Please read the abstract in the section 00front of this document / Dissertation (MSc (Plant Physiology))--University of Pretoria, 2005. / Plant Science / unrestricted

No presente estudo, foram avaliados o potencial dos óleos essenciais das espécies Cymbopogon nardus L. (Capim citronela), Copaifera sp. (Copaíba) e Ocimum basilicum L. (Manjericão) no controle de fitopatógenos associados a sementes comercializadas de manjericão; também foi determinada a composição química do óleo essencial de Morinda citrifolia L. (Noni) e sua atividade fungitóxica in vitro e in vivo no controle de fitopatógenos causadores de helmintosporiose, bem como seu potencial na indução de síntese de fitoalexinas e enzimas envolvidas nos mecanismos resistência a doenças e defesa em plantas de milho. Devido à complexidade da composição química dos óleos essenciais, tais substâncias têm apresentado potencial promissor no controle de agentes fitopatogênicos. Observou-se que os óleos essenciais apresentam potencial de inibição da micoflora associada às sementes de O. basilicum, e o óleo essencial de C. nardus foi eficiente no controle in vitro inibindo a germinação de conídios e o crescimento micelial do fitopatógeno Curvularia sp., além de ter sido também, eficaz no controle preventivo da mancha de Curvularia em plantas de O. basilicum. Apesar de não haver informações quanto a utilização do óleo essencial de frutos de M. citrifolia no controle de fitopatógenos, os resultados demonstraram que o óleo essencial desta espécie foi eficiente na inibição do crescimento micelial e na severidade da doença helmintosporiose do milho causada pelos fitopatógenos Bipolaris maydis e Exserohilum turcicum, apresentando valores de ACPD inferiores aos valores observados quando as plantas foram pulverizadas com fungicida. Também observou-se que o óleo essencial apresentou potencial na síntese de fitoalexinas envolvidas nos mecanismos de resistência e defesa vegetal em plantas de milho. / At the present study we evaluated the potential of essential oils of species Cymbopogon Nardus L. (Citronella grass), Copaifera sp. (Copaiba) and Ocimum basilicum L. (Basil) in control phytopathogens associated seeds marketed of O basilicum; the essential oil chemical composition of Morinda citrifolia L. (Noni) and its fungitoxic activity in vitro and in vivo in control of phytopathogens causers of leaf blotch, as well as the its potential for phytoalexin synthesis and enzymes induction involved in the mechanisms disease resistance and defense in maize plants. Due to the complexity of the chemical composition of essential oils, such substances have presented promising potential in the control of pathogenic agents. Observed that essential oils presented potential for inhibition of mycoflora associated to O. basilicum seeds, and the essential oil of C. nardus was effective in vitro control inhibiting spore germination and mycelial growth of the phytopathogen Curvularia sp., besides having been also, effective in the preventive control of Curvularia spot disease in O. basilicum plants. Although there is no information about the use of essential oil of M. citrifolia fruits on the control of phytopathogens, the results showed that the essential oil of this species was effective in inhibiting the mycelial growth and the blotch severity of disease caused by phytopathogens Bipolaris maydis and Exserohilum turcicum, presenting AUDPC values lower than those observed when plants were sprayed with fungicides. It was also observed that the essential oil presented potential in phytoalexin and enzymes synthesis involved in resistance and defense mechanisms in maize plants.

