The study on dehydration of frozen saskatoon berries and the need for dried fruits has been strategically identified in the prairies. Our motivation was to find a suitable method for dehydration in order to extend saskatoon berry shelf life for preservation. Microwave, convection and microwave-convection combination drying processes were identified to finish-dry saskatoon berries after osmotic dehydration using sucrose and high fructose corn syrup (HFCS) sugar solutions. Osmotic dehydration removes moisture in small quantities and also introduces solutes into the fruit that acts as a preservative and also reduces the total drying time. <p>Due to the very short harvesting season of saskatoon berries, an accelerated process like microwave combination drying can bring down the moisture to safe storage level, immediately after harvest. Untreated and osmotically dehydrated berries were subjected to convection (control), microwave and microwave-convection combination drying conditions at different product drying temperatures (60, 70 and 80C) until final moisture content was 25% dry basis. A laboratory-scale microwave combination dryer was developed, built with temperature and moisture loss data acquisition systems using LabView 6i software. Thin-layer cross flow dryer was used for convection-only drying and for comparison. <p>Drying kinetics of the drying processes were studied and curve fitting with five empirical equations including Page equation, was carried to determine drying constant, R2 and standard error values. The microwave-combination drying method proved to be the best for drying saskatoon berries. Dehydrated product quality analysis by means of color changes, rehydration ratio measurements and observed structural changes with scanning electron microscope technique were the factors in drying method selection for saskatoon berries.<p> This research was instrumental in the modification and development of a novel drying system for high-moisture agricultural materials. Microwave-convection combination drying at 70oC, yields good results with higher drying rates and better end-product quality.

Thesis (doctoral)--Université de Paris, 1919. / Vol. 2 has title: Le Berry dans l'œuvre de George Sand. Vol. 1 has subtitle: Nohant, 1808-1876. Includes indexes. Includes bibliographical references (v. 1, p. [632]-657; v. 2, p. [356]-366).

Les cisterciens se sont implantés dans de nombreux diocèses au cours des XIIe et XIIIe siècles. Celui de Bourges se singularise de ceux qui l'environnent par la quantité et la précocité de ses fondations. La première explication à ce phénomène se trouve dans l'évidente piété de l'époque, relayée, voire amplifiée, par des archevêques entretenant des relations importantes avec Bernard de Clairvaux. Mais il existe également une véritable "politique" d'implantations, certes gérée par ces derniers, mais sous-tendue par les luttes d'influences auxquelles se livrent les différentes "factions" qui se partagent ce territoire. Il apparaît ainsi nettement que les établissements tiennent un rôle politique aussi bien que religieux. C'est dans ce contexte que le diocèse de Bourges accueille quatorze établissements. Leur étude individuelle a fait surgir de l'ombre certains d'entre eux, totalement ignorés des chercheurs ou en grande partie méconnus. Ainsi, d'un point de vue historique, il a été possible d'affiner les dates de fondation et parfois de préciser l'identité des fondateurs ainsi que leurs motivations. L'étude architecturale, pour sa part, a engendré la restitution des plans des édifices ou tout au moins une hypothèse raisonnable de ceux-ci. Elle a également servi à recadrer les périodes de construction et à identifier l'introduction et l'utilisation de techniques nouvelles. Il en résulte un ensemble cohérent au sein duquel se transmettent les avancées des techniques architecturales et derrière lequel transparaît une influence de l'ordre, cette dernière étant plutôt structurelle que formelle. / The Cistercians settled in numerous dioceses throughout the 12th and 13th centuries. The diocese of Bourges stands alone amongst those around il for the quantity and earliness of its foundations. The first explanation to this phenomenon can be found in the obvious piety during this era, transmitted, if not amplified, by archbishops maintaining links to Bernard de Clairvaux. There also exists, however, a true settlement "policy", managed, it is true, by the archbishops, but intensified by the struggle for influence between the various "factions" sharing this territory. It is therefore clearly apparent that these institutions hold a role as much political as religious. It is in this context that the diocese of Bourges hosts fourteen institutions. Individual study has shed light on some of them, which had been totally ignored by scholars, or had at best been unrecognised. Thus, from a historical point of view, it has been possible to pinpoint the founding dates and at times to reveal the identity of the founding members, as well as what motivated them. For it part, architectural study was the point of origin of the rediscovery of the buildings' plans, or at least a reasonable hypothesis for them. It also helped to establish new time brackets for the construction and to identify the dates of introduction and use of new techniques. A coherent whole therefore emerges, at the heart of which advances in architectural techniques are shared and behind which transpires the influence of the order, more structural than formal.

