Master of Science / Food Science Program / Thomas J. Herald / For the last decade in the U.S., consumers have demanded fresh, healthier convenience-type foods namely, fresh-cut vegetables. Globalization has played a major role in rapid growth of the fresh-cut industry sector. Thus, consumers may purchase their favorite seasonal vegetables in local grocery stores year-round. However, the convenience of year-round produce availability brings the potential of foodborne outbreaks. Thirty-two states reported 190 produce-associated outbreaks, 16,058 reported illnesses, 598 hospitalizations, and eight deaths from 1973 to 1997. Pathogenic bacteria contaminate raw agricultural commodities through various pathways such as irrigation with untreated water, use of noncomposted animal manure as fertilizer, and wash water systems. The increasing number of produce-related outbreaks has raised awareness to interventions that remove human pathogens on fresh produce. Washing solely with tap water cannot be relied upon to completely remove pathogens. Chlorinated water is the most frequently used sanitizer, however, reductions are less than 2.63-log CFU/g on leafy and salad vegetables. Such reductions, although significant, are not sufficient to assure the microbial safety of minimally processed vegetables. The efficacy of several other chemical agents such as chlorine dioxide, ozone, electrolyzed water, hydrogen peroxide, organic acids, and other commercial products have been evaluated as potential alternatives to chlorine.

Escherichia coli produtora de toxina Shiga (STEC) está entre os patógenos envolvidos em surtos de doenças transmitidas por alimentos devido ao consumo de vegetais. No entanto, até agora, os relatos sobre a presença de STEC em vegetais no Brasil são escassos. Esse microrganismo é veiculado por alimentos, contaminados direta ou indiretamente por fezes animais, sendo responsável por um amplo espectro de doenças que compreende desde diarréia leve que pode evoluir para colite hemorrágica (CH), até síndrome hemolítico-urêmica (SHU) e púrpura trombocitopênica trombótica (PTT). O presente estudo teve como objetivo investigar a presença de STEC em vegetais orgânicos cultivados na região metropolitana da cidade de São Paulo, Brasil, caracterizando os fatores de virulência stx1, stx2, eae e ehx, bem como o sorotipo. Um total de 200 amostras de vegetais orgânicos (folhas verdes), obtido a partir de três produtores foi analisado quanto à presença de cepas de STEC. Caldo triptona de soja (TSB) suplementado com vancomicina (8 mg / L), cefixima (50 µg / L) e telurito de potássio (2,5 mg / L) foi utilizado na etapa de pré-enriquecimento, com incubação a 37ºC / 24 h, seguido por semeadura em MacConkey Sorbitol (SMAC) e CHROMagar STEC (CHROM). Após incubação a 37ºC / 24 h, as colônias suspeitas foram confirmadas por testes bioquímicos e submetidas a PCR objetivando a detecção dos genes de virulência stx1, stx2, eae, ehx, e os genes fliCH7 e rfbO157. Entre as 200 amostras de vegetais orgânicos analisadas, 30 (15%) foram positivas para E. coli, mas nenhum isolado apresentou os genes de virulência pesquisados. Nossos resultados indicam baixo risco de infecção devido ao consumo destes produtos frescos em São Paulo, Brasil. No entanto, são necessárias mais pesquisas, abrangendo um maior número de amostras e área pesquisada, uma vez que este patógeno já foi encontrado no meio ambiente em estudos anteriores e poucas pesquisas investigaram a presença de STEC em vegetais no Brasil. / Shiga toxin producing Escherichia coli (STEC) strains are among the pathogens involved in foodborne disease outbreaks due to consumption of vegetables. However, reports on the presence of STEC in vegetables in Brazil are lacking. STEC is an important pathogen transmitted by food, directly or indirectly contaminated with animal feces, responsible for a broad spectrum of diseases varying from mild diarrhea to hemorrhagic colitis (HC), syndrome hemolytic uremic (HUS) and thrombotic thrombocytopenic purpura (TTP). This study aimed at investigating the presence of STEC in organic vegetables in the metropolitan region of São Paulo city, Brazil, characterizing the virulence factors stx1, stx2, eae and ehx as well as identifying the serotype. A total of 200 samples of organic vegetables (green leafy), obtained from three organic producers was analyzed for the presence of STEC strains. Tryptic Soy Broth (TSB) supplemented with vancomycin (8mg/L), cefixim (50µg/L) and potassium telurite (2.5mg/L) was used in the pre enrichment step with incubation at 37°C/24 h, followed by plating onto Sorbitol-MacConkey (SMAC) agar and CHROMagar STEC (CHROM). After incubation at 37°C/24 h, presumptive colonies were confirmed by biochemical tests and submitted to PCR targeting the detection of stx1, stx2, eae and ehx virulence genes, as well as fliCH7 and rfbO157. Among the 200 organic vegetable samples analyzed for STEC strains, 30 (15%) were positive for E. coli, but none of them showed the virulence genes studied. These findings indicate low risk of infection due to the consumption of these fresh produce in Sao Paulo, Brazil. However, more research is required, covering a larger number of samples and area, since this pathogen has already been found in the environment in previous studies, and few research investigating the presence of STEC in vegetables has been reported in Brazil.