Thesis (MSc)--Stellenbosch University, 2001. / ENGLISH ABSTRACT: Grapevine is constantly under attack from a wide variety of pathogens including viruses, bacteria and fungi. In order to ensure survival, the grapevine has developed a vast array of defense mechanisms to combat invading organisms. A key element of this disease resistance is the production of phytoalexins, of which resveratrol is the primary component. The synthesis of resveratrol, together with other structural and biochemical defense mechanisms equips the plant to combat a number of pathogens resulting in the production of healthy grapes for the vinification of top quality wine. As part of the active disease response resveratrol is synthesised de novo in the berry skin at the site of infection, on recognition of the pathogen. Here it is able to limit the damage caused by the pathogen as well as preventing it from spreading. This gives the plant the opportunity to initiate its systemic acquired resistance thereby protecting the rest of the plant and preventing secondary infections. The fermentation of red wine on the grape skins allows for the extraction of resveratrol from the skin into the wine. Red wines therefore have a significantly higher concentration of resveratrol than white varieties, which contain little or no resveratrol at all. It is for this reason that the moderate consumption of wine, in particular red wine, is synonymous with a healthy lifestyle. The antioxidant and anti-inflammatory activities of resveratrol are important contributors to the cardiovascular benefits derived from the consumption of red wine. It now seems, however, that significant cardiovascular protection is derived from the synergistic action of resveratrol, the polyphenols and the alcohol in wine. With the wholesomeness of any food or beverage being of extreme importance, the aim of this project was to manipulate wine yeast to produce resveratrol during fermentation. This required the introduction of an entire metabolic pathway, by integrating plant genes into the yeast. Resveratrol synthase utilises three malonyl-CoA and one pcoumaroyl- CoA molecules to produce one molecule of resveratrol, Saccharomyces cerevisiae produces malonyl-CoA but no p-coumaroyl-CoA. Therefore, the following genes were obtained to enable yeast to produce p-coumaroyl-CoA: PAL, encoding phenylalanine ammonia-lyase to convert phenylalanine into cinnamic acid; C4H, encoding cinnamate-4- hydroxlyase to convert cinnamic acid into p-coumaric acid; and 4CL9 or 4CL216 encoding CoA-ligases to convert the p-coumaric acid into p-coumaroyl-CoA. To attain high-level expression, the genes were subcloned under the control of the phosphoglycerate kinase gene (PGK1) promoter and terminator. Due to integration problems with these expression cassettes and the fact that the yeast was able to consume p-coumaric acid, the 4CL9, 4CL216 and Vst1 (encoding resveratrol synthase) genes were subcloned under the control of the alcohol dehydrogenase (ADH2) and PGK1 promoters into episomal plasmids, respectively. A laboratory yeast strain containing both the Vst1 and 4CL9, or the Vst1 and 4CL216 genes was evaluated for its ability to utilise p-coumaric acid and produce resveratrol. Northem analysis confirmed that the Vst1, 4CL9 and 4CL216 genes were transcribed and over-expressed compared to the control strain. The transformants expressing the CoA-ligase genes utilised the p-coumaric acid faster than the control, although it was not possible to determine whether p-coumaroyl-CoA was produced. No resveratrol was produced under the assay conditions used. The results indicated that the yeast is unable to produce active resveratrol synthase, which is required to catalyse the final reaction in the production of resveratrol. Posttranslational modification, such as overglycosylation and disulphide formation, of the heterologous protein in yeast has been indicated as the possible reason for the lack of enzyme activity. This introduces an exciting area of research for the development of biotechnological tools with the ability to increase the production of active heterologous proteins in yeast. / AFRIKAANSE OPSOMMING: Wingerde word voortdurend deur 'n groot verskeidenheid patogene, insluitende virusse, bakteriee en swamme, aangeval. Ten einde oorlewing te verseker, het die wingerdstok In wye reeks verdedigingsmeganismes ontwikkel om weerstand te bied teen indringerorganismes. 