Дисертації з теми "Reserve carbohydrates"

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
O maracujá-amarelo é uma fruta de grande valor econômico e cultural no Brasil, país com a maior produção e consumo do fruto atualmente. Apesar da grande importância do fruto, a mobilização da reserva de suas sementes durante a germinação não é conhecida. Portanto, o objetivo deste trabalho foi verificar as alterações histológicas e bioquímicas ocorridas na semente durante os primeiros dez dias de germinação. Extrações de carboidratos, lipídios e proteínas foram realizadas juntamente com a análise histoquímica das sementes nos períodos de 0, 2, 4, 6, 8 e 10 dias de germinação tanto sob luz branca quanto no escuro. Os resultados mostraram que a principal reserva das sementes é lipídica, pois o seu consumo é alto durante a germinação, porém também há variações nos níveis de proteínas e carboidratos que podem estar envolvidas no processo de germinação.
The Yellow Passion fruit is of great economic and cultural value in Brazil, the country with the largest production and consumption nowadays. Despite its great importance, the mobilization of the seed reserves is unknown. Therefore, our objective was to evaluate the histological and biochemical changes that occur in the seed during the first ten days of germination. Carbohydrates, lipid and protein extractions were done along with seed histochemical analysis at 0, 2, 4, 6, 8 and 10 days of germination under continuous white light and darkness. The results showed that lipids are the main reserve, for its consumption is high during germination, but there are also variations in protein and carbohydrates levels that may be involved in the germination process.

Orientadora: Maria Célia Bertolini
Banca: Nilce Maria Martinez Rossi
Banca: Rafael Silva Rocha
Banca: Carlos Takeshi Hotta
Banca: Iran Malavazi
Resumo: The fungus Neurospora crassa, a model organism in studies of gene expression, metabolism, photobiology and circadian rhythm, is able to respond and adapt to different environmental stresses, such as heat shock, pH changes, nutrient limitation, osmotic stress, and others. Besides that, N. crassa has the genome sequenced and collections of knocked-out strains are avalaible to the scientific community. A systematic screening analysis performed with mutant strains in genes encoding transcription factors led to identify proteins involved in the glycogen metabolism regulation in this fungus. Glycogen and trehalose are storage carbohydrates that functions as a carbon and energy reserve. Trehalose can also protect membranes and proteins, increasing the tolerance to adverse conditions. In this work, some transcription factors were functionally characterized regarding their role in glycogen and trehalose metabolism regulation. The first condition investigated was the influence of the circadian clock in the glycogen metabolism. We observed that the glycogen accumulation and the expression of genes encoding glycogen synthase (gsn) and glycogen phosphorylase (gpn) are rhythmic in a wild-type strain and dependent on the FREQUENCY (FRQ) oscillator, the core component of the N. crassa circadian clock. The VOS-1 transcription factor, that is controlled by clock and can act in the connection between clock and glycogen metabolism, binds to gsn and gpn promoters rhythmically. However, the expres... (Resumo completo, clicar acesso eletrônico abaixo)
Doutor

Orientador: Massanori Takaki
Banca: Giuseppina Pace Pereira Lima
Banca: Lilian Beatriz Penteado Zaidan
Resumo: O maracujá-amarelo é uma fruta de grande valor econômico e cultural no Brasil, país com a maior produção e consumo do fruto atualmente. Apesar da grande importância do fruto, a mobilização da reserva de suas sementes durante a germinação não é conhecida. Portanto, o objetivo deste trabalho foi verificar as alterações histológicas e bioquímicas ocorridas na semente durante os primeiros dez dias de germinação. Extrações de carboidratos, lipídios e proteínas foram realizadas juntamente com a análise histoquímica das sementes nos períodos de 0, 2, 4, 6, 8 e 10 dias de germinação tanto sob luz branca quanto no escuro. Os resultados mostraram que a principal reserva das sementes é lipídica, pois o seu consumo é alto durante a germinação, porém também há variações nos níveis de proteínas e carboidratos que podem estar envolvidas no processo de germinação.
Abstract: The Yellow Passion fruit is of great economic and cultural value in Brazil, the country with the largest production and consumption nowadays. Despite its great importance, the mobilization of the seed reserves is unknown. Therefore, our objective was to evaluate the histological and biochemical changes that occur in the seed during the first ten days of germination. Carbohydrates, lipid and protein extractions were done along with seed histochemical analysis at 0, 2, 4, 6, 8 and 10 days of germination under continuous white light and darkness. The results showed that lipids are the main reserve, for its consumption is high during germination, but there are also variations in protein and carbohydrates levels that may be involved in the germination process.
Mestre

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
O objetivo deste trabalho foi avaliar respostas do capim-tifton 85 a doses de nitrogênio (N) associadas a doses e fontes de boro (B). Em casa de vegetação, conduziu-se um experimento fatorial 3 ´ 3 ´ 3 {três doses de N (0, 100 e 200 mg kg–1), três doses de B (0, 1,3 e 2,6 mg kg–1) e três fontes de B [colemanita fundida ao termofosfato (CF), colemanita em mistura com termofosfato (CM) e ácido bórico (H3BO3)]} em delineamento inteiramente ao acaso. As plantas cresceram em vasos preenchidos com amostra de um Latossolo Vermelho distrófico. Elas foram avaliadas em três ciclos de crescimento. O N foi aplicado no início de cada ciclo e o B apenas antes do plantio. A aplicação de N aumentou a massa seca da parte aérea e o número de perfilhos do capim nos três ciclos. A aplicação de B, isolada ou associada à de N, não teve influência nesses atributos, embora o solo tivesse baixo teor de B disponível. O suprimento de N aumentou também os teores de carboidratos de reserva na raiz da planta nos dois ciclos em que foram avaliados (primeiro e terceiro). O suprimento de B aumentou o teor desses carboidratos na base do caule no primeiro ciclo. Os fornecimentos de N e B aumentaram seus respectivos teores na parte aérea do capim no três ciclos, exceto no caso do teor de B no terceiro ciclo. Todas as fontes de B aumentaram o teor de B disponível no solo, mas a CM e o H3BO3 aumentaram mais do que a CF. O efeito mais evidente da aplicação conjunta de N e B ocorreu no acúmulo de B na parte aérea da planta, aumentando mais com a combinação das duas aplicações. O teor inicial de B no solo (0,15 mg dm–3) foi suficiente para atender as necessidades do capim-tifton 85 nos três ciclos de crescimento.
The objective of this work was to evaluate responses of Tifton 85 bermudagrass to nitrogen (N) rates associated with boron (B) rates and sources. In greenhouse, it was carried out a factorial experiment 3 ´ 3 ´ 3 {three N rates (0, 100 and 200 mg kg–1), three B rates (0, 1.3 and 2.6 mg kg–1) and three B sources [colemanite fused to termophosphate (CF), colemanite in mixture with termophosphate (CM) and boric acid (H3BO3)]} in complete randomized design. The plants grew in pots filled with sample of a Typic Haplustox. They were evaluated during three growth cycles. The N was applied at the beginning of each cycle and the B just before the planting. The N application increased both top dry mass and tiller number of the grass in the three cycles. The B application, isolated or associated with N application, did not have influence on these attributes, though the soil had low available B content. The N supply increased reserve carbohydrates contents in plant root in the two cycles in which they were evaluated (first and third). The B supply increased the content of these carbohydrates in the stem base in the first cycle. The N and B furnishings increased their respective contents in top grass in the three cycles, except in the case of the B content in the third cycle. All the sources increased the available B content in soil, but CM and H3BO3 increased more than CF. The most evident effect of the N and B applications together occurred in the B accumulation in top plant, increasing more with the combination of the two applications. The initial B content in soil (0.15 mg dm–3) was enough to attend necessities of Tifton 85 bermudagrass in the three growth cycles.