Estudos sobre a vitamina K têm evidenciado seu papel na manutenção da saúde óssea e vascular. A atuação desta vitamina em tecidos extra-hepáticos não é considerada na recomendação dietética da DRI de 2001, sendo reconhecidas necessidades maiores para função óssea em pessoas acima dos 60 anos e em indivíduos que fazem uso de medicamentos antivitamina K. Visando colaborar com pesquisas futuras, onde o conhecimento do teor de vitamina K1 é relevante, além de contribuir com dados para Tabela Brasileira de Composição de Alimentos - TBCA-USP, o presente trabalho foi conduzido para determinação do teor de filoquinona (vitamina K1) de hortaliças consumidas na cidade de São Paulo. As hortaliças analisadas foram escolhidas após a conclusão de um inquérito alimentar realizado, com adultos e idosos, num projeto de pesquisa desenvolvido junto ao Departamento de Alimentos e Nutrição Experimental da FCF/USP visando a análise da ingestão diária de vitamina K. Desta forma, foram analisadas as hortaliças mais consumidas por esses grupos, submetidas ou não ao processo de cocção. Estas amostras foram adquiridas diretamente na CEAGESP - Companhia de Entrepostos e Armazéns Gerais de São Paulo. As metodologias empregadas na determinação da filoquinona (vitamina K1) foram extração e purificação pelo método líquido-líquido utilizando solventes orgânicos e quantificação através da Cromatografia Líquida de Alta Eficiência (CLAE). Os resultados mostraram que as amostras de hortaliças de colorações verdes mais escuras apresentaram os maiores teores da vitamina como: salsa 491,05 µg/100g; espinafre 375,01 µg/100g, quando comparados com as amostras de colorações verdes mais claras as quais como é o caso da alface americana 113,42 µg/100g e a couve-flor 32,55 µg/100g. A maioria das hortaliças analisadas apresentaram variações entre as diferentes épocas do ano e quando comparadas com dados da literatura. / Studies on vitamin K have shown its role in maintaining bone and vascular health. The role of this vitamin in extrahepatic tissues is not considered in the dietary recommendation of DRI 2001. Increased need for vitamin K intake is recognized for the bone function in people over age 60 and individuals who use anti-vitamin K drugs. Aiming at supporting future research, where knowledge of vitamin K1 is relevant, and contribute data to the Brazilian Table of Food Composition - TBCA-USP, this study was conducted to determine the level of phylloquinone (vitamin K1) of vegetables consumed in the city of São Paulo. The vegetables studied were chosen after completion of a nutrition survey carried out with adults and elderly people, a research project developed by the Department of Food and Experimental Nutrition FCF / USP aimed at analyzing the daily intake of vitamin K. Therefore, we analyzed the most consumed vegetables by these groups submitted or not to the cooking process. These samples were acquired directly at CEAGESP - General Warehouses Company of São Paulo. The methodologies employed in the determination of phylloquinone (vitamin K1) were extraction and purification method using liquid-liquid organic solvents followed by High Performance Liquid Chromatography (HPLC). The results showed that the samples of darker green vegetables showed the highest levels of vitamin such as parsley (491.05 µg/100g) and spinach (375.01 µg/100g), when compared with samples of lighter coloration (e.g. 113.42 µg/100g lettuce, and 32.55 µg/100g cauliflower). Most vegetables analyzed showed variation in results when compared to the different seasons and the literature data.