'n Belangrike faktor in hierdie weerstand teen siektes is die produksie van fitoaleksiene, waarvan resveratrol die hoofkomponent is. Oeur die sintese van resveratrol, asook ander strukturele en biochemiese verdedigingsmeganismes, word die plant toegerus om weerstand te kan bied teen In hele aantal patogene ten einde gesonde druiwe te produseer wat gebruik kan word vir die vinifikasie van topgehalte wyn. As deel van die aktiewe reaksie teen siektes, word resveratrol de novo in die dop van die korrel by die plek van infeksie gesintetiseer sodra 'n patogeen herken word. Hier kan dit die skade deur die patogeen veroorsaak, beperk en verhoed dat dit versprei. Oit gee aan die plant die geleentheid om sy sistemies-verworwe weerstand te inisieer, en daardeur die res van die plant te beskerm, sowel as sekondere infeksies te verhoed. Die fermentasie van rooiwyn op die druifdoppe maak voorsiening vir die ekstraksie van resveratrol uit die dop na die wyn. Die konsentrasie van resveratrol in rooiwyn is dus beduidend hoer as in die wit varietelte, wat geen of baie min resveratrol bevat. Oit is dan juis die rede waarom die matige inname van wyn, veral rooi wyn, gesien word as In integrale deel van 'n gesonde leefwyse. Resveratrol se aktiwiteit as antioksidant en antiinflammatoriese middel lewer In belangrike bydrae tot die kardiovaskulere voordele wat verkry word uit die inname van rooiwyn. Oit blyk egter nou dat die beduidende kardiovaskulere beskerming gesetel is in die sinergistiese werking van resve ratro I, die polifenole en die alkohol in wyn. Aangesien die heilsaamheid van enige voedsel of drank van die uiterste belang is, was dit die doel van hierdie projek om wyngis te manipuleer ten einde tydens die fermentasieproses resveratrol te produseer. Hiervoor moes 'n volledige metaboliese pad daargestel word deur plantgene in die gis te inkorporeer. Resveratrol-sintase maak gebruik van drie maloniel-KoA-molekules en een p-kumarotel-Kos-molekule om een molekule resveratrol te produseer. Saccharomyces cerevisiae produseer maloniel-KoA, maar nie p-kumaroiel-Kcs, nie. Oie volgende gene is dus aangewend om die gis in staat te stel om p-kumarolel-Koe, te produseer: PAL, wat fenielalanien-ammoniak-liase enkodeer om fenielalanien om te sit na kaneelsuur; C4H, wat sinnamaat-4-hidroksliase enkodeer om kaneelsuur om te sit na p-kumaarsuur; en 4CL9 of 4CL216 wat KoA-ligases enkodeer om p-kumaarsuur om te sit na p-kumarolel-Kos, Om hoevlak-uitdrukking te verkry, is die gene gesubkloneer onder beheer van die fosfogliseraat-kinase-geen(PGK1)- promotor en -terminator. As gevolg van integrasieprobleme met hierdie uitdrukkingskassette en die feit dat die gis die p-kumaarsuur kon verteer, is die 4CL9-, 4CL216- en Vst1- (wat resveratrol-sintase enkodeer) gene na episomale plasmiede gesubkloneer onder beheer van die alkohol-dehidrogenase(ADH2)- en PGK1-promotors onderskeidelik. 'n Laboratorium-gisstam wat 6f beide die Vst1-geen en die 4CL9-geen, 6f die Vst1-geen en die 4CL216-geen bevat het, is geevalueer vir die verrnoe om pkumaarsuur te benut en resveratrol te produseer. Noordelike klad analises het bevestig dat die Vst1-, 4CL9- en 4CL216-gene getranskribeer en ooruitgedruk was in vergelyking met die kontrole-stam. Die transformante wat die KoA-ligases uitgedruk het, het die pkumaarsuur vinniger benut as wat die kontrole dit gedoen het, alhoewel dit nie moontlik was om vas te stel of o-kurnarotel-Kos, geproduseer is nie. Met die essai-kondisies wat gebruik is, is geen resveratroI geproduseer nie. Die resultate het daarop gedui dat die gis nie daartoe in staat is om aktiewe resveratrol-sintase, wat nodig is vir die katalise van die finale reaksie in die produksie van resveratrol, te produseer nie. Naomsettingsmodifikasies van die heteroloe protelen in die gis, soos oor-glikosilasie en disulfiedvorming, is aangewys as die moontlike rede vir die gebrek aan ensiemaktiwiteit. Dit stel In opwindende veld vir verdere navorsing voor, naamlik die ontwikkeling van biotegnologiese middele met die vermoe om die produksie van aktiewe heteroloe protelene in gis te verhoog.