Resumo: O objetivo deste trabalho foi avaliar respostas do capim-tifton 85 a doses de nitrogênio (N) associadas a doses e fontes de boro (B). Em casa de vegetação, conduziu-se um experimento fatorial 3 ' 3 ' 3 {três doses de N (0, 100 e 200 mg kg-1), três doses de B (0, 1,3 e 2,6 mg kg-1) e três fontes de B [colemanita fundida ao termofosfato (CF), colemanita em mistura com termofosfato (CM) e ácido bórico (H3BO3)]} em delineamento inteiramente ao acaso. As plantas cresceram em vasos preenchidos com amostra de um Latossolo Vermelho distrófico. Elas foram avaliadas em três ciclos de crescimento. O N foi aplicado no início de cada ciclo e o B apenas antes do plantio. A aplicação de N aumentou a massa seca da parte aérea e o número de perfilhos do capim nos três ciclos. A aplicação de B, isolada ou associada à de N, não teve influência nesses atributos, embora o solo tivesse baixo teor de B disponível. O suprimento de N aumentou também os teores de carboidratos de reserva na raiz da planta nos dois ciclos em que foram avaliados (primeiro e terceiro). O suprimento de B aumentou o teor desses carboidratos na base do caule no primeiro ciclo. Os fornecimentos de N e B aumentaram seus respectivos teores na parte aérea do capim no três ciclos, exceto no caso do teor de B no terceiro ciclo. Todas as fontes de B aumentaram o teor de B disponível no solo, mas a CM e o H3BO3 aumentaram mais do que a CF. O efeito mais evidente da aplicação conjunta de N e B ocorreu no acúmulo de B na parte aérea da planta, aumentando mais com a combinação das duas aplicações. O teor inicial de B no solo (0,15 mg dm-3) foi suficiente para atender as necessidades do capim-tifton 85 nos três ciclos de crescimento.
Abstract: The objective of this work was to evaluate responses of Tifton 85 bermudagrass to nitrogen (N) rates associated with boron (B) rates and sources. In greenhouse, it was carried out a factorial experiment 3 ' 3 ' 3 {three N rates (0, 100 and 200 mg kg-1), three B rates (0, 1.3 and 2.6 mg kg-1) and three B sources [colemanite fused to termophosphate (CF), colemanite in mixture with termophosphate (CM) and boric acid (H3BO3)]} in complete randomized design. The plants grew in pots filled with sample of a Typic Haplustox. They were evaluated during three growth cycles. The N was applied at the beginning of each cycle and the B just before the planting. The N application increased both top dry mass and tiller number of the grass in the three cycles. The B application, isolated or associated with N application, did not have influence on these attributes, though the soil had low available B content. The N supply increased reserve carbohydrates contents in plant root in the two cycles in which they were evaluated (first and third). The B supply increased the content of these carbohydrates in the stem base in the first cycle. The N and B furnishings increased their respective contents in top grass in the three cycles, except in the case of the B content in the third cycle. All the sources increased the available B content in soil, but CM and H3BO3 increased more than CF. The most evident effect of the N and B applications together occurred in the B accumulation in top plant, increasing more with the combination of the two applications. The initial B content in soil (0.15 mg dm-3) was enough to attend necessities of Tifton 85 bermudagrass in the three growth cycles.
Orientador: Edson Luiz Mendes Coutinho
Coorientador: Edemo João Fernandes
Banca: Mara Cristina Pessôa da Cruz
Banca: Cassio Hamilton Abreu Junior
Banca: Takashi Muraoka
Banca: Renato de Mello Prado
Doutor