An effective and rapid method for the separation of bacteria from food matrix remains a bottleneck for rapid bacteria detection for food safety. Bacteria can strongly attach to the food surface or internalize within the matrix which makes their isolation extremely difficult. Traditional methods of separating bacteria from foods routinely involve stomaching, blending and shaking, however these methods may not be efficient at removing all the bacteria from complex matrices. Here, we investigate the benefits of using enzyme digestion followed by immunomagnetic separation to isolate Salmonella from spinach and lettuce. Enzymatic digestion using pectinase and cellulase was able to break down the structure of the leafy green vegetables resulting in the detachment and release of Salmonella from the leaves. Immunomagnetic separation of Salmonella from the liquefied sample allowed an additional separation step to achieve a more pure sample without leaves debris that may benefit additional downstream applications. We have investigated the optimal combination of pectinase and cellulase for the digestion of spinach and lettuce to improve sample detection yields. The concentrations of enzymes used to digest the leaves were confirmed to have no significant effect on the viability of the inoculated Salmonella. Results reported that the recovery of the Salmonella from the produce after enzyme digestion of the leaves was significantly higher (P

Lettuce is becoming an increasingly important vegetable, both as a fresh market product and a ready-to use vegetable, especially in urban areas of South Africa. Nutrient solution concentration is one of the most practical and effective ways of controlling and improving the yield and nutritional quality of crops for human consumption. However, optimal fertilizer concentration for leafy vegetables also depends on the prevailing environmental conditions. This study was carried out to determine the effects of different nutrient solution concentrations and growing seasons on growth, yield and quality of leafy lettuce. The trial was conducted in a black and white shade net structure and the nutrient concentration treatments were 1.0, 2.0, 3.0, and 4.0 mS.cm-1. Measurements taken included: leaf number, leaf area, fresh leaf mass, dry leaf mass, dry root mass, as well as chlorophyll content. The sensory evaluation procedure was only done on plant samples grown during summer and winter seasons. The results showed that growth was less affected by nutrient concentration than by growing season. Regardless of the nutrient concentration, plants grown in summer reached maturity quicker as compared to plants grown in winter. Generally, leaf number, leaf area, leaf area index, fresh leaf mass, dry leaf mass and dry root mass did not significantly increase with increasing nutrient concentrations and therefore, yield was not influenced by nutrient concentrations. Quality was influenced by nutrient concentrations during the summer-autumn seasons where increasing nutrient concentration induced increased chlorophyll content of the leaves. During the winter-spring seasons this phenomenon was not significant. The study demonstrated that growth, yield and quality of lettuce were not significantly influenced by nutrient solution concentrations of 1.0, 2.0, 3.0 and 4.0 mS.cm-1. The sensory evaluation also showed no significant differences on the colour (quality) and flavor of the lettuce samples grown during summer and winter seasons and unfortunately it was not done during autumn and spring seasons. Irrespective of the nutrient solution concentration, growth was influenced by growing season because plants grown during summer reached maturity quicker as compared to plants grown during the other seasons. / Dissertation (MInstAgrar)--University of Pretoria, 2012. / Plant Production and Soil Science / unrestricted

Concern regarding the decline in the knowledge and use of indigenous green vegetables exists in many southern African regions including Swaziland. Reasons for this are, amongst others, attributed to a lack of inter-generational knowledge transfer, the influence of westernisation and changing food values and attitudes, as people nowadays regard indigenous green leafy vegetables as a low status food. It is imperative that knowledge of these foods be documented before it is lost to future generation. Indigenous green leafy vegetables have long been considered healthier options than the many recently introduced western-orientated foods, which are closely linked to chronic lifestyle diseases. The aim of this study was to determine, describe and compare the knowledge of indigenous green leafy vegetables among two generations of rural Swazi women from the Eluyengweni community, and how it manifests in their food practices. Studies on indigenous green leafy vegetables in Swaziland are limited. This study will fill the knowledge gap in this field. The human ecological perspective was adopted as theoretical perspective and an explorative mixed method approach was followed. Qualitative data was collected through focus group discussions with younger (25-45 