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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

The design and construction of a centrifugal chromatograph with electrochemical detection and enzymatic analysis applications of a multichannel electrochemical centrifugal analyzer /

Veruttipong, Paktra Lawhanuwat, January 1984 (has links)
No description available.
22

Bayesian analysis of particle tracking data using hierarchical models for characterization and design

Dhatt-Gauthier, Kiran January 2022 (has links)
This dissertation explores the intersection between the fields of colloid science and statistical inference where the stochastic trajectories of colloidal particles are captured by video microscopy, reconstructed using particle tracking algorithms, and analyzed using physics-based models and probabilistic programming techniques. Although these two fields may initially seem disparate, the dynamics of micro- and nano-sized particles dispersed in liquids at room temperature are inherently stochastic due to Brownian motion. Further, both the particles under observation and their environment are heterogeneous, leading to variability between particles as well. We use Bayesian data analysis to infer the uncertain parameters of physics-based models that describe the observed trajectories, explicitly modeling the hierarchical structure of the noise under a set of varying experimental conditions. We set the stage in Chapter 1 by introducing Robert Brown's curious observation of incessantly diffusing pollen grains and Albert Einstein's statistical physics model that describes their motion. We analyze Jean Baptiste Perrin's data from Les Atomes using a probabilistic model to infer the uncertain diffusivities of the colloids. We show how the Bayesian paradigm allows us to assign and update our credences, before and after observing this data and quantify the information gained by the observation. In Chapter 2, we build on these concepts to provide insight on the phenomenon of enhanced enzyme diffusion, whereby enzymes are purported to diffuse faster in the presence of their substrate. We develop a hierarchical model of enzyme diffusion that describes the stochastic dynamics of individual enzymes drawn from a dispersed population. Using this model, we analyze single molecule imaging data of urease enzymes to infer their uncertain diffusivities for different substrate concentrations. Our analysis emphasizes the important role of model criticism for establishing self-consistency between experimental observations and model predictions; moreover, we caution against drawing strong conclusions when such consistency cannot be established. In Chapter 3, we automate, and optimize the data acquisition process, tuning a resonant acoustic cell using minimal experimental resources. By iterating a cycle of observation, inference, and design, we select the frequency the applied signal and the framerate of the data acquisition, garnering the same amount of information as a grid search approach with a fraction of the data. Finally, in Chapter 4, we discuss the role of Bayesian inference and design to optimize functional goals and discuss selected examples on where black-box techniques may prove useful. We review the current state of the art for magnetically actuated colloids and pose the search for autonomous magnetic behaviors as a design problem, offering insight as we seek to augment and accelerate the capabilities of micron scale magnetically actuated colloids using modern computational techniques.
23

Studies on maize beta glucosidase gene-enzyme system

Rifaat, Mahmoud M. January 1988 (has links)
Maize ß-glucosidase is implicated in phytohormone catabolism, disease resistance mechanisms, and also the catabolism of various ß-D-glucosides. The enzyme expressed in maize sporophytes is encoded by a highly polymorphic locus, Glul (chromosome 10). In the present study, maize ß-glucosidase was purified to homogeneity by using differential solubility and chromatography. The enzyme is soluble and synthesized adaptively after germination. The isoelectric point (pl) of the native enzyme is 4.9-5.0 and its temperature and pH optima are 40°C and 6.8, respectively. The active enzyme is temperature·sensitive and composed of two identical, non-covalently associated and catalytically inactive polypeptides (60 kD each). Enzyme catalysis shows dominant aryl ß-glucosidase and ß-fucosidase activities compared to cellobiase activity. Activity is (1) influenced by the configuration of the C-4 and C-6 atoms on the glycone moeity and by the substrate chain length, (2) possibly mediated by an imidazole ring and a terminal α-amino group in the enzyme catalytic and binding sites, respectively, (3) dependent on intra-chain disulfide bonds to maintain the enzyme conformation, and (4) inhibited competitively by the end product, glucose. The sporophytic specificity of Glul expression might be controlled by tightly linked cis- and trans- acting regulatory elements. One of the several null mutations, with an apparent allelism to Glul locus, (l) complements in trans when combined with normal Glul alleles, and (2) probably affects a shift in the tissue-specific expression of Glul locus (from sporophytic to gametophytic). Another structural gene, GIu3, encoding a soluble, sporophyte-specific, and electrophoretically-invariant ß-glucosidase isoenzyme is present based on hydrodynamic properties, size, surface net charge, peptide map, quaternary structure, and enzyme kinetics. / Ph. D.
24

