that YE treatment was followed by a rapid burst of reactive oxygen species (ROS, O2 (-) and H2O2) and subsequent increase in xanthone contents. The antioxidant enzymes (NADPH oxidase, superoxide dismutase (SOD), peroxidase and catalase) followed a similar kinetics as that of ROS, depending on their role in production or degradation. It was observed that shikimate dehydrogenase (SKDH) and shikimate kinase (SK) activities enhanced after 8 h, benzophenone synthase activity continued to rise after elicitation and peaked at 18 h. Activities of phenylalanine ammonia-lyase and 4-hydroxycinnamoyl-CoA ligase remained suppressed and unaffected, respectively, after elicitation. This suggests a possible phenylalanine-independent biosynthesis of xanthones. Successive treatment of shoots cultures with a NADPH-oxidase inhibitor diphenylene iodide and a ROS-scavenger dihydrolipoic acid showed inhibition in ROS (O2 (-) and H2O2) accumulation. These treatments were also shown to decrease the activities of SKDH and SK, leading to a suppressed amount of xanthones formation. Although O2 (-) showed continuous increase upon treatment with a SOD inhibitor diethyldithiocarbamic acid, the contents of H2O2 and xanthones were decreased, which correlates well with the reduced activities of SKDH and SK. Treatments with calcium antagonists, such as, lanthanum chloride and EGTA were also shown to block the activities of SKDH, SK, NADPH-oxidase and SOD, and consequently leading to suppressed accumulation of ROS (O2 (-) and H2O2) and xanthones.


Assuntos
Gentianaceae/metabolismo , Peróxido de Hidrogênio/metabolismo , Brotos de Planta/metabolismo , Xantonas/metabolismo , Oxirredutases do Álcool/metabolismo , Produtos Biológicos/farmacologia , Cálcio/metabolismo , Carbono-Carbono Ligases/metabolismo , Catalase/metabolismo , Cromatografia Líquida de Alta Pressão , Coenzima A Ligases/metabolismo , Expressão Gênica/efeitos dos fármacos , NADPH Oxidases/metabolismo , Peroxidase/metabolismo , Fenilalanina Amônia-Liase/genética , Fenilalanina Amônia-Liase/metabolismo , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Brotos de Planta/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Saccharomyces cerevisiae/química , Superóxido Dismutase/metabolismo , Técnicas de Cultura de Tecidos
17.
Planta ; 243(2): 305-20, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26403287

RESUMO

MAIN CONCLUSION: A metabolic shift in green hairy root cultures of carrot from phenylpropanoid/benzenoid biosynthesis toward volatile isoprenoids was observed when compared with the metabolite profile of normal hairy root cultures. Hairy roots cultures of Daucus carota turned green under continuous illumination, while the content of the major phenolic compound p-hydroxybenzoic acid (p-HBA) was reduced to half as compared to normal hairy roots cultured in darkness. p-Hydroxybenzaldehyde dehydrogenase (HBD) activity was suppressed in the green hairy roots. However, comparative volatile analysis of 14-day-old green hairy roots revealed higher monoterpene and sesquiterpene contents than found in normal hairy roots. Methyl salicylate content was higher in normal hairy roots than in green ones. Application of clomazone, an inhibitor of 1-deoxy-D-xylulose 5-phosphate synthase (DXS), reduced the amount of total monoterpenes and sesquiterpenes in green hairy roots compared to normal hairy roots. However, methyl salicylate content was enhanced in both green and normal hairy roots treated with clomazone as compared to their respective controls. Because methyl-erythritol 4-phosphate (MEP) and phenylpropanoid pathways, respectively, contribute to the formation of monoterpenes and phenolic acids biosynthesis, the activities of enzymes regulating those pathways were measured in terms of their in vitro activities, in both green and normal hairy root cultures. These key enzymes were 1-deoxy-D-xylulose 5-phosphate reductoisomerase (DXR), an early regulatory enzyme of the MEP pathway, pyruvate kinase (PK), an enzyme of primary metabolism related to the MEP pathway, shikimate dehydrogenase (SKDH) which is involved in biosynthesis of aromatic amino acids, and phenylalanine ammonia-lyase (PAL) that catalyzes the first step of phenylpropanoid biosynthesis. Activities of DXR and PK were higher in green hairy roots as compared to normal ones, whereas the opposite trend was observed for SKDH and PAL activities. Gene expression analysis of DXR and PAL showed trends similar to those for the respective enzyme activities. Based on these observations, we suggest a possible redirection of metabolites from the primary metabolism toward isoprenoid biosynthesis, limiting the phenolic biosynthetic pathway in green hairy roots grown under continuous light.