years) and older (over 45 years) women. Face-to-face structured interviews provided quantitative data on the knowledge the women had of indigenous green leafy vegetables, including their procurement, preparation, preservation and consumption patterns. The convenience sample comprised 102 respondents. Observation was done concurrently during both phases of data collection and photographs accompanied comprehensive field notes. It transpired that the availability of indigenous green leafy vegetables had declined in the community and those that were available were not easily accessible as they were located on the outskirts of the community. In spite of changes in the physical and natural environment, some indigenous green leafy vegetable species are still available in summer. It is clear that the older women, in comparison to their younger counterparts, had more knowledge of indigenous green leafy vegetables in terms of identifying them, where they are found and how they are used. Familiar and available indigenous green leafy vegetables such as imbuya (Amaranthus), chuchuza (Bidens pilosa) were preferred, and consumed fairly regularly. Although indigenous green leafy vegetables were still part of the food practices in this community, their consumption among the younger generation had declined. However, due to factors related to modernisation, economic influences and technological advancement the majority of both the younger and older participants seem to have become dependent on, and often include, western-orientated food in their food consumption patterns. Based on the results, recommendations are made to capture and preserve the knowledge of indigenous green leafy vegetables in this community and to revive interest in these vegetables and promote their consumption. / Daar is 'n besorgdheid oor die afname in kennis in die gebruik van inheemse groen blaargroentes in baie streke in Suider Afrika, insluitend Swaziland. Redes wat hiervoor aangevoer word, is onder andere, die gebrekkige oordrag van kennis van een geslag na die volgende, die invloed van verwestering asook 'n verandering in waardes en houdings aangesien mense inheemse groen blaargroentes deesdae as 'n lae status voedsel beskou. Daarom is dit noodsaaklik dat kennis oor hierdie voedsel gedokumenteer word voordat dit verlore gaan vir die nageslag. Inheemse groen blaargroentes word gesonder geag in vergelyking met Westers-georienteerde voedsel, wat op hul beurt nou geassosieer word met kroniese lewenstyl siektes. Die doel van hierdie studie was om die kennis van inheemse groen blaargroentes van twee geslagte landelike Swazi vroue van die Eluyengweni gemeenskap te bepaal, beskryf en te vergelyk asook hoe dit manifesteer in hul voedselpraktyke. Studies oor inheemse groen blaargroentes in Swaziland is beperk en hierdie studie dra by om die leemte in kennis in hierdie studieveld te vul. Die menslike ekologiese perspektief is a teoretiese perspektief gebruik en 'n verkennende gemengde metodologie is as navorsingsbenadering gevolg. Kwalitatiewe data is deur middle van fokusgroep gesprekke met beide die jonger (25-45 jaar) en ouer (ouer as 45 jaar) vroue ingesamel. Met behulp van gestruktureerde individuele onderhoude is kwantitatiewe data oor die kennis van inheemse groen blaargroentes ingesamel wat die verkryging, voorbereiding, preservering en verbruikspatrone van hierdie groentes ingesluit het. 'n Geriefssteekproef van 102 respondente het aan die studie deelgeneem. Waarnemings is gedurende beide fases van die data insameling uitgevoer en fotos en volledige veldnotas is ingesluit. Dit is duidelik dat die beskikbaarheid van inheemse groen blaargroentes in hierdie gemeenskap afgeneem het, en dit wat beskikbaar was, was nie maklik toeganklik nie, omdat dit aan die buitewyke van die gemeenskap gelëe was. Ten spyte van die verandering in die fisiese en natuurlike omgewing is sommige inheemse groen blaargroentes steeds beskikbaar gedurende die somer. Dit is duidelik dat die ouer vroue, in vergelyking met die die jonger vroue oor meer kennis van inheemse groen blaargroentes beskik het met betrekking tot die identifisering, waar hulle groei en hoe om hulle te gebruik. Bekende en beskikbare inheemse groen blaargroentes soos gewone misbredie (Amaranthus) en knapsakkerwel (Bidens pilosa) was voorkeur groente en is redelik gereeld gebruik. Alhoewel inheemse groen blaargroentes steeds deel vorm van die voedselpraktyke in hierdie gemeenskap, het die gebruik daarvan deur die jonger geslag afgeneem. As gevolg van faktore soos modernisering, die ekonomie en tegnologiese vooruitgang het die meerderheid van beide die jonger en ouer geslag afhanklik geword van westers-georienteerde voedsel en dit dikwels in hulle eetpatrone ingesluit. Die resultate van hierdie studie het bygedra dat aanbevelings oor die vaslegging en bewaring van die kennis oor inheemse groen blaargroentes in hierdie gemeenskap gemaak kon word, asook om 'n oplewing in die belangstelling in die gebruik daarvan te bevorder. / Dissertation (MConsumer Science)--University of Pretoria, 2017. / Consumer Science / MConsumer Science / Unrestricted

No description available.

