Thesis (Ph. D.)--University of Wisconsin--Madison, 1959. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 47-50).

Cette étude a pour objectif principal d'évaluer la cohésion et l'adhésion des tissus périphériques du grain de blé natif. Pour ce faire, de nouvelles méthodologies ont été développées. Dans un premier temps, des grains de blé (variétés : Crousty et Tiger) ont été soumis au rayonnement d'un laser impulsionnel (ArF 193 nm , 15 ns). Une interaction photochimique a été observée induisant une ablation progressive des différents tissus périphériques sans modification des tissus sous-jacents. Le taux d'ablation est inversement corrélé à la cohésion des tissus. Par ailleurs, le couplage de l'analyse du plasma émis par spectroscopie (LIBS) et des techniques d'analyse de données multivariées ont permis de suivre l'ablation progressive des tissus in situ et de quantifier l'efficacité d'ionisation de certains minéraux, elle-même reliée à la cohésion tissulaire. Les résultats du taux d'ablation et de l'efficacité d'ionisation ont été cohérents avec les propriétés mécaniques mesurées sur des tissus isolés manuellement. Cette méthode semble prometteuse pour évaluer, de manière indirecte, la cohésion du péricarpe, du testa et de la couche à aleurone sur grain natif, et ouvre la voie au criblage de cultivars. En revanche les interfaces ne sont pas sollicitées. C'est pourquoi, un système mécanique original basé sur le test de pelage en T' (à force ou vitesse imposées) a été ensuite développé afin d'évaluer les énergies nécessaires à la séparation spécifique de ces systèmes multicouches. L'interface ciblée est située entre la couche à aleurone et le reste des enveloppes périphériques sur des échantillons isolés manuellement. Laforce de pelage mesurée à des vitesses lentes traduit l'adhérence entre les tissus. Sa variabilité au sein d'un grain a été reliée à sa morphologie. L'influence de traitements oxydants a été évaluée la cohésion et l'adhésion tissulaire. La cohésion de la couche à aleurone tend à augmenter ainsi que l'adhérence des tissus. Le traitement a modifié le profil des composés phénoliques, sans détecter la formation d'oligomères d'acide férulique. Toutefois l'implication de phénomènes physiques dans l'adhésion tissulaire ne peut être éliminée. Le test de pelage est un outil de choix pour établir des bases physico-chimiques à l'interface des tissus du grain de blé / The aim of this study was to determine the cohesion and adhesion of wheat outer tissues on thenative grain. New methodologies were then developed. First, wheat grains (cultivars : Croustyand Tiger) underwent a pulsed laser (ArF 193 nm , 15 ns). A photochemical interaction wasobserved inducing the gradual ablation of outer tissues without modification of neighbouringlayers. The ablation rate was inversely related the tissue cohesion. Moreover, LIBS used inconjunction with multivariate analysis was an interesting technique to follow tissue gradualablation and to estimate tissue cohesion by the ionization effectiveness. The results of theablation rate and ionization effectiveness were coherent with the mechanical properties measuredusing hand-isolated tissues. This methodology could be appropriate to estimate, even thoughindirectly, the cohesion of the pericarp, the seed coat, and the aleurone layer, directly on thenative grain, and to carry out the screening of cultivars. On the other hand, interface propertieswere not determined. In this manner, a classical T' peel test was developed and adapted in orderto evaluate the adherence of this multilayered system. The studied interface was between thealeurone layer and the other external tissues on hand-isolated samples. Peel force at minimal peelrates could be related to tissue adherence. The variability of this force was related to grainmorphology. The effect of oxidative treatments in the tissue cohesion and adherence wasinvestigated. Using an oxidative treatment, either the cohesion or the adherence of wheat tissuestend to increase. This treatments modified the phenolic profile, without being able to specificallydetect any formation in the ferulic acid oligomerization. However, physical changes at theinterface properties could be neglected. The peel test could be an appropriate methodology tounderstand better the physico-chemical bases at the interface of wheat outer tissues

xx, 277 leaves : ill. ; 26 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.1974) from the Dept. of Plant Physiology, University of Adelaide

Thesis (Ph.D. 1974) from the Dept. of Plant Physiology, University of Adelaide.