Orientador: Marcia Regina Braga / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-09T08:23:11Z (GMT). No. of bitstreams: 1 Kretzschmar_FernandadosSantos_M.pdf: 1298329 bytes, checksum: ea1fc8a628a790dbf39de684ebe6192d (MD5) Previous issue date: 2007 / Resumo: Plântulas de soja (Glycine max L. Merr), crescidas sob alta concentração de CO2 em sistema de câmaras de topo aberto apresentam incremento na fotossíntese e ganhos de produtividade, podendo alterar a produção de metabólitos secundários de importância farmacológica. Este trabalho teve como objetivo analisar a síntese de flavonas, isoflavonas e pterocarpanos em plântulas de soja (IAC-18, resistente ao fungo causador do cancro da haste Diaporthe phaseolorum f. sp. meridionalis), cultivadas em atmosfera de 380 e 760 mmol mol-1 de CO2 e estimulada por diferentes eliciadores bióticos e abióticos. Fragmentos do b-glucano de Phytophthora megasperma, autoclavados de esporos de D. phaseolorum (Dpm) e moléculas doadoras de óxido nítrico (GSNO e SNP) foram utilizados como eliciadores. Os ensaios foram feitos aplicando-se os eliciadores sobre cotilédones destacados de plântulas de soja com 9 dias de idade (estádio VC). A exposição à 760 mmol mol-1 de CO2 estimulou a fotossíntese, aumentou a área e a massa fresca de cotilédones e folhas e resultou em incremento na produção de coumestrol, daidzeína, genisteína, luteolina e apigenina induzidas principalmente por SNP. Para gliceolinas e daidzina, o efeito estimulador do CO2 foi observado por indução apenas com o b- glucano. Parâmetros bioquímicos relativos aos carboidratos solúveis e estruturais das plântulas de soja também mostraram diferenças significativas entre os dois tratamentos com CO2. Os resultados obtidos reforçam a sugestão de que o incremento na disponibilidade de carbono pode modificar as defesas induzidas em soja contra patógenos, porém, essas alterações ocorrem em metabólitos específicos e dependem do eliciador utilizado / Abstract: Soybean seedlings (Glycine max L. Merr) grown in open top chambers under high CO2 concentrations have shown photosynthetic increment and increase in productivity, which in turn may modify the productio n of secondary metabolites with farmacological importance. The aim of this work was to analyze the synthesis of flavones, isoflavones and pterocarpans in soybean seedlings (IAC-18, a cultivar resistant to the causal agent of the stem canker disease Diaphorthe phaseolorum f. sp. Meridionalis), kept under 380 and 760 mmol mol-1 CO2 atmospheres stimulated by biotic and abiotic elicitors. The b-glucan from mycelial walls of Phythophytora megasperma, autoclaved espores of D. phaseolorum (Dpm) and the NO donors, GSNO and SNP, were used as elicitors. The assays were performed by applying the elicitors on detached cotyledons from 9 days old soybean seedlings (VC stage). The exposition to 760 mmol mol-1 of CO2 stimulated photosynthesis, increased the area and fresh mass of leaves and cotyledons, and raised the production of coumestrol, daidzein, genistein, luteolin and apigenin, mainly induced by SNP. For glyceollins and daidzin the CO2 stimulatory effect was observed only by the induction with the b-glucan. Biochemical parameters related to soluble and structural carbohydrates from soybean seedlings also showed significant differences between the two CO2 treatments. These results strengthen the suggestion that the increment in the carbon availability may modify the inducible defenses in soybean against pathogens. However, these alterations occur in specific metabolites and depend on the elicitor / Mestrado / Biologia Celular / Mestre em Biologia Celular e Estrutural

3-Hydroxy-3-methylglutaryl CoA reductase (HMGR, EC 1.1.1.34) catalyzes the reaction from hydroxymethylglutaryl CoA to mevalonate in the isoprenoid pathway. In solanaceous plants, one class of endproducts of the pathway are sesquiterpenoid phytoalexins, antibiotic compounds produced by plants in response to pathogens. We are interested in the role of the defense-inducible isoforms of HMGR in phytoalexin production and disease resistance. Transgenic tobacco, constitutively expressing the defense-inducible tomato hmgr isogene, hmg2, showed fewer and smaller lesions following tobacco mosaic virus (TMV) inoculation. There is little evidence of phytoalexins acting directly against viruses, but they may reduce the spread of viruses as part of the hypersensitive response resulting in death of the host cell. Transmission electron microscopy of leaf cells of the transgenic plants revealed a larger volume of cytosol and accumulation of electron-dense inclusion bodies within the vacuoles. No structures resembling crystalloid ER or karmellae, caused by overexpression of hmgr in mammalian or yeast cells, respectively, were observed. Similar inclusion bodies were found in the vacuoles of wild-type tobacco leaf cells adjacent to necrotic cells in a TMV lesion. Tobacco expressing a truncated (membrane domain) form of hmg2 did not show enhanced resistance to TMV or any ultrastructural changes, indicating the importance of catalytically active HMG2 in mediating these changes. Sesquiterpene cyclase (a key branch point enzyme controlling sesquiterpene phytoalexin biosynthesis) was not induced and the amount of capsidiol, the tobacco phytoalexin, was not elevated by expression of hmg2. After TMV-inoculation, HMGR activity and the amount of capsidiol were higher in the wild-type than in the transgenic plants. Consequently, the enhanced resistance to TMV was not due to constitutive capsidiol production. The transgenic plants may have been able to produce sesquiterpenoid phytoalexins faster due to constitutive hmg2- expression and restricted the spread of the virus earlier, so that only a few cells were sacrificed. The subcellular localization of the defense-specific HMG2 isoform was determined by tagging tomato hmg2 with a c-myc epitope, and constitutively expressing the construct in transgenic tobacco plants. In non-induced leaves, MYC-HMG2 was found localized in small clusters associated with the ER. In TMV-inoculated leaves MYC-HMG2 co-localized with sesquiterpene cyclase to the vacuolar inclusion bodies suggesting that they may contain a defense-induced, membrane-associated multienzyme complex dedicated to sesquiterpene production. Our results support the hypothesis of the multibranched plant isoprenoid pathway being partly regulated by pathway partitioning. / Ph. D.