PyrH and PrnB crystal structures

De Laurentis, Walter January 2006 (has links)
Determination of the three-dimensional structure of enzymes at atomic resolution is a key prerequisite for elucidation of molecular mechanisms of catalysis and catalysis mechanism prediction. X-ray protein crystallography is the most widely used method today for determining protein structures. In this thesis we describe the expression, purification, crystallization and structure solution of two new enzymes: PyrH and PrnB. PyrH is a member of the new emerging family of FADH dependent tryptophan halogenases. It catalyzes the regioselective halogenation of tryptophan at the C-5 position of the indole ring. Elucidation of its structure (Chapter 2) and comparison with PrnA, aregioselective 7th tryptophan halogenase whose structure has already been solved confirmed the proposed mechanism of action for this class of enzymes. PrnB is the only enzyme known to perform exquisite and peculiar ring rearrangement chemistry: it converts 7-Cl-tryptophan and tryptophan into respectively monodechloroaminopyrrolnitrin and aminophenylpyrrole. We developed a method for expression and purification of milligrams of pure and homogeneous recombinant PrnB (Chapter 3). We identified suitable crystallization conditions and determined PrnB structure (Chapter 4). Analysis of the PrnB structure helped us to propose a reaction mechanism for this unique enzyme.
25

Cellulolytic and hemicellulolytic enzymes of flammulina velutipes.