In this thesis, research starts by questioning Berry curvature dipole's role in electronic properties in solids. Strongly inspired by the recent studies, we discover a more profound interpretation of the Berry curvature dipole. It is demonstrated that the anomalous correction to the electron acceleration is proportional to the Berry curvature dipole and is responsible for the Non-linear Hall effect recently discovered in materials with broken inversion symmetry. This allows uncovering a deeper meaning of the Berry curvature dipole as a non-linear version of the Drude weight that serves as a measurable order parameter for broken inversion symmetry in metals. Later, we introduce the Quantum Rectification Sum Rule in time-reversal invariant materials is derived by showing that the integral over frequency of the rectification conductivity depends solely on the Berry connection and not on the band energies or relaxation rates. In the final part of the thesis, we use the Keldysch-Floquet formalism to obtain non-perturbative predictions of the optical responses in solids, mainly focusing on the clean limit response of systems with broken time-reversal symmetry.

Thesis (MSc)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Grape quality is important for the producer, exporter and the consumer. Consumers judge table grapes according to their size, colour, taste and shelf life. The consumer’s prerequisites will influence the producer. Therefore, it is essential to know how the table grape berry develops so that it can be manipulated, favouring the postharvest quality and shelf life. This study was performed on Prime and Crimson Seedless, both grafted onto Ramsey, in the Paarl district of South Africa. The aim of this study was to describe and quantify table grape berry development and compositional changes taking place throughout growth and ripening. The effect of sugar:acid ratio on postharvest shelf life was also evaluated. To evaluate whether berry size influenced the measured development parameters, three berry sizes were induced for both cultivars by using plant bioregulators such as gibberellic acid (GA3) and forchlorfenuron – synthetic cytokinin (CPPU) or girdling. The following sizes were obtained for Prime: (i) small berries (<20 mm) with no treatment, which acted as the control; (ii) medium berries (20-24 mm) obtained by 15 ppm GA3 application at 8 mm berry size; (iii) large berries (>24 mm) obtained by combination of 15 ppm GA3 and 1 ppm CPPU application at 8 mm berry size. Crimson Seedless berry sizes were as follows: (i) small berries (<18 mm) with no treatment, which acted as the control; (ii) medium berries (18-22 mm) treated with 10 ppm GA3 at 7 mm berry size; (iii) large berries (>22 mm) treated with 10 ppm GA3 and vines were girdled at 7 mm berry size. To evaluate the effect of sugar:acid ratio on postharvest shelf life, grapes were stored for five weeks at -0.5 ˚C and another week at 7.5˚C. The bunches were evaluated for loose berries, browning, soft tissue breakdown, decay and berry split. The following components were analysed for both cultivars to determine changes in berry composition throughout the season: berry fresh weight, total soluble solids (TSS), glucose, fructose, titratable acidity (TA), tartaric acid, malic acid, abscisic acid (ABA) and total phenols. Total and individual anthocyanins were analysed for Crimson Seedless. Differences were obtained for the three berry sizes for both cultivars. Véraison, representing the start of ripening, started at the same time in successive seasons: 21 days after pea size berry (5 mm berry diameter) for Prime and 28 days after pea size berry (5 mm berry diameter) for Crimson Seedless. A lag stage was not observed, at seven day sampling intervals, for either of the cultivars. Components such as TSS, glucose, fructose and TA content per berry were influenced by berry size in either one or in both seasons for both