Lipid oxidation is one of the leading causes of food quality degradation. Manufacturers typically add antioxidants or purge a product's package of oxygen to inhibit oxidation and the resulting off-flavors. Synthetic antioxidants (e.g. BHT, BHA) and some natural antioxidants (e.g. α-tocopherol) have found widespread use in this application. Unfortunately, the public views synthetic additives in a negative light and the current natural antioxidants have been unable to match the protection afforded by the synthetic antioxidants. The search for underutilized and natural antioxidants has led scientists to investigate many different plant-based extracts for use in food and in the treatment and prevention of disease. The objectives of this research were (1) to use ORAChromatography to identify peanut root extract fractions with high antioxidant capacity, (2) identification of compounds in peanut root extracts using HPLC and mass spectrometry, (3) test for the presence of aflatoxins in the extracts, (4) test peanut root extract in food model system for oxidation reduction capabilities, and (5) Testing peanut root extract's ability to decrease protein oxidation in cell culture. Crude peanut root extracts have high antioxidant activities that do not vary by cultivar. The ORAC activities of the peanut root fractions separated by HPLC with a C18 column varied (600.3 – 6564.4 μM TE/g dry extract), as did the total phenolic contents (23.1 – 79.6 mg GAE/g dry extract). Peanut root fractions had aflatoxins contamination well above the 20 ppb limit. Peanut root extracts and the known antioxidants tested were found to have no significant effect in inhibiting oxidation of peanut paste or HBMEC. Peanut root extracts were not shown to have any positive effects, but further research is necessary to eliminate peanut root extracts as a possible food ingredient and health supplement. / Ph. D.

Phytoalexins and phytoanticipins are antimicrobial natural products involved in plant defence pathways against plant pathogens and other stresses. Most cruciferous phytoalexins are indole containing compounds with various side chains (dithiocarbamates, isothiocyanate, isonitrile, acetonitriles etc.). Many phytoanticipins of crucifers are glucosinolates and their metabolites, which have diverse structures and precursors, including aliphatic, phenyl or indolyl containing amino acids. Indole glucosinolates are derived from tryptophan, which is also a biosynthetic precursor to cruciferous phytoalexins, however the biosynthetic relationship between cruciferous phytoalexins and indole glucosinolates has not been clarified. In this work, investigation of antifungal metabolites from wild crucifers, synthesis of antifungal metabolites and potential perdeuterated biosynthetic precursors, biosynthesis of metabolites of salt cress and that of rutabaga will be described. Investigation of the wild crucifers Brassica tournefortii, Crambe abyssinica, Diplotaxis tenuifolia and Diplotaxis tenuisiliqua for production of elicited antifungal metabolites, resulted in the discovery of a new phytoalexin, 1ꞌ,4ꞌ-dimethoxyindolyl-3ꞌ-acetonitrile, from D. tenuisiliqua. 