Temperate maize is one of few model species that relies mainly on endogenous indicators of the plant’s developmental stage to cue the onset of reproductive development. The INDETERMINATE1 (ID1) transcription factor is a key regulator of the floral transition and id1 mutants are very late-flowering. ID1 is expressed and remains localized in developing leaves, while florigenic signals originate in mature, photosynthetically active leaves. Since very little is known about the molecular components of the floral transition in maize, and in autonomously flowering species at large, this work utilized id1 mutants to analyze the transcriptional and physiological alterations associated with the floral transition in maize. Analyses of functional categories of transcriptional change between developing leaves of id1 non-flowering mutants and normal flowering maize suggest a role for ID1 in energy metabolism and epigenetic regulation of leaf development. In addition, a novel family of -glucosidase genes were found to be expressed exclusively in immature leaves of normal flowering maize in a pattern similar to the ID1 gene suggesting that these genes may act in concert downstream of ID1. Further, profiling of transcript and metabolite alterations in mature leaves, which are likely the source of floral cues, suggest that coordination of resource storage in the form of transitory starch is an important signal for floral promotion in maize. Finally, analysis of the floral transition in Balsas teosinte, the progenitor of modern maize and an obligate short-day plant, suggests that ID1 may define a regulatory module unique to the autonomous floral regulation pathway in maize and related grass species.

Successful reproduction in plants is a highly-regulated process reliant on the integration of both endogenous and external cues. Different accessions of the model plant Arabidopsis thaliana have been collected, including those with a winter annual or rapid-cycling flowering habit. Natural variation and mutant screens have enabled many flowering time genes to be identified. A key regulator of flowering is FLOWERING LOCUS C (FLC). FLC is a repressor of flowering and is regulated by a number of genes, including those in the autonomous and FRIGIDA-mediated pathways. Of particular interest are FRIGIDA (FRI) and FRIGIDA-LIKE 1 (FRL1) and the autonomous pathway members, FCA and FY. FRI and FRL 1 promote FLC expression making them dominant repressors of flowering. FRI is proposed to initiate chromatin remodelling at the FLC locus leading to increased FLC expression. Once elevated, FLC levels are maintained until plants undergo an extended period of cold, therefore flowering occurs in spring. In contrast, FCA and FY promote flowering by repressing FLC expression. FCA has also been identified as a receptor of the plant hormone abscisic acid (ABA). Upon binding to FCA, ABA is proposed to disrupt/inhibit the FCA:FY interaction which results in delayed flowering. To characterise the FCA:ABA interaction and identify the ABA binding site, a number of truncated FCA proteins were utilised. Initially a FCA:FY GST-pulldown was used to identify the ABA binding site. However, when ABA failed to inhibit the FCA:FY interaction a direct binding assay using [�H]-ABA was employed. Another Arabidopsis ABA receptor, G-protein coupled receptor 2 (GCR2), was used as a positive control in these binding assays. Both FCA and GCR2 failed to bind [�H]-ABA suggesting a broader issue with the binding assay. The identification of FCA and GCR2 as ABA receptors can be attributed to the quality of the protein assayed, the sensitivity of the binding assay and the subsequent data analysis. This study resulted in the retraction of the original paper (Razem et at, 2006) reporting FCA as an ABA receptor. To investigate the molecular mechanism by which FRI and FRL1 act as positive regulators of FLC expresion, a biochemical approach was taken. FRI and FRL1 have no known homology to any other protein or domain and the only method for assessing protein function is through plant complementation experiments. In the absence of sequence homology, or a timely functional assay, a classical approach was taken to produce soluble protein for analysis. Truncation of predicted regions of disorder and expression, solubility and stability screens produced soluble protein of reasonable purity. This allowed characterisation of the biochemical properties of FRI and FRL1. Interaction studies between FRI and FRL1, and the zinc finger protein SUPRESSOR OF FRIGIDA 4 (SUF4), were also carried out. Polyclonal antibodies against FRI and FRL1, made during this study, were useful for protein detection in these experiments. The interaction studies, together with plant complementation experiments, suggest that the C-terminus of FRI is essential for protein function, while the N-terminus improves FRI activity. These findings provide a better understanding of how the components of the proposed "FRI-complex" may interact to promote FLC expression.

Bibliography: leaves 159-205. / xiv, 205, [23] leaves : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This research aims to improve understanding of the control of flowering in relation to photoperiod and temperature to increase knowledge of the floral initiation trigger for Banksia. An exploration of the population biology in relation to genetic variation present in commercial and natural populations of Banksia will provide information on the gene pool for breeding programs. Molecular biology techniques have been used to explore areas such as pollen competition and gene flow. / Thesis (Ph.D.)--University of Adelaide, Dept. of Horticulture, Viticulture and Oenology, 1997

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2004. / Härtill 4 uppsatser.

Diss. (sammanfattning) Umeå : Sveriges lantbruksuniv., 2006. / Härtill 4 uppsatser.