cultivars. Significant changes in component concentration were detected at the start of, or around véraison. Sugar concentrations (TSS) already started to increase for both cultivars before the start of véraison. At véraison, concentrations of glucose, fructose and ABA increased while concentrations of TA, tartaric acid, malic acid and total phenols decreased. Total anthocyanins in Crimson Seedless started to increase one week after véraison commenced. The main anthocyanin found in Crimson Seedless was peonidin-3-glucoside. During ripening a 1:1 glucose:fructose ratio was detected in both cultivars. Prime tartaric:malic acid ratio was lower than Crimson Seedless tartaric:malic acid ratio in both seasons. Tartaric acid was the main organic acid found in Prime, while malic acid was the main organic acid found in Crimson Seedless. No significant differences were found in the postharvest defects between the different berry sizes. However, tendencies for differences were observed which led to the assumption that medium size berries were more prone to loose berries in both cultivars. Large berries showed a higher percentage berry split for both cultivars. Crimson Seedless second harvest date took place 24 hours after rainfall which could have very likely led to the higher percentages berry defects compared to the first season. Greater berry decay was found with later harvest dates for both cultivars. No significant differences were found for the TSS:TA ratio between the three berry sizes for both cultivars. Postharvest defects were therefore found not only to be influenced by TSS:TA ratio but rather by harvest date and packing procedures. Environmental conditions prior to harvest also had an impact on postharvest shelf life. / AFRIKAANSE OPSOMMING: Druif kwaliteit is belangrik vir die produsent, uitvoerder en verbruiker. Tafeldruiwe word gekeur deur die verbruiker volgens grootte, kleur, smaak en raklewe. Die verbruiker se voorkeure sal dus die produsent beïnvloed. Daarom is dit belangrik om te weet hoe tafeldruiwe ontwikkel ten einde korrelsamestelling te manipuleer om na-oes kwaliteit en raklewe te kan bevoordeel. Hierdie studie is uitgevoer op Prime en Crimson Seedless, beide geënt op Ramsey, in die Paarl distrik van Suid Afrika. Die doel van die studie is om vas te stel hoe korrelsamestelling gedurende groei en rypwording verander. Die effek van suiker:suurverhouding op na-oes raklewe is ook geëvalueer. Om te kan meet of korrel grootte die gemete parameter beïnvloed is drie korrelgroottes verkry vir albei kultivars deur die gebruik van plant bioreguleerders, te wete gibbereliensuur (GA3) en sintetiese sitokiniene (CPPU), of ringelering. Die volgende korrelgroottes is verkry vir Prime: (i) klein korrels (<20 mm) d.m.v. geen behandeling, geklassifiseerd as kontrole; (ii) medium korrels (20-24 mm) d.m.v. ‘n 15 dpm GA3 behandeling by 8 mm korrelgrootte; (iii) groot korrels (>24 mm) d.m.v. ‘n kombinasie van 15 dpm GA3 en 1 dpm CPPU by 8 mm korrelgrootte. Crimson Seedless korrelgroottes was soos volg: (i) klein korrels (<18 mm) d.m.v. geen behandeling, wat as kontrole gedien het; (ii) medium korrels (18-22 mm) d.m.v. ‘n 10 dpm GA3 behandeling by 7 mm korrelgrootte; (iii) groot korrels (>22 mm) d.m.v. ‘n 10 dpm GA3 behandeling en gelyktydige ringelering by 7 mm korrelgrootte. Om die effek van suiker:suur verhouding op na-oes houvermoë te kon evalueer was druiwe gestoor vir vyf weke by -0.5˚C en ‘n verdere week by 7˚C. Die trosse is geëvalueer vir loskorrels, verbruining, sagte weefsel afbreek, verval en korrelbars. Die volgende komponente is geanaliseer vir albei kultivars om veranderinge in korrelsamestelling gedurende die seisoen te bepaal: vars korrelgewig, totale oplosbare vaste stowwe (suikerinhoud), glukose, fruktose, titreerbare sure, wynsteensuur, appelsuur, absisiensuur en totale fenole. Die totale en individuele antosianiene is ook vir Crimson Seedless gemeet. Beduidende verskille