1ꞌ,4ꞌ-dimethoxyindolyl-3ꞌ-acetonitrile is the first dimethoxy substituted phytoalexin with strong antifungal activity against plant fungal pathogens. The remaining plant species produced known phytoalexins which were initially discovered in wild and cultivated species; all of them produced arvelexin. A novel phytoalexin isocyalexin A, was isolated from rutabaga roots irradiated with UV-light; this is the first isocyanide of plant origin. The second section of the thesis deals with the biosynthesis of metabolites of salt cress (T. salsuginea) and their biosynthetic relationships with indole glucosinolates. In that regard, non-isotopically labeled compounds and perdeuterated biosynthetic intermediates such as [2,2,4ꞌ,5ꞌ,6ꞌ,7ꞌ-2H6]glucobrassicin, [2H3CS;4ꞌ,5ꞌ,6ꞌ,7ꞌ-2H4]-1ꞌ-methoxybrassinin, L-[2ꞌ,4ꞌ,5ꞌ,6ꞌ,7ꞌ-2H5]tryptophan, [2H3CO]-1ꞌ-methoxyindolyl-3ꞌ-acetaldoxime, L-[2H3CS]methionine, [4ꞌ,5ꞌ,6ꞌ,7ꞌ-2H4]brassinin and 1ꞌ-methoxy-2ꞌ-methylbrassinin were administered to salt cress leaves. For the first time, the biosynthetic relationship between indole glucosinolates and cruciferous phytoalexins was established. Intact incorporations of hexadeuterated glucobrassicin ([2,2,4ꞌ,5ꞌ,6ꞌ,7ꞌ-2H6]glucobrassicin) into wasalexins A, B and biswasalexins A1 and A2 were observed. Based on the feeding experiment results, for the first time a biosynthetic route that includes both indole glucosinolates (glucobrassicin and 1ꞌ-methoxyglucobrassicin) and 1ꞌ-methoxybrassinin was proposed. The third section of the thesis is about biosynthesis of metabolites of rutabaga (Brassica napus). Rutabaga produces phytoalexins that differ on their side chains. Biosynthetic origin of their side chains was investigated by administering fully labeled tryptophan (L-[U-13C11,U-15N2]Trp) and other perdeuterated precursors to rutabaga roots which revealed that the carbon and nitrogen atoms of cyclobrassinin, rapalexin A, isocyalexin A and spirobrassinin are fully derived from tryptophan, and also both rapalexin A and isocyalexin A incorporated deuterium from glucobrassicin. [4',5',6',7'-2H4]-4'-Methoxybrassinin was incorporated into 4ꞌ-methoxycyclobrassinin and 4ꞌ-methoxydehydrocyclobrassinin but not into rapalexin A, isocyalexin A and isalexin. The biosynthetic pathway that leads to isalexin, rapalexin A and isocyalexin A was further investigated using perdeuterated biosynthetic precursors such as (R,S)-[2H3CO,5',6',7'-2H3]-4'-methoxyindolyl-3'-glycine, [2H3CO,5',6',7'-2H3]-4'-methoxyindole-3'-carboxaldehyde oxime, [2H3CO,5',6',7'-2H3]desulfoglucorapassicin and etc. It has been confirmed that the pathway involves series of rearrangements that allow transformation of side chain of tryptophan into the side chains of rapalexin A and isocyalexin A without any degradations. In conclusion, cruciferous phytoalexins are derived from glucobrassicin which is a precursor for 1ꞌ- and 4ꞌ-methoxyglucobrassicins. 1-Methoxylated phytoalexins are biosynthesized through 1ꞌ-methoxyglucobrassicin via 1ꞌ-methoxybrassinin. Similarly, 4-methoxy phytoalexins are derived from 4ꞌ-methoxyglucobrassicin through two distinct pathways: via 4ꞌ-methoxybrassinin and 4ꞌ-methoxyindolyl-3ꞌ-glycine.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniversitet, 2010. / Härtill 4 uppsatser.