Thesis (M.S.)--University of Missouri-Columbia, 2004. / Typescript. Includes bibliographical references (leaves 119-125). Also available on the Internet.

Thesis (M.S.)--University of Missouri-Columbia, 2004. / Typescript. Includes bibliographical references (leaves 119-125). Also available on the Internet.

Made available in DSpace on 2014-06-11T19:26:41Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-06-14Bitstream added on 2014-06-13T20:34:28Z : No. of bitstreams: 1 segantini_dm_me_botfca.pdf: 1766375 bytes, checksum: c10f2414612f2c693cbe23b962ee55f6 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O conhecimento do comportamento de uma cultura em determinada região determina o sucesso da produção e a qualidade de seu produto final. Dentro deste contexto, o presente trabalho teve como objetivo avaliar a fenologia, a produção e a qualidade dos frutos dos cultivares de pessegueiro Granada, Aurora-1, Dourado-2, Aurora-3, Marli e Chiripá, enxertados sobre o porta-enxerto Okinawa, cultivados em área experimental não irrigada e conduzidos no espaçamento 6,0 x 4,0 m. O delineamento experimental utilizado foi o inteiramente casualizado, constando de 7 tratamentos (cultivares) e 3 repetições, sendo a parcela experimental representada por uma planta. O presente trabalho foi realizado de março a dezembro de 2009 na Fazenda Experimental São Manuel da Faculdade de Ciências Agronômicas da UNESP, Campus de Botucatu, localizada no município de São Manuel - SP. De acordo com os resultados obtidos é possível afirmar que, dentre os cultivares estudados, Granada é o cultivar mais precoce, apresentando florada precoce e o menor ciclo de desenvolvimento dos frutos, Chiripá é o cultivar mais tardio, apresentando florada tardia e o maior ciclo de desenvolvimento dos frutos. Os cultivares Aurora-1 e Dourado-2 são os cultivares mais produtivos e podem ser indicados para a região, os cultivares Chiripá, Marli, Granada e Douradão são os menos produtivos em São Manuel – SP e necessitam de estudos mais aprofundados sobre seu comportamento e técnicas que viabilizem seu cultivo na região. Chiripá e Marli apresentam frutos de maior massa e calibre, o cultivar Douradão apresenta frutos com melhor valor de “ratio” seguido pelos cultivares Dourado-2, Aurora-3 e Marli. Os frutos de cultivares de pêssego podem ser considerados boas fontes de compostos polifenólicos / The knowledge of a culture behavior in a certain region determines the production success and the quality of its final product. In this context, the present study aimed to assess the phenology, production and quality of fruits from the following peach cultivars: Granada, Aurora-1, Dourado-2, Aurora-3, Marli and Chiripá, grafted on the rootstock Okinawa cultured in a non-irrigated experimental area in 6.0 x 4.0 m spacing. Experimental design was completely randomize, with 7 treatments (cultivars) and 3 replicates, and the experimental plot was represented by one plant. The present work was carried out from March to December 2009 in São Manuel Experimental Farm of the School of Agronomical Sciences, UNESP, Botucatu Campus, located in São Manuel Municipality, São Paulo State, Brazil. The obtained results allowed stating that, among the studied cultivars, Granada is the earliest, presenting early flowering and the shortest fruit development cycle; Chiripá is the latest cultivar, presenting late flowering and the longest fruit development cycle. The cultivars Aurora-1 and Dourado-2 are the most productive and can be indicated for that region, whereas the cultivars Chiripá, Marli, Granada and Douradão are the least productive in São Manuel and need further studies on their behavior, as well as techniques to make their cultivation feasible in the region. Chiripá and Marli fruits have the largest mass and thickness; Douradão fruits have the best ratio value, followed by the cultivars Dourado-2, Aurora-3 and Marli. Fruits from peach cultivars can be considered good sources of polyphenolic compounds