Cette étude a pour objectif d'évaluer la relation entre la structure (au niveau physique et / ou moléculaire) de son de blé et de la couche à aleurone et leurs effets santé. En gardant la composition du son et de l'aleurone constante, leur structures ont été modifiés par des traitements mécaniques et / ou enzymatiques de façon à casser leur structure matricielle complexe et d'augmenter la bioaccessibilité des leurs fibres alimentaires et composés phénoliques. La capacité antioxydante des ces fractions a été évaluée par une méthode standard in vitro et par un modèle de digestion gastrique in vitro. La déstructuration physique du son et aleurone par le broyage a augmenté leur surface spécifique conduisant à une plus grande exposition du groupement acide férulique (AF) qui a augmenté leur capacité antioxydante. Le traitement enzymatique réalisée sur aleurone a modifié son organisation moléculaire, qui a largement libéré l'AF des arabinoxylanes (AX). Cette destructuration a apporté une amélioration plus importante sur la capacité antioxydante de l'aleurone que celle mené par le broyage. Comme l'aleurone est riche en AX fermentescibles, les effets de sa structure plus accessible et avec une plus grande dépolymérisation ont été évaluées en utilisant un modèle in vitro en mimant le côlon humain. La déstructuration physique de l'aleurone par le broyage n'a pas amélioré leur pouvoir fermentescible, c'est à dire que le métabolisme de composés phénoliques et de la formation des chaînes courtes d'acides gras ont été comparable à ceux obtenus pour l'aleurone natif. Néanmoins, la dégradation enzymatique de l'aleurone en apportant une plus grande quantité des AX soluble et de l'AF biodisponible a augmenté le métabolisme de l'AF dans le colon dans des métabolites avec propriétés anti-inflammatoires. Une étude in vivo avec des souris sur un régime riche en graisses a été fait pour évaluer le potentiel de l'aleurone physiquement et moléculaire déstructuré pour neutraliser les désordres métaboliques tels que l'obésité, le stress oxydatif et l'inflammation. La déstructuration physique de l'aleurone n'a pas eu d'effet positif sur les désordres métaboliques. La fraction d'aleurone qui a présenté la plus grande quantité d'AX soluble et de l'AF biodisponible a bien réduit l'obésité (gain de poids, l'adiposité et la sécrétion de leptine) et la résistance à l'insuline chez la souris. Par contre, aucune différence significative n'a été observée dans le stress oxydatif et l'inflammation des souris nourries avec des régimes enrichis en aleurone. En conclusion, nous avons démontré que les effets santé de l'aleurone sont clairement liées à l'intégrité de sa structure. Ses effets santé ont été accrues par une modification de sa structure principalement au niveau moléculaire en dégradant ses parois cellulaire pour augmenter la bioaccessibilité et la biodisponibilité des composés nutritionnellement intéressants, tels que l'AX et l'FA. / The objective of this study was to evaluate the relationship between the structure (at physical and/or molecular level) of wheat bran and aleurone and their health effects. Keeping the composition of bran and aleurone constant, their structure was modified by mechanical and/or enzymatic treatments in order to disrupt their complex matrix structure and increase the bioaccessibility of their dietary fibre and phenolic compounds. The antioxidant capacity of the bran and aleurone fractions was evaluated by a standard in vitro test and by an in vitro gastric digestion model. The grinding disrupted the physical structure of bran and aleurone increasing their specific surface leading to a greater exposition of ferulic acid moiety (FA) which increased their antioxidant capacity. Enzymatic treatment performed on aleurone acted on its molecular organisation releasing its FA from arabinoxylans (AX). This destructuration improved the antioxidant capacity of aleurone even more than the one allowed by grinding. As aleurone is rich in highly fermentable AX, the effects of its better accessibility and depolymerisation were evaluated using an in vitro model mimicking the human colon. The physical destructuration of aleurone by grinding did not improve its fermentability, i.e. the colonic metabolism of phenolic compounds and the formation of short-chain fatty acids were similar compared to the native aleurone. Nevertheless, the enzymatic degradation of aleurone produced higher amount of soluble AX and bioavailable FA improving the metabolism of colonic FA in metabolites with anti-inflammatory properties. An in vivo mouse study with a high-fat diet was used to evaluate the potential of physically and molecularly destructured aleurone to counteract the metabolic disorders, such as obesity, oxidative stress and inflammation. The physical destructuration of aleurone did not have any positive effect on the metabolic disorders. The aleurone fraction, which presented the highest level of soluble AX and bioavailable FA, reduced the obesity (body weight gain, adiposity, and leptin secretion) and insulin resistance in mice. But no significant differences were observed in the oxidative stress and inflammation status of mice fed with any of the aleurone-based diets. In conclusion, we demonstrated that the aleurone health effects were clearly linked to the integrity of its structure. Its health effects have been increased by modification of its structure mainly at molecular level by degrading its cell wall to increase the bioaccessibility and bioavailability of nutritionally interesting compounds, such as AX and FA.