‘Crimson Seedless’ (Vitis vinifera L.) is an attractive, late season, red, seedless cultivar, which is currently a very popular table grape cultivar. It is one of the most planted cultivars in South Africa and third in terms of total area of table grape vineyards in production. Mature ‘Crimson Seedless’ grapes are characterized by outstanding eating quality, good flavour, firm and crisp berries. One of the key factors affecting the yield of table grape cultivars is bud fruitfulness. Low fruitfulness can have a significant effect on the yield of table grape cultivars and ‘Crimson Seedless’ is characterized by a fruitfulness problem. Summer pruning, such as the removal of shoots after harvesting grapes, is a cultivation practice widely used by some table grape producers in the Orange River region of South Africa. The first hypothesis of this study stated that the removal of shoots after harvest will increase the transmitted PAR through the canopy, increase carbohydrate reserve levels in canes and improve bud fruitfulness of ‘Crimson Seedless’. A second hypothesis of this study stated that the cut back of all main shoots and shoots developing from spurs to the nearest lateral shoot and the removal of all unproductive shoots after berry set will result in fruitful shoots the following season. The third and final hypothesis of this study stated that the removal of shoots after harvest and berry set will improve the yield and quality of Vitis vinifera cv. ‘Crimson Seedless’. The study was conducted over three seasons (2010/11 to 2012/13) and aimed at investigating factors, including shoot removal, impacting bud fruitfulness of an 11-year-old commercial V. vinifera L. cv. ‘Crimson Seedless’ vineyard, grafted on ‘Ramsey’ (Vitis champinii) rootstocks in the Hex River Valley. The treatment design was a complete randomized design and involved five treatments, which included 33% shoot removal (S33) and 66% shoot removal (S66) after harvest, cutting of all main and lateral shoots developing from spurs to the nearest lateral shoot (LS), removal of all unproductive shoots (RSB) which was compared with the control, in which standard pruning practices were performed. The results obtained in this experiment showed that shoot removal after harvest and after berry set improves PAR transmission into the canopy, but there was no significant impact on bud fruitfulness. In addition, it was found that shoot removal reduced vegetative growth resulting in thinner canes that also led to the improvement in PAR transmission. Furthermore, bunch number per shoot in the LS treated vines was reduced when compared with S33 treated vines, illustrating that shoot removal at berry set can reduce bunch number per shoot due to defoliation after berry set. The significant decrease in bud burst in the S33 treatments compared with the control was expected due to less shoots, resulting in a reduction in cane mass during the 2010/11 season. The significant effect of LS treatments after berry set on TSS and total red pigments compared with the S66 treatments and the control, respectively, clearly indicates that shoot removal after berry set improves grape colour. The positive effect of LS treatments on colour was supported by the significant improvement in class 4 bunches, representing an improvement in quality. Although shoot removal did not have a significant effect on the bunch mass per vine of ‘Crimson Seedless’, there was a significant reduction in total bunches for export and mass of the total export bunches in the LS treatments in the 2011/12 season. A link between carbohydrate concentration in canes and bud fruitfulness was not found in this study, as S33 and S66 treatments did not have a significant effect on carbohydrate content in canes during the 2011/12 season. The question therefore arises whether the treatments applied during the growing seasons are worthwhile, because there was no significant impact on bud fruitfulness of Vitis vinifera L. cv. ‘Crimson Seedless’. This study illustrates that growers need to decide whether it is worthwhile to utilize labour for this practice and they must manage grapevines not only for the current seasons crop, but also for the next season and this can be accomplished by maintaining sufficient carbohydrates for fruitfulness and yield from season to season.
Dissertation (MInst Agrar)--University of Pretoria, 2014.
tm2015
Plant Production and Soil Science
MInst Agrar
Unrestricted

Viticultural practices such as trunk girdling and shoot topping along with defoliation, shading and node number per vine treatments were used to alter the carbohydrate physiology of mature Chardonnay grapevines growing in the cool climate of Canterbury, New Zealand. The timing of vine defoliation in the season previous to fruiting decreased concentrations of over-wintering carbohydrate reserves (mostly starch) in both the trunks and roots of grapevines. Roots were particularly sensitive, with defoliation as early as 4 weeks after bloom in the previous season reducing starch concentrations to 1.5%Dwt at bud burst compared with 17%Dwt in non-defoliated vines. In contrast, partial vine defoliation as early as bloom in the previous season reduced root starch concentrations to 4-7%Dwt at bud burst compared with 15%Dwt in non-defoliated vines. Vine shading and trunk girdling treatments at bloom in the previous season, resulted in small reductions in root starch concentrations (16%Dwt) compared with non-shaded and non-girdled vines (19%Dwt), but shoot topping did not. Study across three growing seasons established that higher concentrations of over-wintering trunk and root carbohydrate reserves were associated with warmer and sunnier weather in the previous growing season. Individual shoot leaf removal at either the beginning or towards the end of the inflorescence initiation period, reduced shoot starch concentrations to 3-6%Dwt compared with 11 %Dwt for no leaf removal, such reductions persisted through to the following season. Shoot topping at the start of the initiation period had no effect on shoot carbohydrate accumulation, but trunk girdling temporarily increased shoot starch concentrations during the first 31 days after treatment. Reductions in over-wintering trunk and root carbohydrate reserves were associated with a reduction in inflorescences per shoot and flowers per inflorescence in the following season, the reduction as much as 50% compared with non carbohydrate stressed vines. While there were strong linear or curvilinear relationships between the concentration of starch in trunks and roots at bud burst and inflorescences per shoot and flowers per inflorescence, in case the of inflorescences per shoot, there was not an immediate cause and effect because inflorescences were initiated in the previous season. Individual shoot leaf removal during the inflorescence initiation period illustrated that leaf removal directly inhibited the initiation of inflorescences in latent buds. Shoot carbohydrate measurements showed a strong curvilinear relationship to the number of inflorescences per shoot, with a threshold starch concentration of 10-12%Dwt during the inflorescence initiation period required for a maximum number of inflorescences per shoot. Furthermore, examination of individual node positions emphasised the importance of the subtending leaf on the initiation of inflorescences within the latent bud. The number of inflorescences per shoot post bud burst was reduced on vines that were both carbohydrate reserve stressed (by previous season's defoliation) and had a high node (108) number retained per vine after winter pruning compared with little or no reduction in inflorescences per shoot on carbohydrate reserve stressed vines that had a low (20) node number per vine. The reduction in inflorescences per shoot on high node vines was associated with reduced carbohydrate reserves and reduced shoot vigour (thinner and lighter shoots). Flowers per inflorescence were reduced by as much 50% in response to lower overwintering carbohydrate reserves. Fewer flowers per inflorescence were attributed to a reduction in primary branching of the inflorescence and also a reduction in flowers per branch. Strong linear relationships between the concentrations of starch in trunks and roots and flowers per inflorescence indicate that the determination of flowers per inflorescence, unlike inflorescences per shoot, may be dependent on the level of overwintering carbohydrate reserves. This is most likely due to changes in branching of the inflorescence and individual flower formation occurring during the bud burst period. Per cent fruitset was not affected by reductions in carbohydrate reserves, so fewer inflorescences per shoot and flowers per inflorescence resulted in reduced vine yield. The findings of this thesis indicate that changes in the level of carbohydrate production and partitioning in response to a range of viticultural management practices and seasonal weather contribute to seasonal variation in grapevine flowering and yields in New Zealand's cool climate environment. The relationships between carbohydrate reserves and flowering illustrate the potential to use this information to predict grapevine flowering and forecast yields. The practical implications of this research illustrate that the viticulturist must manage grapevines not only for the current crop, but also for subsequent crops by maintaining sufficient carbohydrate reserves for balanced growth flowering and fruiting from season to season.