January 1994 (has links)
by Cheung Pui Yi. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1994. / Includes bibliographical references (leaves 124-135). / Abstract --- p.ii / Acknowledgements --- p.iv / List of Tables --- p.viii / List of Figures --- p.ix / List of Abbreviations --- p.xiii / Chapter Chapter 1 --- Introduction / Chapter 1.1 --- General Background --- p.1 / Chapter 1.2 --- Occurrence and Structure of Cellulose --- p.1 / Chapter 1.3 --- Occurrence and Structure of Hemicelluloses --- p.4 / Chapter 1.4 --- Biodegradation of Cellulose and Hemicelluloses --- p.4 / Chapter 1.4.1 --- Cellulolytic and Hemicellulolytic Microorganisms --- p.4 / Chapter 1.4.2 --- Enzymes Involved in Cellulose Degradation --- p.10 / Chapter 1.4.2.1 --- "Endo-1,4-β-glucanases" --- p.12 / Chapter 1.4.2.2 --- "Exo-1,4-β-glucanases" --- p.14 / Chapter 1.4.2.3 --- β-Glucosidases --- p.16 / Chapter 1.4.2.4 --- Oxidative Enzymes --- p.18 / Chapter 1.4.3 --- Synergistic Action between Cellulolytic Enzymes --- p.19 / Chapter 1.4.4 --- Enzymes Involved in Hemicellulose Degradation --- p.21 / Chapter 1.4.4.1 --- "Endo-1,4-β-xylanases" --- p.22 / Chapter 1.4.4.2 --- β-Xylosidases --- p.24 / Chapter 1.4.4.3 --- Other Xylanolytic Enzymes --- p.24 / Chapter 1.4.5 --- Synergistic Action between Hemicellulolytic Enzymes --- p.25 / Chapter 1.5 --- Flammulina velutipes --- p.26 / Chapter 1.6 --- Aims of the Present Investigation --- p.27 / Chapter Chapter 2 --- Materials and Methods / Chapter 2.1 --- Organism --- p.28 / Chapter 2.2 --- Culture Medium --- p.28 / Chapter 2.3 --- Determination of the Optimal Growth pH of Flammulina velutipes --- p.29 / Chapter 2.4 --- "Preparation of Inoculum, Cultivation and Harvest of Fungal Cultures" --- p.30 / Chapter 2.5 --- Enzyme Assays --- p.30 / Chapter 2.5.1 --- "Exo-1,4-β-glucanase" --- p.30 / Chapter 2.5.2 --- "Endo-1,4-β-glucanase" --- p.31 / Chapter 2.5.3 --- "Endo-1,4-β-xylanase" --- p.34 / Chapter 2.5.4 --- Extracellular β-Glucosidase --- p.36 / Chapter 2.5.5 --- Cell-Associated β-Glucosidase --- p.38 / Chapter 2.5.6 --- Extracellular β-Xylosidase --- p.38 / Chapter 2.5.7 --- Cell-Associated β-Xylosidase --- p.38 / Chapter 2.6 --- Determination of Optimal Temperatures for Cellulolytic and Xylanolytic Enzymes --- p.39 / Chapter 2.7 --- Determination of the Optimal pH for Enzyme Reaction --- p.39 / Chapter 2.8 --- Protein Determination --- p.39 / Chapter 2.9 --- Determination of Enzyme Induction Patterns --- p.42 / Chapter 2.10 --- Elucidation of Cellulase Production Patterns in F. velutipes --- p.43 / Chapter 2.10.1 --- Native Polyacrylamide Gel Electrophoresis --- p.43 / Chapter 2.10.2 --- Activity Staining for Endoglucanases --- p.43 / Chapter 2.10.3 --- Activity Staining for β-Glucosidases --- p.44 / Chapter 2.10.4 --- Protein Staining --- p.44 / Chapter 2.10.5 --- Preparative Polyacrylamide Gel Electrophoresis --- p.44 / Chapter 2.10.6 --- Separation of Proteins and Partial Purification of Different Cellulase Species after Preparative Polyacrylamide Gel Electrophoresis --- p.45 / Chapter Chapter 3 --- Results / Chapter 3.1 --- Determination of the Optimal pH for Fungal Growth --- p.46 / Chapter 3.2 --- Determination of the Optimal Temperature for Cellulolytic and Xylanolytic Enzyme Activity --- p.48 / Chapter 3.3 --- Determination of the Optimal pH for Enzyme Reaction --- p.64 / Chapter 3.4 --- Time Course Experiments on the Production of Cellulolytic and Hemicellulolytic Enzymes --- p.72 / Chapter 3.4.1 --- Production of Cellulolytic Enzymes --- p.72 / Chapter 3.4.2 --- Production of Hemicellulolytic Enzymes --- p.77 / Chapter 3.5 --- Determination of Enzyme Induction Patterns --- p.82 / Chapter 3.5.1 --- Induction of Exoglucanase Production --- p.82 / Chapter 3.5.2 --- Induction of Endoglucanase Production --- p.84 / Chapter 3.5.3 --- Induction of Extracellular β-Glucosidase Production --- p.86 / Chapter 3.5.4 --- Induction of β-Xylanase Production --- p.88 / Chapter 3.5.5 --- Induction of Extracellular β-Xylosidase Production --- p.90 / Chapter 3.5.6 --- Changes in Extracellular Protein Levels in DMS Media Supplemented with Different Substrates --- p.92 / Chapter 3.5.7 --- Changes in Reducing Sugar Levels in DMS Media Supplemented with Different Substrates --- p.94 / Chapter 3.6 --- Partial Purification of Different Cellulases Species Produced by Flammulina velutipes --- p.96 / Chapter 3.6.1 --- Native Polyacrylamide Gel Electrophoresis --- p.96 / Chapter 3.6.2 --- Activity Staining for Endoglucanases --- p.96 / Chapter 3.6.3 --- Activity Staining for β-Glucosidases --- p.96 / Chapter 3.6.4 --- Assay of Cellulolytic Enzymes after Preparative Polyacrylamide Gel Electrophoresis --- p.101 / Chapter Chapter 4 --- Discussion / Chapter 4.1 --- Optimal Conditions for Cellulolytic and Hemicellulolytic Enzymes of F. velutipes --- p.105 / Chapter 4.1.1 --- Optimal Temperature for Enzymic Reaction --- p.105 / Chapter 4.1.2 --- Optimal pH for Enzymic Reaction --- p.106 / Chapter 4.2 --- Production of Cellulolytic and Hemicellulolytic Enzymes --- p.109 / Chapter 4.2.1 --- Production of Cellulolytic Enzymes --- p.109 / Chapter 4.2.2 --- Production of Hemicellulolytic Enzymes --- p.110 / Chapter 4.3 --- Enzyme Induction Patterns --- p.111 / Chapter 4.4 --- Partial Purification of Different Cellulase Species Produced by Flammulina velutipes --- p.116 / Chapter 4.5 --- Conclusion --- p.121 / Chapter 4.6 --- Further Studies --- p.123 / List of References --- p.124
26

Structural and functional analysis of SUMO specific proteases. / CUHK electronic theses & dissertations collection