Orientador: Paulo Arruda / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-06T21:19:28Z (GMT). No. of bitstreams: 1 Ferreira_NataliaCristinaVerza_D.pdf: 9495810 bytes, checksum: 18cf9ae055a2b9f39de109abc6de469c (MD5) Previous issue date: 2006 / Resumo: O seqüenciamento de ESTs (etiquetas de seqüências expressas) e a sua organização em bancos de dados constituem poderosas ferramentas para identificar genes de interesse expressos em determinados tecidos e/ou tipos celulares. Neste trabalho criou-se um banco de seqüências expressas chamado MAIZESTdb, que contém ESTs de diversos tecidos de milho, porém enriquecido com seqüências provenientes do endosperma de milho em desenvolvimento. O MAIZESTdb contém 227.431 ESTs vindos de mais de 30 órgãos e tecidos de milho diferentes, 30.531 seqüenciados em nosso laboratório a partir de bibliotecas construídas com RNA mensageiro de endosperma. Estas seqüências representam uma grande contribuição na identificação de novos genes expressos no endosperma. A análise deste banco de ESTs possibilitou a identificação de 4.032 transcritos preferencialmente expressos no endosperma, e a sua anotação revelou uma ampla variedade de prováveis genes novos envolvidos no desenvolvimento e no metabolismo do endosperma. O banco MAIZESTdb foi utilizado neste trabalho para a identificação de fatores de transcrição (TFs) expressos no endosperma de milho, e, especialmente, na identificação de fatores preferencialmente expressos no endosperma, que podem desempenhar papéis regulatórios importantes durante a formação da semente. Foram identificados 1.233 TFs expressos em milho, 414 dos quais expressos no endosperma em desenvolvimento. Foram identificados ainda, através de análises in silico, 113 TFs preferencialmente expressos no endosperma, conjunto este que representa 9.2% dos TFs expressos identificados em milho, e que possivelmente contém reguladores importantes dos processos de especificação celular e desenvolvimento do endosperma de milho. Esta é a maior coleção de fatores de transcrição já descrita para este tecido, e representa uma fonte de dados importante para identificação de reguladores dos principais processos relacionados ao desenvolvimento do endosperma, como metabolismo de nitrogênio e carboidratos e controle da massa da semente. Uma das famílias mais representadas entre os TFs preferencialmente expressos no endosperma foi a família NAC de fatores de transcrição. Esta família apresentou 12 membros preferencialmente expressos no endosperma de milho. Um novo membro da família NAC, chamado de EPN-1 (Endosperm Specific NAM 1), teve seu perfil de expressão caracterizado. Sua expressão pode ser detectada desde os 5 DAPs, embora o pico de expressão ocorra entre 20 e 25 DAP, e ele apresenta expressão preferencial no endosperma. O promotor do gene EPN-1 foi clonado, seqüenciado e analisado quanto aos seus possíveis elementos CIS regulatórios; foram encontrados elementos conservados relacionados à endosperma-especificidade, elementos relacionados à regulação por ácido abscísico e giberelinas, e elementos conservados presentes nos promotores de a-amilases, indicando uma possível relação deste gene com o processo de transição entre a maturação e a germinação da semente. Ensaios de expressão transitória com o promotor do gene EPN-1 revelaram que sua expressão está dirigida à camada de aleurona do endosperma de milho, o que constitui mais uma evidência de sua possível função na regulação de genes relacionados aos processos de maturação e germinação da semente / Abstract: The sequencing of ESTs (expressed sequence tags) and its organization in databases constitute powerful tools to identify genes of interest in certain tissues and/or cell types. In this work we have created MAIZESTdb, a database of ESTs expressed in diverse maize tissues. The importance of this database, however, is that it is enriched with sequences from developing maize endosperm. The MAIZESTdb contains 227,431 ESTs coming from more than 30 different maize tissues and organs, 30,531 of which sequenced from endosperm cDNA libraries constructed in our laboratory. These sequences represent a great contribution for the identification of novel genes expressed in endosperm. The analysis of this ESTs database led to the identification of 4,032 transcripts preferentially expressed in the endosperm, and its annotation revealed a great variety of new genes involved in endosperm metabolism and development. The MAIZESTdb was then used to identify transcription factors (TFs) expressed in maize endosperm, and, mainly, in the identification of TFs preferentially expressed in the endosperm. We identified 1,233 TFs expressed in diverse maize tissues, 414 of which expressed in developing endosperm. We also identified, through in silico comparison of transcript abundance and library source, 113 TFs with preferential expression in endosperm, representing 9,2% of the TFs identified in this work. This dataset probably contains important regulators of cellular specification of the endosperm development. This is the biggest TFs collection reported for this tissue, and represents an important source of data for identification of regulators for main processes related to the endosperm development such as nitrogen and carbohydrate metabolism and control of seed mass. One of the most represented families among the TFs preferentially expressed in endosperm was the NAC family of transcription factors. This family presented 12 members with preferential expression in the endosperm. A new member of the NAC family, called EPN-1 (Endosperm Specific NAM 1), was characterized. Its expression / Doutorado / Genetica Vegetal e Melhoramento / Doutor em Genetica e Biologia Molecular