tussen die drie korrelgroottes vir albei kultivars is verkry. Deurslaan, naamlik die begin van rypwording, het op dieselfde dag in opeenvolgende seisoene plaasgevind: 21 dae na ertjiekorrel grootte (5 mm korrel deursnee) vir Prime en 28 dae na ertjiekorrel grootte (5 mm korrel deursnee) vir Crimson Seedless. In teenstelling met die tipiese korrel ontwikkelingspatroon is ‘n rusfase nie waargeneem by beide kultivars nie. Komponente soos suikerinhoud, glukose, fruktose en titreerbare suur inhoud per korrel is deur korrelgrootte beïnvloed in een of albei seisoene vir beide kultivars. Suiker konsentrasie van albei kultivars het reeds voor deurslaan begin toeneem. By deurslaan het die konsentrasies van glukose, fruktose en absisiensuur inhoud toegeneem, terwyl die konsentraies van titreerbare sure, wynsteensuur, appelsuur en totale fenole gedaal het. Totale antosianiene in Crimson Seedless het ‘n week na deurslaan begin toeneem. Die hoof antosianien in Crimson Seedless is peonidien-3-glukosied. Gedurende rypwording was daar ‘n 1:1 glukose:fruktose verhouding gevind vir beide kultivars. In terme van sure is Prime se wynsteensuur:appelsuur verhouding laer as in Crimson Seedless vir albei seisoene. Wynsteensuur is die hoof organiese suur in Prime terwyl appelsuur die hoof organiese suur in Crimson Seedless is. Geen betekenisvolle verskille vir na-oes houvermoë tussen korrelgroottes is waargeneem vir beide kultivars nie. Daar was egter tendense wat aanleiding gegee het in die aanname dat medium grootte korrels geneig is tot loskorrels in albei kultivars. Groot korrels het ‘n hoër korrelbars persentasie getoon vir beide kultivars. Crimson Seedless se tweede oes het plaasgevind 24 uur na reënval, wat aanleiding gegee het tot hoër persentasies korrelbederf. Hoër persentasie korrelbederf was ook gevind met later oesdatums. Geen beduidende verskille is gevind vir suiker:suur verhouding tussen die drie korrelgroottes vir beide kultivars nie. Dus word na-oes houvermoë nie net deur suiker:suur verhouding beïnvloed nie, maar ook deur oestyd en verpakkingsprodsedures. Omgewingsomstandighede voor oes kan ook na-oes houvermoë beïnvloed.

Spintronics is the study of mutual dependence of magnetization and electron transport, which forms a complementary picture in ferromagnetic (FM) materials. Recently, spintronics based on antiferromagnetic (AF) materials has been suggested. However, a systematic study is not yet available, and a complementary picture of the AF dynamics with electron transport is highly desired. By developing a microscopic theory, we predict the occurrence of spintronic phenomena both in bulk AF texture and on the interface of AF with normal metals. For the bulk, we find that the electron dynamics becomes adiabatic when the local staggered field is varying slowly over space and time, by which the spin-motive force and the reactive spin-transfer torque (STT) are derived as reciprocal effects. While the former generates a pure spin voltage across the texture, the latter can be used to drive AF domain wall and trigger spin wave excitation with lower current densities compared to FM materials. For the interface, by calculating how electrons scatter off a normal metal -antiferromagnet heterostructure, we derive the pumped spin and staggered spin currents in terms of the staggered order parameter, the magnetization, and their rates of change; the reactions of an incident spin current on the antiferromagnet is derived as STTs. These effects are applicable to both compensated and uncompensated interfaces with a similar order of magnitude. In contrast to FM materials, the direction of spin pumping is controlled by the circular polarization of driving microwave; and conversely, the chirality of AF spin wave is tunable by the direction of spin accumulation. / text