Le grain de maïs est composé de 3 compartiments : l’embryon et l’albumen issus de la double fécondation et l’enveloppe d’origine maternelle. Le développement du grain et l’accumulation de réserves demande l’établissement d’une communication étroite entre l’embryon et l’albumen pour coordonner leur développement respectif. Si, des régulateurs majeurs impliqués dans le développement de la graine d’Arabidopsis ont été décrits, ces connaissances restent parcellaires chez les céréales. Les objectifs de ma thèse consistaient d’une part à étudier le contrôle de la communication entre l’embryon et l’albumen et d’autre part la régulation du remplissage du grain de maïs. Par l’analyse de lignées transgéniques sous exprimant ZmZHOUPI (ZmZOU-RNAi), nous avons établi que ce facteur de transcription à domaine bHLH, bien que s’exprimant exclusivement dans l’albumen, affecte significativement le développement de l’embryon (taille de l’embryon, persistance du suspenseur). L’analyse de données RNAseq (grains sauvages versus grains ZmZOU-RNAi) a permis d’identifier des gènes cibles potentiels de ZmZOU. De plus, nous avons montré que 3 facteurs de transcription de type bHLH homologues d’INDUCER OF CBP EXPRESSION (ICE) forment un partenariat avec ZmZOU.D’autre part, nous avons étudié les homologues d'ABA INSENSITIVE3, FUSCA3 et LEAFY COTYLEDON2 (AFL) qui forment un réseau de facteurs de transcription, à domaine B3, régulant l’accumulation d’huile et de protéines de réserves dans l’embryon d’Arabidopsis. Grâce à des analyses phylogénétiques et d’expression, nous avons établi que chez le maïs le réseau AFL, constitué de 5 membres (ZmAFLs), est partiellement conservé. Par dosages et analyse d’expression, nous avons montré que ZmAFL4, en particulier, est impliqué dans le contrôle de la biosynthèse de l’amidon dans l’albumen. / Maize kernel is composed of three major compartments: an embryo and an endosperm both produced by double fertilization and the maternally derived seed coat. Seed development and reserves accumulation demands coordination and thus communication between embryo and endosperm allowing specific growth of each compartment. While major regulators involved in seed development have been already described in Arabidopsis, knowledge in cereals remains limited. My thesis purposes were to study on one hand the control of communication between embryo and endosperm and on the other hand regulation of maize kernel filling.By analysis of transgenic lines knock down ZmZHOUPI (ZmZou-RNAi), we showed that this bHLH domain transcription factor, exclusively expressed in endosperm, affect significantly embryo development, size of embryo proper and suspensor persistence. RNAseq data analyses let find putative direct targets of ZmZOU. Additionally, we identified ZmZOU partners, 3 bHLH domain transcription factor homologs of INDUCER OF CBP EXPRESSION (ICE).Furthermore, we studied homologs of three B3 domain transcription factors named ABA INSENSITIVE3, FUSCA3 et LEAFY COTYLEDON2 (AFL) which form a regulatory network governing oil and seed storage proteins accumulation in Arabidopsis embryo. By phylogenetic and expression analysis, we established that 5 genes (ZmAFLs) constitute in maize a partially conserved AFL network. Through dosage and expression analysis, we established that particularly ZmAFL4 is involved in starch biosynthesis regulation.