Health benefits related to consumption of whole grains have been attributed in part to phytochemical and micronutrient composition. Understanding the composition, structure and distribution of these components in different cereal grains is of potential importance in aiding the selection of whole grains and their processed fractions for inclusion in the diet, and as ingredients in development of new food products. The aim of this research was to characterise the chemical components in the botanical fractions of yellow corn, barley, wheat. Manual separation, a tedious and laborious technique that yields pure fractions, suitable for compositional analysis, was used to separate whole grains into pericarp, aleurone layer, germ and endosperm fractions. Component identification and quantification of tissue components was accomplished by several techniques. The study also explored the possibility of using spectral characteristics fluorescence intensity values to provide rapid estimates of the concentrations and distribution of ferulic acid (FA), a major phenolic compound in cereal grains. While composition of phenolic acids and carotenoids was similar, the distribution was significantly different (P < 0.05) among cereal types and grain fractions. Phenolic acids were concentrated in pericarp and aleurone fractions, followed by the germ and the endosperm had the lowest levels. Yellow corn exhibited the highest values. Carotenoids, lutein and zeaxanthin were concentrated in the germ and aleurone layer of wheat and barley while in yellow corn it was in the endosperm and aleurone layer. This is the first study to report on carotenoid composition of aleurone fractions. Mineral elements, thiamine and niacin were higher in wheat aleurone than in purple barley and yellow corn aleurone layers. These findings suggest that yellow corn aleurone layers have potential as a functional food ingredient despite the low micronutrient content. A positive, significant correlation (r= 0.421, p < 0.0001) was found between fluorescence intensity values and ferulic acid concentration. Thus, fluorescence intensity profiles are a promising approach for rapid assessment of FA concentration in grain in-situ. This work has provided information that would act as a database for selection of cereal fractions and guide the miller to obtain grain fractions with enriched levels of phytochemicals and micronutrients. / February 2016

Thesis (MScAgric)--Stellenbosch University, 2011. / ENGLISH ABSTRACT: Research into markers for the detection of genetic diversity and cultivar identification has become an important component of the genetic improvement of crops. However, the incorporation of marker assisted selection (MAS) as a tool for the identification and characterization of breeding material has not been fully implemented in the breeding of spring triticale at Stellenbosch University’s Plant Breeding laboratory (SU-PBL). The present study served as a case study in order to achieve this. The first part of the study concerned the detection of genetic diversity in 101 newly sourced triticale cultivars, from a USDA germplasm bank, together with five local control cultivars, in order to identify possible crossing parents. Eight SSR markers, including five derived from rye and three from wheat, and five agronomic characteristics were used to assess diversity. In seedling screening the foreign cultivars showed resistance towards the stem rust isolate used, but were mostly susceptible to the leaf rust isolate. Out of the 8 SSR markers tested, 7 markers were polymorphic and revealed 140 alleles varying from 12 to 26 with an average of 17.5 alleles per locus. The observed polymorphic information content (PIC) value ranged from 0.39 to 0.88 with an average of 0.70, indicative of the good discriminatory ability of the SSR markers. The data revealed that the South African cultivars were genetically closely related to cultivars from the USA and Canada. The second part of the study focused on the introgression of a blue aleurone layer gene (Ba), carried by a wheat cultivar, ‘Cltr1202STR’, and purple pericarp genes (Pp1; Pp3) also carried by a wheat cultivar, ‘Amethyst’, into a triticale background. Unfortunately the introgression of the purple pericarp genes failed. Two lines containing the blue aleurone layer, 11T023 and 11T028, were however