La taille du fruit est un caractère agronomique important pour le rendement des espèces cultivées.Or, excepté chez la tomate, les mécanismes impliqués dans la variation de la taille des fruits charnus sont encore mal connus. L'objectif de ma thèse était d'identifier les principaux facteurs anatomiques impliqués dans la variation de la taille des baies, de réaliser des tests d'association génétique sur des gènes candidats et de rechercher des possibles traces de domestication liées à la variation de la taille des baies. Le nombre de cellules déjà déterminé dans l’ovaire avant l’anthèse et la capacité des cellules du mésocarpe à grossir après l’anthèse se sont révélés les principaux déterminants de la variation de la baie entre les variétés. Trois gènes potentiellement impliqués dans ce caractère ont été identifiés par des approches de génétique d'association. La MADS boxVvAGL11 est associée au nombre de pépins de la baie. VvHMGR1, une HMGR impliquée dans la synthèse des isoprénoïdes précurseurs de régulateurs de croissance, est associée à la longueur des baies. Enfin, VvJMJ un facteur de transcription de type jumonji est à la fois associé à la variation du poids et à la longueur des baies. La caractérisation du locus Fleshless berry (Flb) a également été poursuivie avec (i) l’analyse du polymorphisme de séquence de 69 fragments de gènes entre les vignes sauvages et cultivées, ce qui a permis l’identification d’un gène présentant une trace de sélection et une diversité nucléotidique plus élevée dans le compartiment sauvage que dans lecultivé. (ii) La mise en évidence d’une homozygotie complète d’une région de 1 Mb contenant le locus Flb chez certains cultivars comme l’Ugni Blanc, rendant impossible le clonage positionnel du gène dans la population F1. L’ensemble de ce travail a permis de mettre en évidence la complexité des mécanismes à l’origine de la variation de la taille de la baie chez la vigne. Nous avons montré la faisabilité des études de génétique d’association chez la vigne en utilisant des gènes candidats pour le poids de baies, et identifié les candidats les plus intéressants pour la sélection assistée par marqueurs et les études fonctionnelles ultérieures. / Fruit size is an important trait in fruit crops. However, excepted in tomato, little is known about the genetic and molecular control of fleshy fruit size variation. The aim of my thesis was to identify themain anatomical factors underlying berry size variation, to carry out an association genetics based approach with candidate genes and to search for possible signatures of domestication linked toberry size variation. Cell divisions before anthesis and cell expansion after anthesis were found tobe the major determinants of flesh weight variation between varieties in grapevine. Three geneswere identified by association genetics approaches. The VvAGL11 MADS box was found associated only with the seed number per berry. VvHMGR1, a putative HMGR involved in the synthesis of isoprenoid, a precursor of plant growth regulators, was found associated with berry length. Finally,VvJMJ encoding a putative transcription factor jumonji was associated both with berry weight andberry length variation. The characterization of the Fleshless berry locus (Flb) was also pursued with(i) the analysis of the sequence polymorphism of 69 regions between wild and cultivated grapevines,that leaded to the identification of one gene showing a trace of selection and a higher nucleotide diversity in the wild compartment than in the cultivated compartment. (ii) The discovery of acomplete homozygosity of a 1 Mb region containing the Flb locus in some cultivars such as theUgni Blanc, making impossible the fine mapping of the Flb locus in a F1 population. This study has highlighted the complexity of the mechanisms underlying the berry size variation in grapevines. We demonstrated the feasibility to screen in grapevine by association genetics candidate genes for berryweight and to select the most interesting ones for marker-assisted selection and for furtherfunctional studies.