Bauhinia s.l. est le plus vaste genre de la tribu des Cercideae (Ceasalpinioideae, Leguminoseae), avec plus de 300 espèces. Il présente une distribution pantropicale et une grande variabilité morphologique. Ces deux caractéristiques ont limité les études taxonomiques sur le genre complet, résultant en plusieurs études taxonomiques de certains groupes seulement. En 1987, Wunderlin et al. proposent une vaste révision taxonomique de la tribu des Cercideae, basée sur des données morphologiques, et divisent le genre Bauhinia en quatre sous-genres. En 2005, Lewis et Forest publient une nouvelle classification préliminaire basée sur des données moléculaires, mais sur un échantillonnage taxonomique restreint. Leurs conclusions remettent en question le monophylétisme du genre Bauhinia et suggèrent plutôt la reconnaissance de huit genres au sein du grade Bauhinia s.l. Afin de vérifier les hypothèses de Lewis et Forest, et obtenir une vision plus claire de l’histroire de Bauhinia s.l., nous avons séquencé deux régions chloroplastiques (trnL-trnF et matK-trnK) et deux régions nucléaires (Leafy et Legcyc) pour un vaste échantillonnage représentatif des Cercideae. Une première phylogénie de la tribu a tout d’abord été réalisée à partir des séquences de trnL-trnF seulement et a confirmé le non-monoplylétisme de Bauhinia s.l., avec l’inclusion du genre Brenierea, traditionnellement reconnu comme genre frère de Bauhinia s.l. Afin de ne pas limiter notre vision de l’histoire évolutive des Cercideae à un seul type de données moléculaires et à une seule région, une nouvelle série d’analyse a été effectuée, incluant toutes les séquences chloroplastiques et nucléaires. Une phylogénie individuelle a été reconstruite pour chacune des régions du génome, et un arbre d’espèce ainsi qu’un arbre de supermatrice ont été reconstruits. Bien que certaines contradictions apparaissent entre les phylogénies, les grandes lignes de l’histoire des Cercideae ont été résolues. Bauhinia s.l. est divisée en deux lignées : les groupes Phanera et Bauhinia. Le groupe Bauhinia est constitué des genres Bauhinia s.s., Piliostigma et Brenierea. Le groupe Phanera est constitué des genres Gigasiphon, Tylosema, Lysiphyllum, Barklya, Phanera et Schnella. Les genres Cercis, Adenolobus et Griffonia sont les groupes-frères du clade Bauhinia s.l. Au minimum un événement de duplication de Legcyc a été mis en évidence pour la totalité de la tribu des Cercideae, excepté Cercis, mais plusieurs évènements sont suggérés à la fois par Legcyc et Leafy. Finalement, la datation et la reconstruction des aires ancestrales de la tribu ont été effectuées. La tribu est datée de 49,7 Ma et est originaire des régions tempérées de l’hémisphère nord, probablement autour de la mer de Thétys. La tribu s’est ensuite dispersée vers les régions tropicales sèches de l’Afrique, où la séparation des groupes Bauhinia et Phanera a eu lieu. Ces deux groupes se sont ensuite dispersés en parallèle vers l’Asie du sud-est au début du Miocène. À la même période, une dispersion depuis l’Afrique de Bauhinia s.s. a permis la diversification des espèces américaines de ce genre, alors que le genre Schnella (seul genre américain du groupe Phanera) est passé par l’Australie afin de rejoindre le continent américain. Cette dispersion vers l’Australie sera également à l’origine des genres Lysiphyllum et Barklya / Bauhinia s.l. is the largest genus of the tribe Cercideae (Ceasalpinioideae, Leguminoseae), with over 300 species. It has a pantropical distribution and high morphological variability. These two features have resulted in few studies that focus on the entire genus, resulting in several regional studies or studies of certain subgroups only. In 1987, Wunderlin et al. presented a broad taxonomic revision of the tribe Cercideae, based on morphological data, and divided the genus Bauhinia into four subgenera. In 2005, Lewis and Forest published a new preliminary classification based on molecular data, but for a limited taxonomic sampling. Their findings question the monophyly of the genus Bauhinia and suggest instead the recognition of eight genera in the Bauhinia s.l. grade. To test the hypotheses of Lewis and Forest, and to obtain a clearer view of the history of Bauhinia s.l., we sequenced two chloroplast regions (trnL-trnF and matK-trnK) and two nuclear regions (Leafy and Legcyc) for a large representative sampling of the