Submitted by DOMINGOS DA COSTA FERREIRA JÚNIOR (junior.domingos@uol.com.br) on 2018-04-27T12:27:20Z No. of bitstreams: 1 Dissertação - Domingos Ferreira.pdf: 1159586 bytes, checksum: 8338f8062aacebc38ac35fa429710de0 (MD5) / Approved for entry into archive by Alexandra Maria Donadon Lusser Segali null (alexmar@fcav.unesp.br) on 2018-05-02T19:01:02Z (GMT) No. of bitstreams: 1 ferreirajunior_dc_me_jabo.pdf: 1159586 bytes, checksum: 8338f8062aacebc38ac35fa429710de0 (MD5) / Made available in DSpace on 2018-05-02T19:01:02Z (GMT). No. of bitstreams: 1 ferreirajunior_dc_me_jabo.pdf: 1159586 bytes, checksum: 8338f8062aacebc38ac35fa429710de0 (MD5) Previous issue date: 2018-03-23 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Muitos estudos apontam que o ácido salicílico (AS) está envolvido na adaptação de plantas a estresses abióticos. Entretanto, pouco se sabe sobre a ação deste hormônio na síntese de importantes metabólitos secundários em condições de estresse, como a lignina. Para tanto, foram estudados neste trabalho os efeitos de AS exógeno no crescimento, lignificação, metabolismo antioxidativo, acúmulo de osmólitos compatíveis e acúmulo de Na+ e macronutrientes em folhas de milho sob concentrações crescentes de NaCl. O delineamento experimental utilizado foi o inteiramente casualizado em esquema fatorial 2x4, representado pelas concentrações de AS (0,0 e 0,5 mM) e concentrações de NaCl (0, 50, 100 e 150 mM). As plantas foram submetidas aos tratamentos no estádio fenológico V4 (quatro folhas completamente desenvolvidas), enquanto que as avaliações foram realizadas no estádio V6 (seis folhas completamente desenvolvidas). Foram avaliados os seguintes parâmetros na parte aérea: área foliar, massa seca, teor de lignina, peroxidação lipídica, teor de peróxido de hidrogênio (H2O2), atividade enzimática da superóxido dismutase (SOD) e catalase (CAT), teor de prolina (Pro) e glicina betaína, relação Na+/K+ e teor de macronutrientes (N, P, Ca, Mg, S). O estresse salino reduziu o crescimento da parte aérea da planta, além de induzir maior acúmulo de Pro e GB, peroxidação lipídica, atividade da CAT e lignificação foliar. A adição de AS à solução nutritiva atenuou o efeito da salinidade sobre o crescimento vegetal até a concentração de 100 mM de NaCl, o que pode estar relacionado à maior lignificação, aumento na atividade da SOD e teores de Pro e H2O2, maior teor de N e Ca, além de reduções nos níveis foliares de Na+ e peroxidação de lipídios. Dessa forma, conclui-se que o AS exógeno atenua os efeitos deletérios de estresse salino baixo e moderado por três vias: maior lignificação foliar, o que pode se relacionar à maior produção de H2O2; menor peroxidação lipídica, relacionada à maior atividade de SOD; e menor teor foliar de Na+, aliado a aumento nos teores de Ca2+ e N. / Several studies demonstrate that salicylic acid (AS) is involved in the adaptation responses of plants to abiotic stresses. However, not much is known about the action of this hormone on the synthesis of important secondary metabolites, as lignin. For this purpose, in this work it was assessed the effects of exogenous application of SA on the growth, lignification, antioxidant metabolism, compatible osmolytes content, and concentration of Na+ and in maize leaves under increasingly NaCl concentrations. It was adopted a completely randomized design and a 2x4 factorial layout, representing SA concentrations (0.0 and 0.5 mM) and NaCl concentrations (0, 50, 100 and 150 mM) in hydroponics. Plants were exposed to the treatments at the V4 phenological stage (with four completely developed leaves), and evaluations were performed at V6 stage (six completely developed leaves). The following parameters were assessed on shoots: leaf area, dry weight, lignin content, lipid peroxidation, enzymatic activity of superoxide dismutase (SOD) and catalase (CAT), proline (Pro) and glycinebetaine (GB) contents, Na+ /K+ ratio and macronutrients concentration (N, P, Ca, Mg and S). Salt stress impaired shoot growth, also inducting higher accumulation of Pro and GB, lipid peroxidation, CAT activity, leaf lignification and also lower content of all evaluated nutrients. The application of AS alleviated the deleterious effects of salinity on maize shoot growth until 100 mM of NaCl, what can be related to an enhancement of SOD activity, lignin, proline and H2O2 contents, higher N and Ca contents, as to lower lipid peroxidation and Na+ content. This way, it is concluded that exogenous AS mitigates the negative effects of low and moderate salt stress on maize through three main ways: higher leaf lignification, which can be correlated with higher H2O2; lower lipid peroxidation, explained by higher SOD activity; and lower Na+ content, followed by increased leaf contents of Ca2+ .