A frequência ideal de pastejo em gramíneas tropicais é aquela associada com a interrupção da rebrotação quando o dossel forrageiro atinge 95% de interceptação da luz incidente (IL). Leguminosas forrageiras tropicais, particularmente o amendoim forrageiro, apresentam elevado potencial de uso, especialmente pela habilidade de fixar N2 atmosférico. Contudo, informações acerca de suas respostas sob condições de pastejo são escassas. O objetivo deste estudo foi avaliar as respostas agronômicas, as reservas orgânicas de C e N e a fixação biológica de N do amendoim forrageiro (Arachis pintoi cv. Belmonte) sob condições de pastejo. No caso das avaliações de fixação biológica de N, foram conduzidos dois experimentos, um sob lotação contínua e outro sob lotação intemitente (pastejo rotativo). Durante o período que antecedeu cada um dos experimentos (entre 60 e 90 dias) os piquetes foram submetidos aos tratamentos de pastejo para adaptação. Para o experimento de lotação intermitente os tratamentos corresponderam a combinações entre duas condições pré- (95% e máxima interceptação de luz durante a rebrotação - IL95% e ILMáx, respectivamente) e duas condições pós-pastejo (alturas pós-pastejo correspondentes a 40 e 60% da altura pré-pastejo) alocados às unidades experimentais segundo arranjo fatorial 2x2 e delineamento de blocos completos casualizados, com quatro repetições. Para o experimento de lotação contínua os tratamentos corresponderam a quatro alturas de manejo (5, 10, 15 e 20 cm) mantidas constantes ao longo de todo o período experimental. As avaliações foram realizadas ao longo de todo o ano, em épocas predeterminadas. Sob lotação intermitente, pastos manejados com a meta IL95% apresentaram menor altura pré-pastejo (13,3 cm) relativamente a pastos manejados com a meta ILMáx (18,5 cm), assim como menor acúmulo de estolão durante a rebrotação, porém sem diferença em acúmulo de forragem. Variações estacionais nas respostas agronômicas estiveram associadas ao ciclo anual de desenvolvimento das plantas e sua estratégia para otimizar recursos energéticos, evento conhecido como segmentação. Ao contrário da maioria dos relatos apresentados na literatura, pastejos frequentes (IL95%) e severos (40% da altura pré-pastejo) sob lotação intermitente ou mais intensos sob lotação contínua (alturas de manejo de 5 e 10 cm) não ocasionaram impactos negativos sobre o sistema radicular e o processo de nodulação. Contudo, maiores valores de nitrogênio oriundo da fixação biológica (%Ndda ) e a FBN (kg ha-1 N) foram obtidos em pastos manejados com estratégias de manejo de intensidade de pastejo moderada a leniente, caracterizadas por valores maiores de biomassa da parte aérea (IAF médio) independente do método de pastejo empregado. As reservas orgânicas de carbono (C) e nitrogênio (N) apresentaram variações ao longo do ano. De forma geral, períodos menos propícios ao crescimento e desenvolvimento da espécie (outono/inverno e início de primavera) apresentaram acúmulo de CHO\'s e nitrogênio solúvel tanto em concentração como em quantidade (pool). Independentemente do método de pastejo considerado, lotação contínua e lotação intermitente, as respostas avaliadas apresentaram como ponto comum a luz e suas relações, uma vez que quando avaliadas em função da biomassa áerea média ou IAF médios seguiram um mesmo continuum de variação. Intensidade de pastejo moderada a leniente parece ser a mais indicada para o manejo do amendoim forrageiro sob pastejo.
The ideal grazing frequency of tropical forage grasses is associated with the interruption of regrowth when sward canopy intercepts 95% of the incident light (LI). Tropical forage legumes, particularly forage peanut, have a high potential of use, specialy due to their ability to fix nitrogen from the atmosphere. However, information about their responses under grazing are scarse. The objective of this study was to evaluate the agromic responses, C and N organic reserves and nitrogen biological fixation (NBF) of forage peanut (Arachis pintoi cv. Belmonte) under grazing. For measurements regarding NBF, two experiments were carried out, one under continuous and other under intermitent stocking (rotational grazing). Prior to the beginning of the experiments (between 60 and 90 days), paddocks were subjected to the grazing treatments for adaptation purposes. For the intermitent stocking experiment, treatments corresponded to combinations between two pre- (95% and maximum canopy light interception during grazing - LI95% and LIMax, respectively) and two post-grazing conditions (post-grazing heights equivalent to 40 or 60% of the pre-grazing height). For the continuous stocking experiment, treatments corresponded to four grazing intensities represented for sward management heights of 5, 10, 15 and 20 cm. The experimental design was the same, a randomized complete block with four replications. Measurements were carried out throughout the year, in pre-determined seasons. Under intermitent stocking, swards managed with the LI95% target were shorter (13.3 cm) than those managed with the LIMax target (18.5 cm), and accumulated less stolon during regrowth, although with no difference in herbage accumulation. Seasonal variations in agronomic responses were associated with the annual cycle of plant development and strategy for optimizing energy use, an event known as segmentation. Contratry to the majority of reports in the literature, frequent (LI95%) and severe (post-grazing height equivalente to 40% of the pré-grazing height) grazings under intermitent stocking or intense grazing under continuous stocking (management heights of 5 and 10 cm) did not cause negative impacts on root mass and nodulation. However, greater values of nitrogen originated from biological fixation (%Ndda ) and NBF (kg ha-1 N) were recorded on swards managed with moderate to lenient grazing intensities, characterized by greater values of aerial biomass (average LAI) regardless of the grazing method used. C and N organic reserves varied throughout the year. In general, there was an accumulation of soluble carbohydrates and nitrogen (concentration and pool) during periods of limited availability of climatic growth factors (autumn/winter and early spring). Independent of grazing method, continuous or intermitent stocking, plant responses had their variability well associated with light and its relations, since when ploted against average aerial biomass or LAI followed the same continuum of variation. Moderate to lenient grazing intensity seems to be the most adequate for managing forage peanut under grazing.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
O trabalho teve como objetivo avaliar, a viabilidade da metodologia para avaliação da translocação e alocação de fotoassimilados, utilizando o isótopo estável do carbono-13 como marcador, assim como, avaliar a relação fonte-dreno nos diferentes órgãos bem como, saber em que órgão se encontraria o carbono-13 após determinados intervalos de tempo, em plantas em estádio reprodutivo da espécie Ficus carica L. Para tanto, uma folha da figueira considerada adulta através da caracterização fotossintética com um medidor portátil de fotossíntese IRGA-6400, foi colocada dentro de uma câmara de acrílico construída para este fim, e submetida a um ambiente com enriquecimento de 13CO2 por 30 minutos. Após 24 horas, os diferentes órgãos presentes nas plantas foram coletados no experimento órgãos drenos, nas demais plantas seguiu-se a experimentação tempo de alocação, onde as plantas de Ficus carica L. foram arrancadas ao longo das horas: 6, 24, 48, 72, 120, 168, 360. Após o tempo especificado as partes (meristema apical, folhas, ramos, caule e sistema radicular) das plantas em estudo foram coletados e imediatamente imersos em nitrogênio líquido (-196 ºC), para evitar que os tecidos permanecessem vivos e conseqüentemente pudessem consumir os fotoassimilados no processo da respiração. As amostras, previamente identificadas foram secas em estufa de circulação forçada a 65º C por 72 horas, em seguida moídas em moinho criogênico, para que houvesse uma perfeita homogeneização, sendo posteriormente analisadas no espectrômetro de massas de razão isotópica, para a determinação do enriquecimento relativo de 13C. Naturalmente a planta apresenta valores de enriquecimento relativo de 13C - 27,92‰, alocando acima de 90% da massa seca e do carbono total nas partes lenhosas. Os resultados obtidos indicaram que figueira se caracteriza como uma planta do ciclo...
The work have planned be quizzed, the feasability of the methodology for evaluation of the fhotosynthates translocation and allocation, using the carbon 13 stable isotope a marker, evaluate the source-sink relation in the different organs and, know in that organ would be found the carbon-13 after determined time periods, in Ficus carica L. plants in reproductive stadium. A fig tree leaf considered adult through the photosynthetic with a portable meter of photosynthesis IRGA-6400 characterization. Was put inside a acrylic chamber, and submitted to an environment with 13CO2 enrichment for 30 minutes. After 24 hours, the different organs present in the plants were collected in the drains organs experiment, in the other plants followed the allocation time experimentation where the plants of Ficus carica L. were lurches to the long one of the hours: 6, 24, 48, 72, 120, 168, 360. After the time specified the studied plant parts (meristem, sheets, branches, stem and system roots) were collected and immediately immersed in liquid nitrogen (-196 ºC), for avoid that the fabrics remained alive and consequently could consume the fhotosynthates in the breath trial. The samples, previously identified were droughts in of circulation forced to 65º C for 72 hours, right away ground in cryogenic mill, for that had a perfect homogenization, being subsequently analyzed in the mass spectrometry of isotopic reason, for the relative enrichment... (Complete abstract click electronic access below)