This study examines Wendell Berry’s cultural critique to identify implications for American education. It explores three themes in Berry’s fiction: land and place, community, and character, and considers Berry’s observations about education in his non-fiction and interviews. The health of natural resources is a fundamental value for Berry who believes that human beings have a moral obligation to be stewards of the Earth. Practicing stewardship enables the creation of valuable places. A vital connection links the health of the natural world and human community. Healthy communities are radically inclusive, work for a sustainable future, and care for those with special needs. Community “members” exemplify qualities of character, knowledge of the community, good work, and neighborliness, all essential for responsible stewardship. The study assesses Berry’s claims that: (1) formal schooling often lacks vibrant association with the local community; (2) our reliance on discrete academic disciplines fosters over-specialization and academic isolation; and (3) the standard for education should be revamped to focus on the health of the community rather than job preparation. American education often serves economic and political agendas that ignore the well-being of natural resources and human communities. In spite of our daunting challenges, Berry maintains hope and charts constructive steps forward. Students learn best, he believes, through apprenticeship and mentoring. The study concludes that with substantive changes education can play a major role in enabling students to grasp the needs of a healthy, life-supporting planet and to develop the skills, values, and disciplines of responsible community members. Replacing corporate-dominated, technology-driven, and shortsighted attitudes and behaviors with restorative practices and values requires commitment from all of society’s sectors, and perhaps especially from our schools, colleges, and universities.

La vigne est une plante cultivée dans le monde entier dont l’importance économique est principalement liée à la production de vin. La baie de raisin est également l’un des principaux modèles d’étude pour les fruits non-climatériques notamment pour l’étude des mécanismes contrôlant le mûrissement des baies. Le développement de la baie de raisin est caractérisé par deux phases de croissance séparées par une phase de latence se produisant au moment de la véraison. La baie de raisin est composée de trois tissus principaux: la peau, la pulpe et les graines. La peau et la pulpe présentent une structure et une composition en métabolites distinctes et contribuent de manière différente à la qualité du vin, la pulpe fournissant essentiellement le sucre, les acides aminés et organiques alors que la peau est riche en anthocyanes. A l'heure actuelle, les mécanismes moléculaires impliqués dans le contrôle de la maturation des baies de raisin sont encore mal compris. Si l'ABA, le sucre et différents facteurs de transcription jouent un rôle important dans le contrôle de cette phase de développement, les mécanismes épigénétiques, en particulier la méthylation de l’ADN, apparaissent aussi comme des régulateurs importants du développement et du mûrissement des fruits charnus. Dans ce contexte, Le projet de thèse présenté vise à analyser le rôle de la méthylation de l’ADN (1) dans la maturation des baies de raisin et (2) dans la synthèse des anthocyanes en utilisant comme système modèle des cellules de baie de raisin cultivées in vitro.La culture in vitro de baies de raisin en présence d’inhibiteurs de la méthylation de l'ADN, aboutit à une inhibition de la maturation, suggérant que la méthylation de l’ADN joue un rôle crucial pour cette étape du développement chez la vigne. La pellicule et la chair de baies de raisin récoltées à divers stades de développement ont ensuite été analysées séparément pour déterminer les variations des transcriptomes, de l’abondance de différents métabolites, et de la méthylation de l'ADN. Les principaux résultats indiquent des variations des métabolites et du transcriptome, avec des spécificités liés au tissu analysé. En outre, l'analyse des variations de méthylation de l'ADN à deux stades de développement dans chacun de ces deux tissus révèle l’existence de variations de méthylation spécifiques à chaque tissu, tandis que les variations communes aux deux tissus restent limitées. Ces résultats suggèrent un contrôle de la méthylation de l’ADN spécifique à chaque tissu lors de la maturation de la baie. Cependant les régions différentiellement méthylées identifiées dans chaque tissu, ne sont pas associées à des gènes exprimés différentiellement au cours de la maturation des baies, ce qui pose la question du rôle de la méthylation de l’ADN dans le contrôle de l’expression génique dans les baies.Pour analyser le rôle de la méthylation de l’ADN dans le contrôle de la synthèse des anthocyanes, nous avons utilisé des suspensions de cellules de