Dans le contexte des changements climatiques globaux, les arbres devront faire face à une atmosphère différente de celle présente actuellement. L'ozone et le CO2 sont deux des principaux gaz dont la hausse de la concentration est préoccupante. Nous avons étudié les effets de l'ozone et du fort CO2, seuls ou combinés, sur la biosynthèse et la teneur de la lignine, l'anatomie et les propriétés du bois de jeunes plants de peupliers (Populus tremula x alba) placés en conditions contrôlées dans des chambres phytotroniques. De plus, ces arbres étaient inclinés afin d'induire la formation de bois de tension. La voie de biosynthèse de la lignine est affectée majoritairement par l'ozone conduisant à une modification de la composition chimique du bois des arbres. L'ozone modifie l'anatomie du bois de tension en diminuant le nombre des vaisseaux formés, l'épaisseur des parois des fibres et augmentant le diamètre du lumen des vaisseaux. Le fort CO2 stimule la croissance des arbres et la production de biomasse mais ne semble pas modifier les propriétés du bois et la synthèse de lignine. L'interaction des deux gaz révèle un effet bénéfique du fort CO2 vis-à-vis des effets néfastes de l'ozone. La présence de fort CO2 limite la baisse du métabolisme des lignines et favorise l'allocation dans la partie moyenne des tiges des plants. Enfin, les propriétés du bois sont modifiées par les différents traitements suggérant une qualité différente pour l'utilisation future du bois. / In the context of global climate change, trees will have to cope with an atmosphere different from actual. Ozone and CO2 are two of the main gas whose increased concentration is worrying. We investigated the effects of ozone and elevated CO2 single or combined on the biosynthesis and content of lignin, wood anatomy and properties of young poplars (Populus tremula x alba) placed in controlled conditions in phytotronic chambers. Moreover, trees were bent to induce tension wood formation. The metabolism of lignin was mainly affected by ozone leading to a change in the chemical composition of wood. Ozone altered wood anatomy by reducing the vessel number, cell wall thickness of fibers and increasing lumen diameter of vessels. Elevated CO2 stimulated radial and height growth, and biomass production, but seemed to have no effect on wood properties and lignin biosynthesis. The interaction of the two gases showed a benefit effect of elevated CO2 against negative effects of ozone. Presence of high CO2 limited lignin metabolism decrease and promoted a better stem allocation of carbon in middle stem of plant. Wood properties were also altered by these treatments suggesting a different quality for the future use of wood.