Resumo: O trabalho teve como objetivo avaliar, a viabilidade da metodologia para avaliação da translocação e alocação de fotoassimilados, utilizando o isótopo estável do carbono-13 como marcador, assim como, avaliar a relação fonte-dreno nos diferentes órgãos bem como, saber em que órgão se encontraria o carbono-13 após determinados intervalos de tempo, em plantas em estádio reprodutivo da espécie Ficus carica L. Para tanto, uma folha da figueira considerada adulta através da caracterização fotossintética com um medidor portátil de fotossíntese IRGA-6400, foi colocada dentro de uma câmara de acrílico construída para este fim, e submetida a um ambiente com enriquecimento de 13CO2 por 30 minutos. Após 24 horas, os diferentes órgãos presentes nas plantas foram coletados no experimento órgãos drenos, nas demais plantas seguiu-se a experimentação tempo de alocação, onde as plantas de Ficus carica L. foram arrancadas ao longo das horas: 6, 24, 48, 72, 120, 168, 360. Após o tempo especificado as partes (meristema apical, folhas, ramos, caule e sistema radicular) das plantas em estudo foram coletados e imediatamente imersos em nitrogênio líquido (-196 ºC), para evitar que os tecidos permanecessem vivos e conseqüentemente pudessem consumir os fotoassimilados no processo da respiração. As amostras, previamente identificadas foram secas em estufa de circulação forçada a 65º C por 72 horas, em seguida moídas em moinho criogênico, para que houvesse uma perfeita homogeneização, sendo posteriormente analisadas no espectrômetro de massas de razão isotópica, para a determinação do enriquecimento relativo de 13C. Naturalmente a planta apresenta valores de enriquecimento relativo de 13C - 27,92‰, alocando acima de 90% da massa seca e do carbono total nas partes lenhosas. Os resultados obtidos indicaram que figueira se caracteriza como uma planta do ciclo... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The work have planned be quizzed, the feasability of the methodology for evaluation of the fhotosynthates translocation and allocation, using the carbon 13 stable isotope a marker, evaluate the source-sink relation in the different organs and, know in that organ would be found the carbon-13 after determined time periods, in Ficus carica L. plants in reproductive stadium. A fig tree leaf considered adult through the photosynthetic with a portable meter of photosynthesis IRGA-6400 characterization. Was put inside a acrylic chamber, and submitted to an environment with 13CO2 enrichment for 30 minutes. After 24 hours, the different organs present in the plants were collected in the drains organs experiment, in the other plants followed the allocation time experimentation where the plants of Ficus carica L. were lurches to the long one of the hours: 6, 24, 48, 72, 120, 168, 360. After the time specified the studied plant parts (meristem, sheets, branches, stem and system roots) were collected and immediately immersed in liquid nitrogen (-196 ºC), for avoid that the fabrics remained alive and consequently could consume the fhotosynthates in the breath trial. The samples, previously identified were droughts in of circulation forced to 65º C for 72 hours, right away ground in cryogenic mill, for that had a perfect homogenization, being subsequently analyzed in the mass spectrometry of isotopic reason, for the relative enrichment... (Complete abstract click electronic access below)
Orientador: Sarita Leonel
Coorientador: Carlos Ducatti
Banca: João Domingos Rodrigues
Banca: Marco Antonio da Silva Vasconcellos
Mestre