January 2007 (has links)
During the activation and transferring process, E1 and E2 form a thioester-linkage with SUMOs. By using an in vitro assay, it is demonstrated that SENP1 is able to cleave the thioester-linkage between SUMO-1/SUMO-3 and E1/E2. This finding suggests that SUMO proteases regulate the sumoylation pathway, not only during maturation and deconjugation, but also in the E1 activation and E2 conjugation processes. / Recently, reactive oxygen species have been demonstrated to influence the equilibrium of sumoylation-desumoylation. Here, by in vitro assay, it is shown that H2O2 induces formation of inter-molecular disulfide linkage of human SUMO protease SENP1, via the active-site Cys 603 and a unique residue Cys 613. Such reversible modification confers higher enzyme activity recovery which is also observed in yeast Ulp1, but not in human SENP2, suggesting its protective role against irreversible sulfhydryl oxidation. The physiological relevance of the disulfide-linked dimer of SENP1 is also detected in cultured cells upon oxidative stress. The modifications are further verified by the crystal structures of Ulp1 with catalytic cysteine oxidized to sulfenic, sulfinic and sulfonic acids. The current findings suggest that, in addition to SUMO conjugating enzymes, SUMO proteases may act as redox sensors and effectors, which modulate the desumoylation pathway and allow immediate specific cellular responses to oxidative stress. / SUMO (small ubiquitin-related modifier) is a member of the ubiquitin-like protein family that is highly conserved in all eukaryotic organisms and regulates cellular function of a variety of target proteins. SUMO proteins are expressed in their precursor forms and precursor processing involves cleavage of the residues after the conserved 'GG' region by the hydrolytic activity of SUMO-specific protease. The exposed second glycine then forms a covalent bond with the epsilon-amino group of a substrate lysine residue at the psiKxE motif by a cascade of SUMO El, E2 and E3 ligases. As a reversible modification, SUMO proteases can cleave SUMOs from their substrates during de-conjugation process. / To date, four SUMO family members, SUMO-1, -2, -3 and -4 and six SUMO proteases, SENP1--3 and 5-7 (where SENP stands for sentrin-specific protease) have been identified in human. By characterizing the maturation reactions of SUMO-1, -2 and -3 catalyzed by SENP1, it is demonstrated that SENP1 contains the highest maturation efficiency for SUMO-1, followed by SUMO-2 and SUMO-3. By mutagenesis study, it is further identified that the two amino acids immediately after GG motif could influence the maturation efficiency of SENP1. By comparison with another investigation which showed the preference of the maturation reaction of SUMO-2 by SENP2, the results suggest that SUMO proteases with specific tissue distribution control the availability of different mature SUMOs in human. / To gain a deeper insight into the molecular basis of maturation and de-conjugation processes catalyzed by SENP1, it has been determined, at 2.8 A resolution, the X-ray structure of a complex between the catalytic domain of SENP1C(C603S) and matured SUMO-1. The structure shows that the substituted serine residue does not undergo any local structural rearrangements at the active site as observed in the previously solved SENP2/SUMO-1 complex structure. This finding suggests that SUMO proteases require a self-conformational change prior to the cleavage reaction, and further disclose the cleavage mechanism of the hydrolytic reactions catalyzed by SUMO proteases. Moreover, analysis of the interface of SENP1 and SUMO1 has identified four amino acids that are unique in SENP1 sequence and facilitate the interaction of SENP1 and SUMO-1. / Xu, Zheng. / "July 2007." / Advisers: Shannon Au Wing Ngor; Tzi-Bun Ng. / Source: Dissertation Abstracts International, Volume: 69-01, Section: B, page: 0125. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (p. 181-194). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.
27

VP4 : a putative protease encoded by infectious bursal disease virus.

Scholfield, Nicola Gillian. 19 December 2013 (has links)
Infectious bursal disease virus (IBDV) causes an acute and highly contagious disease affecting young chickens, which is responsible for significant losses in the poultry industry world-wide. The virus specifically infects and destroys B-cell precursors within the bursa of Fabricius, an avian lymphoid organ, leading to immunosuppression. IBDV has a bi-segmented, double-stranded RNA genome. The larger segment encodes a 110-kDa precursor polyprotein, designated NH₂-VPX-VP4-VP3-COOH, in a single open reading frame. The autocatalytic processing of this precursor into mature proteins is a critical step in viral replication and VP4 is the putative protease responsible for this cleavage. This study concerns the development of a strategy to clone and express recombinant VP4 and describes the use of VP4 as a marker for rapid and effective detection of IBDV. VP4 cDNA was produced and amplified by optimisation of a reverse transcription coupled to the polymerase chain reaction (RT-PCR), providing a clear and sensitive assay. Anti-peptide antibodies were raised against a selected peptide from VP4 and were used to probe homogenates of infected bursae for the native protein to assess their potential for immunological detection. These antibody-related results are promising though inconclusive, due to the complex nature of the assayed sample. Amplified VP4 cDNA from KwaZulu-Natal strains of IBDV isolated from 1989 to 1997 was also examined by restriction fragment length polymorphism (RFLP) analysis to determine the relatedness of local IBDV to global strains. All KwaZulu-Natal samples produced identical patterns, which were most similar to one of ten international strains examined, namely, the British strain UK661. Samples infected with IBDV were also probed for VP4 activity. Double basic amino acid cleavage sites have been proposed for the putative protease and infected samples were assayed for activity against the fluorogenic peptide Cbz-Arg-Arg-AMC. Demonstrably higher activity was found in infected versus uninfected samples, although the origin of this activity is unclear. The findings in this study suggest that VP4 warrants further attention, both as a marker for infectious bursal disease, and as a novel viral protease. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2000.
28