Aktinidijos (Actinidia kolomikta Maxim.) ūgliai 2013 m. buvo paimti iš Aleksandro Stulginskio Universiteto Pomologiniame sode augančių motininių augalų. Tirtos trys veislės ‘Paukštės Šakarva’, ‘Lankė’ ir ‘Landė’. Siekiant nustatyti genetinius, fiziologinius ir fizinius veiksnius, darančius įtaką margalapės aktinidijos auginių rizogenezei, tirti trijų veislių žalieji auginiai, paimti iš ūglių lignifikacijos pradžioje. Nustatyta, kad ISR augimo reguliatorius didina įsišaknijusių auginių kiekį. IAR augimo reguliatoriaus poveikis žaliesiems auginiams labai panašus kaip ir ISR. Intensyviausiai šaknis regeneravo iš ūglio viršūnės paimti auginiai, kuriems būdingas mažiausias sumedėjimo lygis. Esminę įtaką margalapės aktinidijos žaliųjų auginių rizogenezei darė auginio ilgis. Įrodyta, kad egzistuoja minimalūs auginio, turinčio potencijų rizogenezei, parametrai. Didėjant auginio ilgiui rizogenezės dažnumas didėja. / Actinidia (Actinidia kolomikta Maxim.) shoots in 2013 was cuting Aleksandras Stulginskis University Pomology garden. Were tested three varieties ‘Paukštės Šakarva’, ‘Lankė’ ir ‘Landė’. In order to evaluate genetic, physiologic and physical factors influencing rhizogenesis of soft cuttings of actinidia, cuttings from three cultivars were taken at the beginning of lignification. It was estimated, that the IBA solution, compared with the control slightly increases the yield of cuttings with roots. IAA efficiency is not significantly different from the IBA. Cuttings with the lowest lignification level, wich were taken from terminal shoot part, regenerated roots more intensively. The length of cutting is crucial from the rhizogenesis of actinidia cuttings. Minimal cutting parameters for potential rhizogenesis are shown. Rate of rhizogenesis increase in longer cuttings.

Industrial hemp (Cannabis sativa) is a highly productive crop that is well suited to cultivation in Canada. To better understand the development of bast (phloem) fiber secondary walls and to facilitate reverse genetics screening for improved germplasm, I undertook two sets of microarray experiments. The first compared transcript expression in stem peels at three positions along the length of the stem. The second set of microarray experiments compared transcript expression in adjacent tissue layers along the radial axis of the stem. The transcripts that were enriched in fiber-producing tissues in both studies were consistent with a dynamic program of cell wall deposition. Detailed qRT-PCR analysis of specific lignification genes identified the best targets for reverse genetics. Finally, as a first step towards establishing a virally induced gene silencing (VIGS) system, I identified viruses that produced visual symptoms of infection, although qRT-PCR failed to confirm the infection / Plant Biology

Lignin is the second most abundant biopolymer on earth and is found in the wood (xylem) of vascular land plants. To transport the hydro-mineral sap, xylem forms specialized conduit cells, called tracheary elements (TEs), which are hollow dead cylinders reinforced with lateral secondary cell walls (SCW). These SCWs incorporate lignin to gain mechanical strength, water impermeability and resistance against pathogens. The aim of this thesis is to understand the spatio-temporal deposition of lignin during TE differentiation and the relationship with its neighbouring cells. In vitro TE differentiating cell cultures of Zinnia elegans and Arabidopsis thaliana are ideal tools to study this process: cells differentiate simultaneously into 30-50% TEs while the rest remain parenchymatic (non-TEs). Live-cell imaging of such TEs indicated that lignification occurs after programmed cell death (PCD), in a non-cell autonomous manner, in which the non-TEs provide the lignin monomers. This thesis confirms that lignification occurs and continues long after TE PCD in both in vitro TE cultures and whole plants using biochemical, pharmacological and cytological methods. The cooperative supply of lignin monomers by the non-TEs was demonstrated by using Zinnia and Arabidopsis in vitro TE cultures. Inhibitor experiments revealed further that the non-TEs supply reactive oxygen species (ROS) to TEs and that ROS are required for TE post-mortem lignification. Characterization of the non-TEs showed an enlarged nucleus with increased DNA content, thus indicating that non-TEs are in fact endoreplicated xylem parenchyma cells (XP). The cooperative lignification was confirmed in whole plants by using knock-out mutants in a lignin monomer synthesis gene, which exhibit reduced TE lignification. The XP specific complementation of these mutants led to nearly completely rescuing the TE lignin reduction. Using microscopic techniques, the spatial distribution of lignin was analyzed in TEs from in vitro cultures and whole plants, revealing that lignification is restricted to TE SCWs in both protoxylem and metaxylem. These specific deposition domains were established by phenoloxidases, i.e. laccases localized to SCWs and peroxidases, present in SCWs and the apoplastic space. Laccases were cell-autonomously produced by developing TEs, indicating that the deposition domains are defined before PCD. Altogether, these results highlight that the hydro-mineral sap transport through TEs is enabled by the spatially and temporally controlled lignification of the SCW. Lignification occurs post-mortem by the supply of monomers and ROS from neighbouring XP cells and is restricted to specific deposition domains, defined by the pre-mortem sequestration of phenoloxidases.