Resumo: O objetivo do trabalho foi estudar as características morfogenéticas e estruturais do capim-Tanzânia, a produção de forragem, as perdas de nitrogênio (N) por volatilização, reservas orgânicas e a avaliação do sistema radicular sob doses de nitrogênio sob pastejo. O experimento foi instalado na área Fazenda Experimental de Iguatemi da Universidade Estadual de Maringá, no período de março de 2007 a março de 2008. O delineamento experimental utilizado foi de blocos completos ao acaso, com parcelas subdivididas com quatro repetições. Nas parcelas, encontravam-se as doses de N (0, 150, 300 e 450 kg ha-1 de N) e, nas sub-parcelas, as estações do ano. As perdas de N por volatilização foram quantificadas depois da adubação N (1, 2, 3, 6, 9, 12 e 15 dias). As amostragens das raízes foram realizadas nas profundidades de 0-10, 10-20 e 20-40 cm. A aplicação do fertilizante N na pastagem foi parcelada em três aplicações. A produção de massa seca total e de lâmina foliar de forragem respondeu linearmente até 282 kg ha-1 de N na estação do verão. A adubação nitrogenada exerce efeito positivo nas taxas de alongamento e aparecimento foliar, e no número de folhas vivas em plantas de capim-Tanzânia nas estações da primavera e verão. Elevadas adubações nitrogenadas associada a intervalos menores de pastejo promovem uma maior porcentagem de lâmina foliar; no manejo de pastos de capim-Tanzânia sob lotação rotacionada com altura de 70 cm na entrada dos animais para o pastejo e saída com 30 cm de altura do resíduo. A interação entre o nível de adubação e o período depois da aplicação de uréia foi significativa para a variável volatilização acumulada de N-NH3. A aplicação da uréia acarreta perdas percentuais mais elevadas de N nos três primeiros dias após a aplicação. A perda média acumulada de N-NH3 no período para as três estações do ano... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The present research project had for objectives to study the variables morphogenesis and structural of grass-Tanzania, the forage production, the losses of nitrogen for volatilization, organic reserves and the evaluation of the system root under the effect of levels of nitrogen under grazing. The experiment was installed in the area Experimental Finance of Iguatemi of the State University of Maringá among April of 2007 to March of 2008. The used a completely randomized design, with plots subdivided with four repetitions. In the plots, they were the doses of N (150, 300 and 450 kg ha-1 of N) and, in the subplots, the season. The losses of nitrogen for volatilization the subplots by the time after fertilization (1, 2, 3, 6, 9, 12 and 15 days). The samplings of the roots were accomplished in the depths of 0-10, 10-20 and 20-40 cm. The application of the fertilizer N in the pasture was parceled in three applications. The production of total dry mass and of sheet to foliate of forage answered lineally to 282 kg ha-1 of N in the station of the summer. The fertilization nitrogen exercises positive effect in the prolongation taxes and emergence to foliate, and in the number of live leaves in plants of Tanzaniagrass in the stations of the spring and summer. Elevated fertilization nitrogen associated to smaller intervals of grazing promote a larger sheet percentage to foliate; in the handling of pastures of Tanzaniagrass under capacity rotation with height of 70 cm in the entrance of the animals for the grazing and exit with 30 cm of height of the residue. The interaction between level of fertilization and the period after the urea application was significant for the variable accumulated volatilization of NH3-N. The application of urea fertilizer in the pasture carries the highest percentage losses of N in the first three days after the application. The average cumulative loss of NH3-N... (Complete abstract click electronic access below)

Leafy vegetables, lettuce (Lactuca sativa L. cv. Green Oakleaf), pak choi (Brassica sinensis L. cv. Oriental Taisai) and rocket (Eruca sativa L.), were planted in an open field at Lincoln University on January 2005. Plants were harvested at 5 cm cutting height above the growing point with three different harvest start times, early start (ES), mid start (MS) and late start (LS) of harvest respectively. There were three harvests during the growing season with a 4-week interval between harvests. Generally, lettuce produced significantly higher total FW/plant (208 g) than pak choi or rocket (123 and 102 g total FW/plant, respectively). Lettuce also produced significantly higher total FW/plant than pak choi or rocket in each treatment. Lettuce produced significantly more total saleable leaf FW/plant in the ES, MS and LS treatment (137.5, 120.9 and 169.3 g FW/plant), compared with pak choi (52.9, 100 and 92 g FW/plant) or rocket (31.5, 92.2 and 56.4 g FW/plant). Pak choi produced higher total saleable leaf FW/plant than rocket in the ES and LS treatments, but a similar total saleable leaf FW/plant in the MS treatment. The best time to start harvesting was the LS treatment for lettuce, while pak choi and rocket produced better yields in the MS and LS treatments. Results for total DW/plant showed that different harvest start times did not affect the total DW/plant in lettuce. However, pak choi and rocket produced less total DW/plant in the ES treatment compared to the MS or LS treatments. This was due to a faster recovery by lettuce. In addition, lettuce produced significantly higher DW/plant during regrowth at the second and third harvests than pak choi or rocket, even though it was significantly lower at the first harvest. It is likely that after harvesting greater carbohydrate reserves and greater remaining leaf area produced greater regrowth potential in lettuce. These results suggest that lettuce has the most regrowth potential, while rocket has more than pak choi in this reaping and regrowth system. When plants were harvested at the same cutting level, lettuce had the most remaining leaf area of the three species. This remaining leaf area for lettuce could be another reason for faster recovery and more regrowth potential. More reserves and remaining leaf area may also be the reason for more regrowth potential in rocket compared to pak choi. Another important reason for the better performance of lettuce was that temperatures during the growing season were in the range of optimum temperatures (12-21 ºС), except for the regrowth between the second and third harvests in the LS. This relates to higher photosynthetic rates and in turn leads to faster recovery and regrwoth. Lettuce was the most suitable crop in the reaping and regrowth system in this experiment. However, rocket might also be appropriate for this system, particularly if the price is high enough to make it economically viable.