Postsynthetic Modifications of Glycolytic Enzymes of the Geriatric Immune System and in Fibroblasts from Premature Aging Diseases

Tollefsbol, Trygve O. 08 1900 (has links)
During mitogen-induced transformation of human lymphocytes, phosphoglycerate kinase (PGK) exhibits new electrophoretic forms (pl=8.5-8.9). Electrophoresis and electrofocusing showed that the new forms are not due to expression of the autosomally linked isozyme found in semen (PGK-B; pl=9.7). The multiple electrophoretic forms are the result of protease modification of sex-linked PGK-A isozyme.When peripheral lymphocytes from young persons are stimulated in vitro with phytohemagglutinin, a selective increase in the levels of the glycolytic enzymes occurs concomitantly with blastogenesis. Human lymphocytes from a geriatric population were also subjected to mitogen stimulation. The initial levels of the enzymes were essentially identical in lymphocytes from young and old subjects as were mitogenfree cultured controls. However, during mitogen stimulation the cells from the old subjects failed to increase the glycolytic enzymes. This inability to activate glycolysis may be related to the decline in cell-mediated immunity which occurs with advancing age. Triosephosphate isomerase (TPI) has an increased thermolabile component in skin fibroblasts from patients with progeria (41.4 per cent)and Werner's syndrome (20.1 per cent) when compared with normal fibroblasts (0-3 per cent). The incorporation of various protease inhibitors failed to affect the percentages of heat-labile triosephosphate isomerases. The labile component appears to be identical to the deamidated form of the enzyme which accumulates in other aging cells. Isoelectric focusing demonstrated increased quantities of the deamidated TPI-A form in progeria and Werner's syndrome fibroblasts as compared to normal. The deamidated TPI-A was considerably more labile than the native TPI-B indicating the increased lability of triosephosphate isomerase in premature aging syndrome fibroblasts is due to an accumulation of the deamidated form of the enzyme. The levels of several proteases were found to be diminished in progeria fibroblast extracts as compared to normal. A deamidation mechanism of enzyme degradation plays a key role in the normal cellular catabolism of this enzyme and the mechanism for accumulation of defective forms in aging cells is apparently exacerbated by an impaired proteolytic capacity.
29

Analysis of genes and enzymes involved in the degradation of cellulose and proteins by Butyrivibrio fibrisolvens H17c

Berger, Eldie January 1990 (has links)
Bibliography: pages 147-169. / Butyrivibrio fibrisolvens H17c is a gram-negative obligate anaerobic bacterium found in the rumen of most ruminants. The aim of this thesis was to investigate the enzymes produced by B. fibrisolvens H17c involved in the degradation of cellulose, xylan, and protein. A library of chromosomal DNA fragments from B. fibrisolvens H17c was established in the plasmid pEcoR251, an Escherichia coli positive selection vector. The library was screened for genes expressing cellulase, xylanase, and protease activity. Two genes expressing endo-β-1,4-glucanase and cellodextrinase activity were cloned in E. coli as host. The gene expressing endo-β-1,4-glucanase activity (end1) was cloned on a recombinant plasmid pES400. The end1 gene was located on a 6.8 kb DNA fragment and expressed from its own promoter in the E. coli host. It was shown that 64% of the endoglucanase activity was located in the periplasm of the E. coli host. TnphoA mutagenesis indicated the presence of a functional E. coli-like signal peptide. The nucleotide sequence of end1 was determined and the amino acid sequence (547 amino acids) deduced. The catalytic domain of End1 showed very good similarity to the catalytic domain of the Clostridium thermoceiium EGE endoglucanase. End1 also has a non-catalytic domain similar to the binding domains of the CenA and Cex cellulases from Ceilulomonas fimi The gene expressing cellodextrinase activity (ced1) was cloned on a recombinant plasmid pES500. This gene was located on a 3.55 kb fragment and was also expressed from its own promoter in the E. coli host. The Ced1 enzyme was also exported to the periplasm of the E. coli host, but did not contain a functional E. coli-like signal peptide. The nucleotide sequence was determined and the deduced amino acid sequence (547 residues) showed high similarity to the catalytic domain of the C. thermocellum EGD endoglucanase. The proteins of End1 and Ced1 showed no similarity. The End1 and Ced1 enzymes were characterized using a range of different substrates. The End1 enzyme showed optimal activity at pH 5.6 and 45°C. Optimal activity for the Ced1 enzyme was obtained at pH 6.6 and 50°C. The proteolytic activity of B. fibrisolvens H17c was characterized using gelatin-SD5-PAGE. Ten bands of protease activity with apparent molecular weights ranging between 42 000 and 101 000 were detected at different stages during the growth cycle. The effect of protease inhibitors indicated that all ten protease bands were serine proteases. Optimal activity was observed between pH 6.0 to 7.5 and at a temperature of 50°C. The proteolytic activity of B. fibrisolvens H17c varied depending on the type of carbohydrate substrate in the medium, and was positively correlated with the growth rate.
30