successfully created. Molecular typing of these lines with SSR markers were able to show that BC4F1 line 11T023 (Ba) B was genetically similar to the recurrent parent ‘Agbeacon’; and that the BC4F1 11T028 line (Ba) A was closest to the ‘US2007’ recurrent parent. The study illustrated that MAS was a reliable tool for detecting genetic diversity in newly sourced germplasm, and assisted in making a backcross breeding effort more effective. The data generated from MAS could therefore clearly assist in making the SU-PBL breeding program more effective by moving, better informed, decision making toward data based partly on the genotype, thereby minimizing the risks associated with purely phenotypic based decisions. / AFRIKAANSE OPSOMMING: Navorsing rondom die gebruik van merkers vir die bepaling van genetiese-diversiteit en kultivar identifikasie is ‘n toenemend belangriker komponent vir die genetiese verbetering van gewasse. Die inkorporering van merker-bemiddelde-seleksie (MBS) as gereedskap vir die identifikasie en karaktarisering van telingsmateriaal is nog nie ten volle geïmplimenteer in die lente korogtelingsprogram van die Stellenbosch Universiteit Planteteeltlaboratorium (SU-PTL). Die studie het gedien as gevallestudie ten einde dit te bereik. Die eerste gedeelte van die studie het gehandel oor die tipering van die genetiese diversiteit van ‘n 101 kultivars verkry vanaf ‘n USDA kiemplasmabank saam met 5 plaaslike kontroles. Dit was gedien ten einde moontlike kruisings-ouers te kon identifiseer. Agt SSR merkers, insluitend vyf afkomstig van rog en drie vanaf koring, asook vyf agronomiese kenmerke is aangewend om die materiaal se diversiteit te tipeer. Saailingtoetsing is ook gedoen en het aangetoon dat die meeste kultivars weerstandig was vir die stamroes-isolaat, maar nie die blaarroes-isolaat nie. Van die agt SSR merkers getoets het sewe getoon om polimorfies te wees en het ‘n 140 allele gegee wat gewissel het vanaf 12 tot 26 per lokus met ‘n gemiddeld van 17.5. Die waargenome polimorfiese inligtings inhoud (PII) waarde het gewissel vanaf 0.39 tot 0.88 met ‘n gemiddeld van 0.70. Die merkers kon dus suksesvol diskrimineer. Die data het aangetoon dat die Suid-Afrikaanse kultivars genetiese die naaste verwant was aan die kultivars afkomstig vanaf die VSA en Kanada. Die tweede gedeelte van die studie het gefokus op die introgressie van ‘n blou aleuron-laag geen (Ba), afkomstig vanaf die koringkultivar ‘Cltr1202STR’, en twee pers-perikarp gene (Pp1; Pp3), afkomstig vanaf die koringkultivar ‘Amethyst’, na ‘n korog agtergrond. Ongelukkig het die oordrag van die pers-perikarp gene gefaal. Twee lyne wat die blou aleuron- laag bevat, 11T023 en 11T028, is egter suksesvol geskep. Tipering van die lyne met die SSR merkers het aangetoon dat die BC4F1 lyn 11T023 (Ba) B genetiese baie na aan die herhalende ouers ‘Agbeacon’ is en dat die BC4F1 11T028 lyn (Ba) A nader is aan die herhalende ouer ‘US2007’. Die studie het dus geïllustreer dat MBS gebruik kan word as ‘n betroubare manier om genetiese diversiteit te bepaal en by te dra tot die sukses van ‘n terugkruisingsprogram. Die data wat dus voortspruit uit MBS kan dus help om die SU-PTL se telingsprogram te assisteer in die besluitnemingsproses tydens teling deur beter genotipe gebaseerde besluite te neem wat die riskio van fenotipe gebaseerde besluite kan help verminder.

The sensitivity, speed, and reproducibility of modern mass spectrometers enable in-depth new functional looks into the cellular proteome. Thousands of proteins can be detected in a single sample. In Co-Fractionation Mass Spectrometry (CF-MS) method, the input sample is fractionated by any biochemical method of choice. The reduced complexity of each fractionated sample leads to better proteome coverage. The separation profiles provide functional information on the proteins. This application has been used to predict organelle localization based on co-purification with marker proteins. More recently, CF-MS is being used to measure the apparent masses and determine the localization of soluble or membrane-associated protein complexes. This Ph.D. dissertation focuses on the extension of the boundary of CF-MS application to learn how protein complex evolution and protein complex composition have been accomplished. In the first part of this dissertation, the data will be presented on the degree to which variation in protein oligomerization across plant species is present, how proteomics in phylogenetic analysis (phyloproteomics/evolutionary proteomics) helps understand the evolutionary changes, and how oligomerization drives neofunctionalization during plant evolution. The latter part will describe that CF-MS coupled with multiple orthogonal chromatographic separations increases the resolving power of the profiling technique, enabling the composition of protein complexes to be predicted in the subaleurone layers of rice endosperm. Lots of novel protein complexes involved in RNA binding protein, translation, and the tissue-species metabolism will be discussed.