Le port arborescent ou buissonnant du chataignier depend des interactions entre les territoires de l'axe et des bourgeons. Le ph intracellulaire est un bon marqueur du sens du flux de nutriments. Les reserves amylacees et l'enrichissement de la seve brute en sucres solubles influencent la reprise d'activite apicale

On montre que la resistance du ble a la contrainte hydrique est associee au maintien d'un nombre d'epis fertiles et d'un nombre de grains par epi eleves, a une petite taille du grain et a une capacite de recuperation elevee. On a evalue les besoins globaus optima en eau a 440 mm et on a montre qu'une mauvaise efficacite de l'utilisation de l'eau peut etre la consequence d'un developpement foliaire surdimensionne. Une production en grains stable en cas de carence hydrique est liee a une photosynthese globale elevee, a de grandes capacites d'accumulation et de mobilisation der reserves glucidiques. Les mecanismes de resistance differant d'une variete a l'autre, on tente de definir un ideotype de ble adapte aux zones arides

Examen de l'action de la temperature, de la lummiere et de traitements par la gibberelline sur la germination des graines de cyclamen. Developpement de la plantule et formation du tubercule au niveau de l'hypocotyle. Etude biochimique de l'utilisation des reserves et de la synthese d'amidon et de glucofructosanes dans le tubercule

(1,3;1,4)-β-Glucans, which have many health benefits, represent the major cell wall component in barley endosperm. There have been a number of studies that have altered the amount of (1,3;1,4)-β-glucan in the grain, however, the effects of modifying (1,3;1,4)-β-glucan on various carbohydrate metabolic pathways and its impact on grain development have not previously been clearly defined. Here, we used transgenic grain with increased (1,3;1,4)-β-glucan and a (1,3;1,4)-β-glucanless (bgl) mutant (OUM125) supplied by Professor K. Sato (Okayama University), to investigate the link between carbohydrate metabolism and grain development in hull-less barley. Hull-less barley was investigated as it is more suitable for food use due to absence of maternal (husk) tissues. High (1,3;1,4)-β-glucan barley grain (cv Torrens) was successfully generated by over-expressing HvCslF6, via agrobacterium-mediated transformation. Transgenic grain had up to 70% more (1,3;1,4)-β-glucan than the wild type. Examination of developing transgenic grain revealed a large fluid filled cavity in the endosperm, which resulted in shrunken grain at maturity. The endosperm transfer region of the developing grain was ruptured by 10 days after pollination (DAP), which became more pronounced through development. Quantitative real-time PCR (QPCR) analysis uncovered genes related to cell wall, starch, sucrose and fructan biosynthesis that were differentially expressed across grain development. Starch metabolic genes were downregulated in the early storage phase and the fructan biosynthetic gene, 6-SFT, was upregulated during the later storage phase. Increased amounts of sucrose and fructan were found in the cavity and endosperm tissue of the transgenic grain. The link between altered sugar homeostasis, the large endosperm cavity and the poorly formed endosperm transfer region in transgenic grain was explored by immuno-histochemical microscopy. Cell walls in the endosperm transfer region were poorly formed and variations occurred in the abundance of mannan polysaccharides. Additionally, the development of both the subaleurone and aleurone layers were altered with regards to cell number, shape and position. To further understand the relationship between cell wall, starch and fructan metabolism in barley, transcript profiles of genes related to their metabolism were examined in the (1,3;1,4)- β-glucanless OUM125 mutant. Inactive CSLF6 synthase activity in OUM125 resulted in upregulation of the CslH1 gene from 19 DAP, resulting in traces of BG1 antibody labelling in the mutant pericarp. Other cell wall-related genes including CslF3, CslF7, CslF10, CesA2, CesA3 and Gsl2 were upregulated from 15 DAP in the mutant grain. Deposition of arabinoxylan, callose and cellulose was altered in the absence of (1,3;1,4)-β-glucan in the mutant endosperm. QPCR analysis identified changes in the expression of starch and fructan biosynthetic genes during the storage phase. At grain maturity, sucrose and fructan contents had increased, while the amount of starch remained unchanged. Research findings from this project provide fundamental knowledge about carbon partitioning in grain across development and suggest that small changes in polysaccharide synthesis and deposition can have significant effects on other metabolic processes important for correct grain development. While decreasing the amount of (1,3;1,4)-β-glucan in the barley endosperm had a low impact on grain morphology and carbon partitioning, significantly increasing the (1,3;1,4)-β-glucan content had major deleterious effects on a number of key processes.
Thesis (Ph.D.) (Research by Publication) -- University of Adelaide, School of Agriculture, Food and Wine, 2018

In the Northeast, land managers are combating the deleterious effects that invasive plants have on other species and natural communities with attempts to remove them or substantially reduce their density. Control methods vary depending on the target species' growth form, the extent of the invasion, and other species and resources at the site. Mechanical treatment, prescribed fire, hand-pulling, and application of herbicides, alone or in combination, have all been used to attempt control. Woody invasive plants are often difficult to eliminate due to their ability to sprout from stems, stumps, and roots. Successful control of these species requires understanding temporal variations in their below-ground resources. Total non-structural carbohydrate (TNC) reserves in the roots of woody species support growth following disturbance and generally follow an annual cycle of depletion and replenishment. This study evaluates the effectiveness of treatments when applied during periods of decreased TNC reserves. Treatments were applied to seven invasive shrubs (Corpus racemosa, Rhamnus cathartica, Rosa multiflora, Berberis thunbergii, Lonicera morrowii, Smilax rotundifolia, and Cytisus scoparius) at three different sites in Massachusetts and New York. Treatments included cutting and/or burning, applied singly or in combination, in either the dormant or growing seasons. TNC were depleted following all treatments. Dormant-season-treated plants, whether cut or burned, sprouted and replenished their reserves within the following growing season. For growing-season-treated plants TNC remained depleted longer, with a greater effect on plants that received more treatments. For most species studied, TNC recovered to pre-treatment levels by the end of one growing season without treatment. Sprout growth was influenced by the extent of carbohydrate reserves present before treatment. Biomass and heights of sprouts were significantly lower in growing-season-treated plants than those treated in the dormant season, even when data were adjusted for different lengths of recovery time. All treatments reduced the cover of the target invasive shrub. As the plants sprouted, they regained some of their initial cover and are expected to dominate without further treatment. Timing treatments to the cycle of TNC can increase the effectiveness of control methods, although repeated treatments may be necessary for several years.