No description available.

Diss. (sammanfattning) Umeå : Sveriges lantbruksuniv., 2003. / Härtill 4 uppsatser.

No description available.

Made available in DSpace on 2016-04-28T14:56:20Z (GMT). No. of bitstreams: 1 Desiane Amaral de Deus.pdf: 1202162 bytes, checksum: 1428622ab0c470123554489695966980 (MD5) Previous issue date: 2010-02-26 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Wood is the fifth most consumed product on the world market and has the expectation of consumption growth of 20% for the next decade. Their structural constitution is formed by cellulose, hemicellulose and lignin. Woody plants, in general, have a high lignin content, reaching values above 35% compared to its dry weight. This research aimed to explore the process of lignification in callus culture obtained from Eucalyptus grandis, E. urophylla hybrid E. urograndis and species Lophanthera lactescens Ducke and monitor this process in plants of L. lactescens cultured in vitro. The work is divided in two chapters. The first is related to the species L. lactescens and deals with the determination of a protocol for callus induction and evaluation of the process of lignification in callus and in roots and stems of plants grown in vitro. The process of lignification in plants was accompanied by anatomical characterization. The second chapter, referring to two species of Eucalyptus and the hybrid is the establishment of protocol for callus induction and assessment of the production of lignin in callus produced from different types of explants. To evaluate the process of lignification histochemical tests were made and studies of bright field microscopy, fluorescence microscopy and infrared spectrometry. The best protocol for callus induction in L. lactescens was achieved on MS medium + 9.06 mM 2,4 D. Callus from different explant sources evaluated by infrared spectroscopy showed lignin guaiacyl and syringyl type. Through the microscope and infrared spectroscopy was possible to verify that the lignification in plant L. lactescens in vitro starts at the corners of cells, tissues from young and that plants whose growth was limited by the container germination showed the occurrence of gelatinous fibers. For species of Eucalyptus, the protocol that induced a higher production of callus was MS protocol + 10 mM of 2,4-D + 2.5 mM kinetin + 20 gL-1 sucrose. The species E. urophylla callus showed larger and more friable. Callus from different sources of explants were also evaluated at the infrared signals indicative of the presence of lignin guaiacyl and syringyl type. / A madeira ? o quinto produto mais consumido no mercado mundial e apresenta expectativa de crescimento de consumo de 20% para a pr?xima d?cada. Sua constitui??o estrutural ? formada por celulose, hemicelulose e lignina. Plantas lenhosas, de maneira geral, possuem alto teor de lignina, podendo alcan?ar valores superiores a 35% em rela??o ao seu peso seco. Esta pesquisa teve o objetivo de estudar o processo de lignifica??o em cultura de calos obtidas das esp?cies Eucalyptus grandis, E. urophylla, do h?brido E. urograndis e da esp?cie Lophanthera lactescens Ducke e acompanhar esse processo em plantas de L. lactescens cultivadas in vitro. O trabalho est? dividido em dois cap?tulos. O primeiro ? referente ? esp?cie L. lactescens e trata da determina??o de um protocolo para indu??o da calog?nese e avalia??o do processo de lignifica??o nos calos e em ra?zes e caules de plantas cultivadas in vitro. O processo de lignifica??o nas plantas foi acompanhado atrav?s de caracteriza??o anat?mica. O segundo cap?tulo, referente ?s duas esp?cies de Eucalyptus e o h?brido trata do estabelecimento de protocolo para indu??o da calog?nese e avalia??o da produ??o de lignina nos calos produzidos a partir de diferentes tipos de explantes. Para avalia??o do processo de lignifica??o foram realizados testes histoqu?micos e estudos de microscopia de campo claro, fluoresc?ncia, espectrometria e microscopia no infravermelho. O melhor protocolo de indu??o da calog?nese em L. lactescens foi alcan?ado em meio MS + 9,06 ?M 2,4-D. Os calos oriundos de diferentes fontes de explante avaliados pela espectrometria de infravermelho apresentaram lignina do tipo guaiac?lica e siring?lica. Atrav?s da microscopia e espectrometria de infravermelho foi poss?vel verificar que a lignifica??o em planta de L. lactescens cultivadas in vitro inicia-se nos ?ngulos das c?lulas, desde os tecidos mais jovens e que plantas que tiveram crescimento limitado pelo recipiente de germina??o apresentaram a ocorr?ncia de fibras gelatinosas. Para as esp?cies de Eucalyptus, o protocolo que induziu uma maior produ??o de calos foi o protocolo MS + 10 ?M de 2,4-D, + 2,5 ?M de cinetina + 20 g.L-1 de sacarose. A esp?cie E. urophylla apresentou calos mais fri?veis e maiores. Os calos oriundos de diferentes fontes de explantes avaliados no infravermelho tamb?m apresentaram sinais indicativos da presen?a de lignina do tipo guaiac?lica e siring?lica.