Produção de óleo essencial associado à deficiência hídrica em plantas Ocimum basilicum L. cv. genovese

Leonardo, Marcelo [UNESP] 05 March 2007 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:32:43Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-03-05Bitstream added on 2014-06-13T18:44:01Z : No. of bitstreams: 1 leonardo_m_dr_botfca.pdf: 849833 bytes, checksum: 14dfc79b16640209ce661eb409949474 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Universidade Estadual Paulista (UNESP) / Um dos mais importantes fatores ambientais e agronômicos que afetam a produção de metabólitos secundários em plantas é a água. Quantidade limitada de água tem efeito negativo sobre o crescimento e desenvolvimento das plantas. Entretanto, a deficiência hídrica (DH), muitas vezes tem se mostrado positiva no acúmulo de constituintes ativos em espécies medicinais, aromáticas e condimentares. Verificou-se a influência da DH na participação de assimilados, acúmulo e na composição do óleo essencial em manjericão (Ocimum basilicum L.). Paralelamente, foram avaliados parâmetros bioquímicos relacionados com a resposta das plantas a DH. Os tratamentos foram constituídos por dois blocos, T1 (controle) que foi mantido sempre irrigado e T2 (DH) submetido a três níveis de DH. Nas plantas dos tratamentos do bloco T2 (DH), foi suspenso o fornecimento de água quando 50% das plantas iniciaram seu florescimento. Observou-se que as plantas cultivadas sob DH, responderam com aumento da concentração de óleo essencial na inflorescência e nas folhas. O maior rendimento de óleo por planta, foi encontrado nas plantas do controle, principalmente no tecido da inflorescência, inversamente do observado para o tecido foliar. Em termos qualitativos, a análise dos componentes do óleo revelou que os diferentes níveis de DH não alteraram o padrão conhecido para esta espécie. Constatou-se que todos os parâmetros biométricos foram influenciados negativamente pela DH. A análise da atividade enzimática indicou que o estresse causado por DH ativou todas as enzimas relacionadas ao sistema de resposta antioxidativo, além de induzir ao acúmulo de L-prolina. / The water is one of the most important agronomic and environmental factors that affect the production of secondary metabolites in plants. Limited amount of water has negative effect on growth and development of plants. However, the hydric deficiency (HD), a lot of times have been shown positive in the active constituents accumulation in medicinal species, aromatic and spices. The influence of HD was verified in participation of assimilate, accumulation and in the essential oil composition of basil (Ocimum basilicum L.). At the same time, biochemical parameters related with HD in plants were studied. The treatments were constituited by two blocks, T1 (control) that was maintained well irrigated and T2 (HD) submitted to three levels of HD. In T2 (HD) treatments, the water supply was suspended when 50% of the plants began flowering. In plants cultivated under HD was observed that the essential oil concentration was increased in the inflorescences and leaves. The largest oil income was found in the plants of control, mainly in inflorescences material, inversely of observed in leaves material. In qualitative terms, the oil components analysis revealed that the different levels of HD didn't alter the known standarts for this species. It was verified that all of the biometrical parameters were negatively influenced by HD. The enzymatic activity analysis indicated that the stress caused by HD had activated all of the enzymes related to the antioxitative response system, besides inducing the accumulation of L-proline.

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