Made available in DSpace on 2017-07-10T17:40:49Z (GMT). No. of bitstreams: 1 Cristiane_Claudia_Meinerz.pdf: 1140657 bytes, checksum: 515f23cafb30196ea1e4641ed2debc7d (MD5) Previous issue date: 2013-08-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Induced resistance involves the activation of latent defense mechanisms existing in plants in response to treatment with biotic or abiotic agents. The use of plant extracts in order to induce resistance mechanisms is an attractive alternative to chemical control, however, these extracts may occur the presence of inducer, as well ass the presence of suppressor. This study aimed to evaluate biochemical, physiological and growth of sorghum (Sorghum bicolor L.) treated with extracts of Rosmarinus officinalis, Curcuma longa and Pycnoporus sanguineus. It was evaluated the induction of phytoalexins deoxiantocianidinas, peroxidase, polyphenol oxidase, phenylalanine ammonia lyase, β-1,3 glucanase and chitinase, carbon metabolism (photosynthesis and respiration) and growth of sorghum plants. Mesocotyls sorghum were treated with the fungal and plant extracts, and acibenzolar-S-methyl (ASM) (125 mg L-1 elicitor would like reference) and distilled water. Sorghum seedlings were treated with the inducers and at 24, 48, 96 and 144 hours samples were taken for analyzes of defense enzymes. Evaluations of gas exchange were conducted periodically over 7 days with three days interval of application of foliar treatments. Were determined rate of net CO2 assimilation (A, CO2 mol m-2s-1), stomatal conductance (gs mmol H2O m-2s-1), sweating (E, H2O mmol m-2s-1) efficiency Water use (U.S. mol m-2s-1) and intrinsic efficiency of the use of water (EIUA, mol m-2s-1). For growth analysis, carried out 120 days after sowing, the parameters evaluated were: fresh leaves and roots, dry weight of leaves and roots and root volume. The parameters for production analysis were the number of panicle, seed number, mean grain mass and total production. Biotic inducers rosemary, turmeric and Pycnoporus sanguineus induced phytoalexins in mesocotyls and biochemical activities in different cultivars of sorghum, may note that the results reveal an important target for the action of elicitors in these extracts. Overall, rosemary extract caused increase in peroxidase, polyphenol oxidase and phenylalanine ammonia lyase activities, the turmeric extract induced phenylalanine ammonia-lyase activity and the extract of P. sanguineus polyphenol oxidase and β-1,3 glucanase activities. ASM interfere with the metabolism of BRS 610 sorghum in relation to the efficiency of water use (U.S.) and intrinsic efficiency of water use (EIUA), without interfering with productivity, improving the quality of production and improving markedly the number of panicle, panicle, grain number and grain weight. The fungal and plant extracts did not affect these parameters. It was possible to induce defense mechanisms in sorghum by application of extracts of rosemary, turmeric and P. sanguineus, which may allow the obtention of new molecules, and the development of alternative methods for controlling plant diseases / A indução de resistência envolve a ativação de mecanismos de defesa latentes existentes nas plantas em resposta ao tratamento com agentes bióticos ou abióticos. A aplicação de extratos vegetais visando à indução de mecanismos de resistência é uma alternativa interessante ao controle químico, entretanto, nestes extratos pode ocorrer além da presença de indutores, a presença de supressores. Este trabalho teve por objetivo avaliar aspectos bioquímicos, fisiológico e de crescimento de sorgo (Sorghum bicolor L.) tratado com extratos de Rosmarinus officinalis, Curcuma longa e Pycnoporus sanguineus. Foram avaliados a indução de fitoalexinas deoxiantocianidinas, enzimas peroxidase, polifenoloxidase, fenilalanina amônia-liase, β-1,3 glucanase e quitinase, metabolismo de carbono (fotossíntese e respiração) e crescimento de plantas de sorgo. Mesocótilos de sorgo foram tratados com os extratos vegetais e fúngico, além de acibenzolar-S-metil (ASM) (125 mg L-1 do i.a. como elicitor de referência) e água destilada. Plântulas de sorgo foram tratadas com os indutores e às 24, 48, 96 e 144 horas foram retiradas amostras para as análises das enzimas de defesa. As avaliações de trocas gasosas foram realizadas periodicamente no período de 7 dias, com três dias de intervalo da aplicação dos tratamentos via foliar. Foram determinados: taxas de assimilação líquida de CO2 (A, μmol CO2 m-2s-1), condutância estomática (gs, mmol H2O m-2s-1), transpiração (E, mmol H2O m-2s-1), eficiência do uso de água (EUA, mol m-2s-1) e eficiência intrínseca do uso de água (EIUA, mol m-2s-1). Para análise de crescimento, realizada 120 dias após a semeadura, os parâmetros avaliados foram: massa fresca das folhas e raízes; massa seca das folhas e raízes e volume de raiz. Os parâmetros avaliados na análise de produção foram: número de panícula, número de sementes; massa média de grão e produção total. Os indutores bióticos alecrim, cúrcuma e Pycnoporus sanguineus induziram fitoalexinas em mesocótilos e atividades bioquímicas