The Arabidopsis chitinase-like1 (Atctl1) mutant, pom1 is compromised in primary cell wall development, resulting in short roots when grown on high sucrose and shortened hypocotyls when grown in darkness. To better understand this phenotype and the evolution of AtCTL1 and its homologue, AtCTL2, we obtained a large number of CTL sequences and determined the phylogenetic relationships among them. Since microarray analysis had suggested a change in auxin response or homeostasis in pom1, I used the auxin reporter DR5::GUS in the pom1 background to assess changes in distribution. To assess whether the biochemical functions of AtCTL1 homologues in Arabidopsis and other plants are conserved, I transformed pom1 with AtCTL2 and CTLs from poplar (Populus trichocarpa x Populus deltoides clone H-11) and from Picea glauca (spruce) and assessed rescue of the pom1 phenotype. To further understand CTL expression and function, Arabidopsis and poplar CTL promoter::GUS fusions were also expressed in Arabidopsis, PopCTL1 overexpressed in Arabidopsis, and CTL expression down regulated in poplar by RNAi. Our results indicate that CTL genes represent an ancient family encoding proteins of conserved biochemical function. In dicots, represented by Arabidopsis and poplar) duplicated CTL genes are differentially expressed in conjunction with primary and secondary cell wall development, respectively. Mutation of these genes results in improperly formed primary walls in certain cell types in the case of AtCTL1, and an impairment in the differentiation of vascular bundles for AtCTL2. Overexpression of PopCTL1 in Arabidopsis seems to over stimulate the differentiation of vascular bundles, and our studies show that auxin distribution is altered in the Atctl1 mutant. Down regulation of PopCTL1 and PopCTL2 in poplar appears to phenocopy aspects of these mutations, resulting in secondary cell walls that appear to have less deposition of lignin and an accelerated production of secondary xylem respectively. While specific biochemical function(s) of CTL genes were not studied, potential functions are discussed.