raisin du génotype Gamay Teinturier (GT), connues pour accumuler des anthocyanes lorsqu’elles sont cultivées à la lumière. L’utilisation de la zébularine, un inhibiteur de la méthylation d’ADN, permet de stimuler l’accumulation d'anthocyanes dans les cellules GT en présence de lumière, et de l’induire à l’obscurité. Les traitements à la zébularine provoquent en outre une limitation de la croissance cellulaire, une modification de l’accumulation des sucres solubles et acides organiques ainsi qu’une reprogrammation importante du transcriptome. Ces résultats suggèrent un effet général de la zébularine sur les cellules GT plutôt qu’un effet spécifique sur l’accumulation d’anthocyanes.Dans l'ensemble, les résultats indiquent que la méthylation de l'ADN est importante pour le contrôle de la maturation des fruits de la vigne, bien que les mécanismes qui sous-tendent les variations de la méthylation et leurs rôles dans les différents tissus de la baie de raisin restent à préciser. / Grapevine is a worldwide cultivated fruit crop with high economic importance mainly because of its usage for vine production. Grape berry is also one of the main models for non-climacteric fruits to study the mechanisms controlling the ripening process. Grape berry development is characterized by two phases of rapid size increase separated by a lag phase at the time of ripening induction. Grape berries are composed of three main tissues, the peel, the pulp and the seeds. Peel and pulp present distinct structure and metabolite composition and contribute in a different way to wine quality, the pulp providing sugar, amino and organic acids whereas the peel is important for anthocyanins and other phenolic compound abundance. At the present time, the molecular mechanisms involved in the control of grape berry ripening are still poorly understood. Recent results indicate that both ABA and sugar may be important signals together with various transcription factors. In addition, epigenetic mechanisms are now emerging as important regulators of fleshy fruit development, DNA methylation being critically important for tomato, sweet range and strawberry ripening.The present project aims at analyzing the potential role of DNA methylation in the control grape berry ripening. It also investigates the potential role of DNA methylation in the synthesis of anthocyanins, a compound of primary importance in peel of red grape berries, using in vitro grown fruit cells. To address these questions, grape berries cultivated in vitro were treated with DNA methylation inhibitors. Treatments resulted in delayed and reduced grape berry ripening, therefore sustaining the idea that DNA methylation plays critical roles at this developmental step. Grape berries harvested at various developmental stages were then dissected and each tissue was separately analyzed for transcriptomic, metabolic and DNA methylation variations. Main results indicate significant and distinct metabolic and transcriptomic variations consistent with each tissue following specific modifications during ripening. In addition, analysis of DNA methylation variations at two developmental stages in each tissue indicates both common and tissue specific changes in DNA methylation patterns during fruit ripening. A very small proportion of DMRs is found similarly in the pup and the peel, but most are tissue specific, also consistent with tissue specific control at this developmental phase. Of note, among the different DMRs identified in each tissue, only a few were associated with differentially expressed genes (DEG) during ripening, whereas most were not, questioning the general role of DNA methylation in the control of gene expression at this developmental transition in grape.As Anthocyanins are the most abundant polyphenolic compounds in the skin of red grape berries, we used grape cell suspensions of the Gamay Teinturier genotype, that are known to accumulate anthocyanins when grown in light conditions, to analyze the potential role of DNA methylation in their synthesis. GT cells cultivated in light conditions were treated with the DNA methyltransferase inhibitor zebularine, they accumulate higher quantities of anthocyanins. Of note, GT cells grown in the absence of light do not accumulate anthocyanins. However, zebularine was sufficient to induce anthocyanin accumulation in the absence of light. Zebularine treatments had significant additional effects on grape cells including, cell growth limitation, and modification of soluble sugar, organic acid or stilbene accumulation, together with important transcriptomic reprogramming, consistent with a general effect on cells rather than a specific effect on anthocyanin accumulation.Taken together, results are consistent with DNA methylation being important in the control of grape fruit ripening, although the precise mechanisms underlying methylation variations and roles in grape berries remain to be deciphered.

No description available.