Cercideae. A primary phylogeny of the tribe was first generated based on trnL-trnF sequences only and confirmed the non-monophyly of Bauhinia s.l., with the inclusion of the genus Brenierea, traditionally recognized as sister group of Bauhinia s.l. In order to obtain a deaper view of the evolutionary history of the Cercideae, a new series of analysis was performed, including all nuclear and chloroplast sequences. Individual phylogenies were reconstructed for each region of the genome, and both a species and a supermatrix trees were reconstructed. Although certain conflicting relationships appear between phylogenies, the outline of the history of the Cercideae has been resolved. Bauhinia s.l. is divided into two lineages: Phanera and Bauhinia groups. The Bauhinia group includes Bauhinia s.s., Piliostigma and Brenierea. The Phanera group is composed of Gigasiphon, Tylosema, Lysiphyllum, Barklya, Phanera and Schnella. Cercis, Griffonia and Adenolobus are sister groups of Bauhinia s.l. At least one duplication event of Legcyc has been highlighted for the entire tribe Cercideae, excluding Cercis. Several other duplication events are also suggested by both Legcyc and Leafy . Finally, a divergence time analysis and a reconstruction of ancestral areas were conducted. The root of the tribe is evaluated to be 49.7 Mya old, and to originate from temperate regions in the northern hemisphere, mostly around the Tethys Sea. The tribe then dispersed into drier biomes in Africa, where the separation of the Bauhinia and the Phanera groups occurred. These two lineages then dispersed following parallel routes to Southeast Asia in the early Miocene. At the same time, a dispersal of the African Bauhinia s.s. to South America permitted the diversification of the American species of this genus, and Schnella (the only American genus within the Phanera group) dispersed to the American continent from Australia. This dispersal to Australia is also at the origin of Lysiphyllum and Barklya.

As folhas das angiospermas sofreram grandes modificações funcionais e estruturais ao longo do tempo, e atualmente apresentam uma ampla diversidade de formas, tamanhos e arranjos. Por exemplo, na tribo Bignonieae (Bignoniaceae), as folhas são geralmente 2-3-folíoladas, e o folíolo terminal é frequentemente modificado em gavinha. As gavinhas dos representantes de Bignonieae apresentam formas variadas (simples, bífidas, trífidas ou multífidas) e estão possivelmente envolvidas na diversificação da tribo. Apesar da importância das gavinhas para as plantas escandentes, pouco ainda é conhecido sobre esses órgãos nas angiospermas. Atualmente, existem dados disponíveis sobre genes que controlam o desenvolvimento de gavinhas foliares apenas para Pisum sativum (ervilha). Embora a maioria das angiospermas tenha o desenvolvimento de suas folhas controlado pelos genes KNOX1, em P. sativum, KNOX1 não é expresso nos primórdios foliares e seu desenvolvimento é regulado por LEAFY/FLORICAULA (LFY/FLO). Esses dados sugerem que folhas com gavinhas em outras espécies de planta também podem ser reguladas exclusivamente por LFY/FLO. O presente estudo investigou a evolução e o desenvolvimento dos diferentes tipos de gavinhas em Bignonieae e visou entender como mudanças na morfogênese foliar geraram os padrões atuais de variação morfológica das mesmas. Analisou-se o padrão de expressão dos genes SHOOTMERISTEMLESS (STM, gene KNOX1), PHANTASTICA (PHAN) e LFY/FLO durante o desenvolvimento foliar de três espécies de Bignonieae com diferentes tipos de gavinhas (simples, trífidas e multífidas), buscando um melhor entendimento da estrutura geral, origem e base genética do desenvolvimento das gavinhas foliares neste grupo. Nossos resultados demonstraram que as folhas se desenvolvem de maneira acrópeta em Bignonieae, bem como indicaram que gavinhas trífidas são ancestrais na tribo, com a evolução dos outros tipos de gavinhas tendo envolvido mudanças heterocrônicas no padrão de desenvolvimento básico das folhas. Além disso, transcritos do gene STM foram detectados em folhas em desenvolvimento, revelando que as folhas em Bignonieae se desenvolvem de maneira diferente das folhas de P. sativum, embora ambas apresentem gavinhas. Analises anatômicas revelaram que as gavinhas apresentam simetria bilateral e possuem algumas características similares aos folíolos, corroborando indicações previas de que as gavinhas de Bignonieae