Assuntos
Daucus carota/metabolismo , Hidroxibenzoatos/metabolismo , Terpenos/metabolismo , Oxirredutases do Álcool/metabolismo , Clorofila/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Peróxido de Hidrogênio/metabolismo , Hidroxibenzoatos/química , Isomerases/metabolismo , Redes e Vias Metabólicas , Proteínas de Plantas/metabolismo , Raízes de Plantas/metabolismo , Piruvato Quinase/metabolismo
18.
J Food Sci Technol ; 52(4): 2387-93, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25825546

RESUMO

In black tea manufacturing, one of the most important steps is fermentation which influences the quality of tea. The macerated tea leaves were fermented at various temperatures (20, 25, 30, 35 °C) for different duration. Changes in polyphenoloxidase and peroxidase activities, depletion patterns of individual catechins, differences in individual theaflavin levels and formation of thearubigins were measured in leaves during fermentation. Higher stability of polyphenoloxidase and peroxidase enzymes was observed at lower temperature (20 °C), and increase in temperature, led to enzyme instability. The rate of degradation of all the catechins was found to be fastest at 35 °C and slowest at 20 °C. The formation and depletion of individual theaflavins varied with temperature and fermentation duration. The time required for the formation of maximum total theaflavins (TF) was highest at lower temperature and this time duration also varied for different theaflavins formation. Maximum amount of thearubigins (TR) content and liquor colour development was observed at 35 °C, and decrease in temperature reduced thearubigins accumulation. However, maximum brightness as well as TF/TR ratio was obtained at 20 °C, which suggests that fermentation at lower temperature is suitable for manufacturing quality black tea.

19.
J Nat Med ; 69(3): 375-86, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25900046

RESUMO

Hoppea fastigiata, an annual medicinal herb belonging to the Gentianaceae, is mostly found in South Asian countries, and is used by local tribes for various brain-related ailments. The genus possesses a unique class of compounds, xanthones, which are known for their potential against Alzheimer's and Parkinson's diseases. Limited availability and the potential pharmacological significance of the plants has led to the establishment of in vitro cultures of H. fastigiata and study of its neuroprotective principles. In vitro plantlets were established from the apical meristem of the plant in Murashige and Skoog medium with a combination of the phytohormones 6-benzylaminopurine (1 mg/L) and kinetin (0.1 mg/L), which was found to be efficacious with a growth index of 0.9 ± 0.01 after 30 days. Four different solvent extracts of in vitro cultures were evaluated for acetylcholinesterase (AChE) and monoamine oxidase A and B (MAO-A and MAO-B) inhibitory activities, amongst which the ethanolic extract showed the lowest IC50 value in all the assays. Three major compounds were isolated from the ethanolic extract and structurally confirmed as 1,5,7-trihydroxy-3-methoxyxanthone (1), 1,5-dihydroxy-3,7-dimethoxyxanthone (2) and 1,3,5-trihydroxy-8-methoxyxanthone (3). Compound 3 showed the strongest AChE inhibitory activity with mixed-type inhibition. Compounds 1 and 2 also showed promising AChE inhibitory properties with mixed and non-competitive types of inhibition, respectively. Compounds 1 and 2 showed inhibition of MAO-A (mixed and competitive, respectively) and compounds 2 and 3 showed inhibition of MAO-B (competitive and mixed, respectively). Extracts and isolated compounds showed good antioxidant capacities. The ethanolic extract and compound 2 showed the strongest antioxidant activities among the other solvent extracts and compounds, respectively.


Assuntos
Gentianaceae/química , Fármacos Neuroprotetores/química , Extratos Vegetais/química , Xantonas/química , Acetilcolinesterase/química , Animais , Antioxidantes/farmacologia , Inibidores da Colinesterase/química , Inibidores da Colinesterase/isolamento & purificação , Enguias , Proteínas de Peixes/antagonistas & inibidores , Proteínas de Peixes/química , Sequestradores de Radicais Livres/química , Sequestradores de Radicais Livres/isolamento & purificação , Gentianaceae/crescimento & desenvolvimento , Humanos , Monoaminoxidase/química , Inibidores da Monoaminoxidase/química , Inibidores da Monoaminoxidase/isolamento & purificação , Fármacos Neuroprotetores/isolamento & purificação , Extratos Vegetais/isolamento & purificação , Brotos de Planta/química , Brotos de Planta/crescimento & desenvolvimento , Xantonas/isolamento & purificação
20.
Nat Prod Res ; 29(14): 1328-35, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25583067

RESUMO

Jasmines are commercially grown for their fragrant flowers and essential oil production. The flowers of jasmine emit sweet-smelling fragrance from evening till midnight. This study was designed to study the composition and inter-specific variation of the emitted scent volatiles from flowers of four commercially cultivated Jasminum species namely, Jasminum sambac, Jasminum auriculatum, Jasminum grandiflorum and Jasminum multiflorum. Gas chromatography-mass spectrometry analysis revealed that the scent volatiles composition of these flowers was predominantly enriched with both terpenoid and benzenoid compounds. Linalool and (3E,6E)-α-farnesene were identified as the major monoterpene and sesquiterpene in all the four species, respectively. The most abundant benzenoid detected in all flowers was benzyl acetate. Comparison of volatile profiles indicated a variation in fragrance contents and types emitted from these four jasmine flowers. The outcome of this study shall help in elucidating the enzymes and genes of fragrance biosynthesis in jasmines and in aiming to create flowers with improved scent quality.


Assuntos
Flores/química , Jasminum/química , Óleos Voláteis/análise , Óleos Vegetais/análise , Compostos de Benzil/análise , Cromatografia Gasosa-Espectrometria de Massas , Jasminum/classificação , Odorantes/análise , Especificidade da Espécie , Terpenos/análise , Compostos Orgânicos Voláteis/análise
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