nas diferentes cultivares de sorgo, podendo ressaltar que os resultados revelam um importante alvo de ação de elicitores presentes nesses extratos. De forma geral, o extrato de alecrim causou incremento na atididade de peroxidase, polifenoloxidase e fenilalanina amônia-liase; o extrato de cúrcuma induziu a atividade de fenilalanina amônia-liase e o extrato de P. sanguineus as atividades de polifenoloxidase e β-1,3 glucanase. O indutor ASM interferiu no metabolismo da cultivar BRS 610 de sorgo em relação à eficiência do uso da água (EUA) e eficiência intrínseca do uso da água (EIUA), sem interferir na produtividade, melhorando a qualidade da produção e melhorando acentuadamente o número de panícula, massa de panículas, número de grãos e massa de grãos. Os extratos vegetais e fúngico não interferiram nesses parâmetros. Foi possível induzir mecanismos de defesa em sorgo pela aplicação dos extratos de alecrim, cúrcuma e P. sanguineus, o que pode permitir a obtenção de novas moléculas e o desenvolvimento de métodos alternativos para controle de doenças em plantas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Phenolic compounds in plants have attracted considerable attention during the last decade due to their contribution to human health in reduce the risk of chronic diseases. The grape is one of the largest sources of these substances and like other plants, the synthesis of these compounds is usually associated with defense responses against stress factors, also called elicitors. More recently, ultrasound has been studied as possible abiotic elicitors of secondary metabolites due to mechanical stress and microstreaming induced by acoustic cavitation. Thus, this work aimed evaluate the application of different power densities (53 and 113 W cm-2) and exposure times (1, 5 and 10 minutes) to ultrasound in Isabel and Cabernet Sauvignon grapes about the effects on total polyphenols of juices made from this two cultivars. The samples were also subjected to the determination of total anthocyanins, tannins, total soluble solids, total acidity, pH and sensory evaluation. The Isabel cultivar showed more significant results in response to ultrasound, an increase of up to 83% in the levels of total polyphenols of juice, as well as significant increase in the content of total anthocyanins and tannins. These results were also accompanied by an increase in total soluble solids and total acidity of the juices. The application of ultrasound emphasized color, odor and taste of the Isabel grape juice, and the sonicated treatments were preferred by tasters. About Cabernet Sauvignon cultivar, it only showed a little variation in the most parameters. Power density and exposure time to ultrasound influenced the most of parameters evaluated in juices regarding to degree of response to sonication. Treatment with 5 and 10 min of exposure to ultrasound and power density of 113 W cm-2, is the combination that proved more effective for the elicitation of phenolic compounds by activation of plant secondary metabolism, improving the quality of the Isabel grape juice. / Compostos fenólicos em plantas têm atraído grande atenção durante a última década devido à sua contribuição para a saúde humana, podendo reduzir os riscos de doenças crônicas. A uva é uma das maiores fontes dessas substâncias e assim como os demais vegetais, tem a síntese desses compostos geralmente associada a respostas de defesa contra fatores de estresse, também chamados elicitores. Mais recentemente, o ultrassom vem sendo estudado como possível elicitor abiótico de metabólitos secundários devido a estresse mecânico e microagitação induzidos por cavitação acústica. Dessa forma, este trabalho foi conduzido com o intuito de avaliar a aplicação de diferentes densidades de potência (53 e 113 W cm-2) e tempos de exposição (1, 5 e 10 minutos) ao ultrassom em uvas Isabel e Cabernet Sauvignon quanto aos efeitos sobre os polifenóis totais dos sucos elaborados com as duas cultivares. As amostras também foram submetidas à determinação de antocianinas totais, taninos, sólidos solúveis totais, acidez total, pH e análise sensorial. A cultivar Isabel mostrou resultados mais significativos em resposta ao ultrassom, com elevação de até 83% nos níveis de polifenóis totais do suco, bem como, importante aumento no conteúdo de antocianinas totais e taninos. Estes resultados também foram acompanhados por um aumento nos sólidos solúveis totais e acidez total dos sucos. A aplicação do ultrassom acentuou cor, odor e sabor dos sucos de uvas Isabel, sendo os tratamentos sonicados os preferidos pelos provadores. Quanto a cultivar Cabernet Sauvignon, esta somente apresentou pequena variação na maioria dos parâmetros analisados. A densidade de potência e tempo de exposição ao ultrassom influenciaram a maioria dos parâmetros avaliados nos sucos quanto ao grau de resposta à sonicação. Tratamentos com 5 e 10 min de exposição ao ultrassom, com densidade de potência de 113 W cm-2 mostraram ser a combinação mais efetiva para a elicitação de compostos fenólicos mediante ativação do metabolismo secundário da planta, melhorando a qualidade dos sucos de uva Isabel.