representariam folíolos modificados. Estas conclusões foram reforçadas pelo padrão de expressão encontrado para o gene PHAN (gene de identidade adaxial), cujos transcritos estavam confinados ao domínio adaxial do primórdio de gavinha em espécies que possuem gavinhas ramificadas, num padrão muito similar ao padrão observado nos primórdios dos folíolos. Em B. callistegioides, espécie que possui gavinhas simples, PHAN é expresso uniformemente por toda a gavinha, indicando que o domínio adaxial não foi corretamente estabelecido. Assim, as diferenças encontradas nos padrões de expressão do gene PHAN entre espécies com diferentes tipos de gavinhas em Bignonieae indica a existência de uma possível correlação entre a expressão do PHAN com a ramificação de gavinhas. Além disso, o padrão de expressão encontrado sugere que PHAN pode ter um papel importante no estabelecimento da polaridade em gavinhas e no surgimento dos vários tipos de gavinha encontrados na tribo. Além disso, o padrão de expressão do LFY/FLO em primórdios foliares nos levou a inferir que LFY/FLO pode ter um papel importante na separação de novos órgãos a partir de zonas meristemáticas. / Angiosperm leaves have undergone major functional and structural modifications over time, and currently exist in a wide diversity of forms, sizes, and arrangements. For example, in the tribe Bignonieae (Bignoniaceae), leaves are generally 2-3-foliolated, and the terminal leaflet is often modified into tendrils.These tendrils present varied morphologies (simple, bifid, trifid or multifid) and are thought to have been involved in the diversification of Bignonieae. Despite the importance of tendrils for climbing plants, little is still known about the biology of tendrils in the angiosperms. To date, no data is available on the genes that control tendrilled-leaf development in species other than pea (Pisum sativum). Even though KNOX1 genes control leaf development in the majority of compound-leaved angiosperms, in pea, KNOX1 is completely excluded from the leaf primordium and its development is regulated by LEAFY/FLORICAULA (LFY/FLO). This observation suggests that the development of other tendrilled-leaves might also be exclusively regulated by LFY/FLO as well. This study investigated the evolution and development of tendril types in Bignonieae in order to further understand how changes in leaf morphogenesis led to current patterns of variation in tendril morphology. We further analyzed the expression patterns of SHOOTMERISTEMLESS (STM, KNOX1 gene), PHANTASTICA (PHAN) and LFY/FLO during leaf development in three representatives of Bignonieae with different tendril types in order to better understand the structure, origin and genetic basis of leaf tendrils in this plant clade. Our results demonstrate that leaves in Bignonieae develop acropetally, as well as indicates that trifid tendrils are ancestral in the tribe, with the evolution of other tendril types involving heterochonic shifts in the leaf basic developmental pathway. Furthermore, transcripts of STM were detected in developing leaves, revealing that tendrilled leaves of Bignonieae develop differently from those of pea. The anatomical analysis revealed that tendrils are bilaterally symmetrical and present some characteristics that are similar to leaflets, further corroborating earlier suggestions that tendrils indeed represent modified leaflets. This observation was further reinforced by the expression pattern of PHAN (an adaxial identity gene), as PHAN transcripts were confined to the adaxial domain of the tendril primordia in branched-tendrilled species, in a pattern very similar to that observed in leaflet primordia. In B. callistegioides, a simple-tendrilled species, PHAN was expressed throughout the entire tendril, indicating a certain degree of disruption in the establishment of the adaxial domain. The differences encountered in the expression pattern of PHAN amongst species with different tendril types indicate a possible correlation of the expression of PHAN with tendril branching. Furthermore, it suggests an important role for PHAN in the establishment of tendril polarity and in the rise of the various tendril types encountered in Bignonieae. In addition, the pattern of expression of LFY/FLO in developing leaves has led us to infer that LFY/FLO may present an important role for the separation of new organs from meristematic zones.