Made available in DSpace on 2014-06-11T19:33:39Z (GMT). No. of bitstreams: 0 Previous issue date: 2005-02-17Bitstream added on 2014-06-13T19:44:36Z : No. of bitstreams: 1 sanches_fr_dr_jabo.pdf: 1374204 bytes, checksum: 5446b86a450322cb611db869699b32f8 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O objetivo do trabalho foi de observar o efeito de diferentes concentrações do ácido giberélico, de 20, 40 e 80 mg/L, aplicadas em julho, agosto, setembro e outubro; sobre o florescimento e produção da lima ácida 'Tahiti'. Foi determinada a época em que ocorriam os processos de mudança da gema vegetativa para a floral. Foram analisados cortes histológicos de gemas axilares de ramos com quatro a seis meses de idade. Pôde-se observar quando ocorriam as mudanças morfológicas no meristema apical. A análise morfológica das gemas mostrou que no período de junho a novembro foi possível encontrar com maior facilidade gemas com início de formação de sépalas. Este momento marca o começo do processo de diferenciação morfológica do meristema apical e é determinante para as aplicações de GA3. No ano de 2003, as aplicações realizadas nos meses de agosto e setembro foram as mais efetivas em reduzir o número de flores por ramo e de frutos por planta. Neste mesmo ano, os cortes histológicos mostraram que nos referidos meses podiam ser observadas com maior facilidade gemas em início de formação de sépalas. A conclusão geral é que a concentração e a época de aplicação do GA3 influenciaram na produção de flores por ramo e frutos por planta. Quando analisada conjuntamente época e concentração, os melhores resultados estiveram associados com a concentração de 80 mg/L, em agosto e setembro. / The present work was developed to evaluate the effect of gibberellic acid on the flowering and production of 'Tahiti' lime. Treatments represent a combinati among different doses (20, 40 and 80 mg/L) and time of application (July, August, September and October). To determine the best time for GA3 spray, this work evaluated the time of the transition from vegetative to floral bud. It was collected 4 and 6 months-old buds with their branches to conduct this experiment. These buds were subjected to anatomic meristem studies, evaluating the morphological changes in the apical meristem. Along the study, the period from July to November was probably the best time to find buds at the initiation process of morphological differentiation (initiation of sepals). In 2003, when GA3 application was performed, the results show that the best periods to reduce the number of flowers formed by branch and the number of fruits were August and September. In that year, the histological cuts from buds showed that in August and September it was easy to find bud with initiation of sepal formation. The conclusion is that there was significant reduction in flowering and fruit production when the concentration increased and when the favorable period to application of GA3 was chosen. The effective reduction was a combination between the concentration and time of application. The best results were obtained with application of 80 mg/L in August and September.

This work had as objectives to test different populations of the culture of cartamo, regarding the behavior of the fenology, the characteristics of the stem, the cycle and the behavior of the border plants at two cultivation periods: fall/winter and spring/summer. The populations used in the two periods were 48, 64, 80, 96, 112 and 128 pl/m2. The fall/winter cultivation corresponded to the period from 04/04/2003 to 23/08/2003 and the spring/summer cultivation corresponded to the period from 03/10/2003 to 23/12/2003. The cycle, of the emergency to the end of harvesting, lasted 142 days for the first period and 74 days for the second cultivation period. Flowering lasted langer for the fall/winter and was very short for the spring/summer cultivation. The total and partial plant height did not differ among populations in the fall/winter cultivation. However, in the spring/summer the total height presented a quadratic behavior with the increase in population and the partial height did not vary. In the fall/winter cultivation the plants presented larger values of stem diameter, branches diameter, length of branches and total number of nodes. The stem diameter, branches diameter, number and length of branches, fresh and dry matter mass decreased with the increase in population at the two cultivation times. The capitulus diameter decreased with the increase in population at the fall/winter, but at the spring/summer it decreased in the populations of 48 to 96 pl/m2 and increased in the populations of 112 to 128 pl/m2. The border plants in the fall/winter cultivation presented values of fresh matter, total and partial height, stem diameter and of branches, capitulus diameter and length of branches, higher than the observed for the plants of the interior of the flower bed. / Este trabalho teve como objetivos testar diferentes populações da cultura do cártamo, quanto ao comportamento da fenologia, as características da haste, o ciclo e o comportamento das plantas de borda em duas épocas de cultivo: outono/inverno e primavera/verão. As populações utilizadas nas duas épocas foram 48, 64, 80, 96, 112 e 128 pl/m2. O cultivo de outono/inverno correspondeu ao período de 04/04/2003 a 23/08/2003 e o cultivo de primavera/verão correspondeu ao período de 03/10/2003 a 23/12/2003. O ciclo, da emergência ao término da colheita, foi de 142 dias para a primeira e de 74 dias para a segunda época de cultivo. A duração do florescimento foi maior para o outono/inverno e muito rápido para o cultivo de primavera/verão. As alturas total e parcial não apresentaram diferenças significativas entre as populações no cultivo de outono/inverno. Já na primavera/verão a altura total apresentou comportamento quadrático com o aumento da população e a altura parcial não variou. No cultivo de outono/inverno as plantas apresentaram maiores valores de diâmetro da haste, diâmetro dos ramos, comprimento de ramos e maior número total de nós. O diâmetro da haste, diâmetro dos ramos, número e comprimento dos ramos, a massa da matéria fresca e da matéria seca decresceram com o aumento da população nas duas épocas de cultivo. O diâmetro do capítulo decresceu com o aumento da população no outono/inverno, mas na primavera/verão decresceu nas populações de 48 a 96 pl/m2 e aumentou nas populações de 112 a 128 pl/m2. As plantas de borda no cultivo de outono/inverno apresentaram valores de massa da matéria fresca, altura total e parcial, diâmetro de haste e de ramos, diâmetro de capítulo e comprimento de ramos, superiores aos observados nas plantas do interior do canteiro.