This investigation involved post-colonial (∼85 years old), ponderosa pine (Pinus ponderosa var. scopulorum Engelm.) growing at ∼2,255 m in northern Arizona an area that historically experienced a wildfire event every 5-20 years. Such fires were typically limited to surface fuels and thus seldom effected stand replacement. However, since the settlement of European peoples in approximately the 1880's fire cycles have been dramatically altered by the systematic suppression of all wildland fire. This change greatly increased seedling survivorship, and has resulted in a forest with historically unprecedented stem densities. Under current conditions, with individual trees receiving insufficient nourishment, many ponderosa pine forests have demonstrated stagnated growth and increased risk of pathogenic attack or catastrophic wildfire. In response to deteriorating forest conditions and the building threat of wildfire many forest managers are exploring methods of reestablishing natural cycles to restore historical stand dynamics. Typically this effort has included timber harvesting and/or the use of prescribed fire. In this application timber harvesting typically involves removing the younger cohort of post-settlement trees. While the objectives of prescribed fire are similar to timber harvesting, fire is by its nature less precise; treatment can not be limited to a target demographic. As a result, the application of prescribed fire can lead to different stand conditions than tree removal. It is also common (especially under extreme stem densities) to have a timbering operation precede a fire treatment. The impact of these three scenarios on residual ponderosa pine tree reserves is not well understood. This project has taken part in cooperation with the USDA Forest Service and the national Fire and Fire Surrogate task group. The experiment was arranged with a 2 x 2 factorial design which resulted in four treatments. Plots were either timber harvested, burned with prescribed fire, cut than burned, or left untreated with treatment application occurring in 2002-03, three years prior to initial sampling. Trees were sampled with one of two methods. Initially a randomly selected coarse lateral root was mechanically exposed for three meters; roughly the average canopy drip line radius whereupon root tissue was extracted at intervals starting at the root collar. This disruptive method was eventually replaced by limiting sampling to the root collar. To slow metabolic activity root tissue samples were field chilled before being oven dried. Dried samples were ground through a 40# mesh and then triple-extracted with ethanol for carbohydrate quantification with high performance liquid chromatography (HPLC). Carbohydrate samples were processed at the University of Massachusetts Cranberry Experiment Station in Wareham MA. with an ion exchange column and a refractive index detector using water as a mobile phase. Starch quantifications were conducted on sub-samples by Cumberland Valley Analytical Services INC. (Maugansville, MD.) using an alpha-amylase digestion and color metric evaluation on an Astoria auto analyzer. As a result of this project it was determined that the ponderosa pine root non-structural carbohydrate components are sucrose, glucose, fructose, xylose and starch. Reserve concentrations of soluble (EtOH) carbohydrates declined significantly between May and August on plots that were not treated with prescribed fire, burning eliminated this seasonal difference. Starch and total non-structural carbohydrates were also found to be lower in August (compared to May) suggesting that during the summer (May–August), ponderosa pine must draw upon reserves. It was also found that carbohydrate concentrations increased significantly with distance from the root collar. When sampled on a monthly basis it was determined that carbohydrates, both individually and collectively, were significantly affected by the month of sampling and that overall timber harvesting reduced total soluble (EtOH) sugar concentrations. It is believed that collectively carbohydrate concentrations were a reflection of the bi-modal precipitation pattern of northern Arizona; spring snow-melt in particular, appears to have significant increased stored reserves. Key Words: Pinus ponderosa, prescribed fire, restoration, Southwest, thinning

Endurance athletes have long benefited from ingesting carbohydrates prior to, and during endurance events. Fatigue during endurance exercise has repeatedly been associated with the depletion, or reduction, of bodily carbohydrate reserves. The improved endurance capability observed after aerobic training has, however, been attributed to the increased oxidation of fat relative to carbohydrate, thereby having a 'carbohydrate sparing" effect and thus delaying the point at which reduced carbohydrate reserves will cause fatigue. This study was therefore designed to investigate the effects of medium-chain triglyceride (MCT) and carbohydrate (CHO) supplementation, on the performance and metabolic parameters of nine male marathon athletes. These results were then statistically compared to the effects of adding L-carnitine to the MCT and CHO supplement, on the same parameters. Metabolic parameters included nutritional status evaluations, serum organic acid profiles (non-esterified fatty acid and L-lactate profiles), and plasma carnitine determinations. Performance was measured in terms of peak treadmill running speed, V02 max, respiratory exchange ratios, heart rates, vco2 and vo2 data during progressive treadmill exercise tests. Nutrition and energy intakes were recorded during the study, as well as record kept of the athlete's training programmes. At the end of each supplementation period, a standard marathon was included in the experimental design, in order to practically validate controlled laboratory results. The main findings of this study included the identification of two athletes as 'fat burners'~ Non-esterified fatty acid (NEFA) profiles indicated that they predominantly relied on fatty acid oxidation during exercise, after MCT supplementation. The latter presumably because of adaptive changes in their metabolism, enabling them to benefit from MCT supplementation. In spite of the majority of athletes relying on carbohydrate metabolism during exercise, the addition of L-carnitine to the MCT and CHO supplement, induced a shift towards lipid metabolism; evident from RER and VC02 data, as well as the majority of athletes improving their performance. The observed shift was slight; the latter being ascribed to the relatively small dose of L-carnitine (compared to previous studies) included in the supplement. However, L-carnitine was incorporated into a palatable, liquid MCT and CHO supplement, and not merely administered in the form of a pharmacological dose. A major, and extremely unexpected finding, was the presumed effect that the winter, and continuous cold exposure, had on plasma carnitine levels. Plasma carnitine levels decreased significantly, without any intervention, prior to the start of the second trial period, which stretched over the middle of winter. Despite carnitine supplementation, plasma carnitine levels still decreased. This occurrence most certainly influenced results; the shift towards lipid metabolism would presumably have been more pronounced, had the 'Winter factor' not come into play.
Dissertation (MSc)--University of Pretoria, 2012.
Physiology
unrestricted

Dissertação de mestrado em Biologia Molecular, Biotecnologia e Bioempreendedorismo em Plantas
Grapevine (Vitis vinifera L.) is one of the world's most widely cultivated fruit species. The source/sink ratio is an important agronomical parameter that influences the sensory properties of the berries and plant productivity. Also, it may alter starch reserves accumulated in the amyloplast of sink tissues, like the woody canes, trunk, and roots, that are necessary to sustain rapid seasonal growth phases typical of the grapevine. Thus, in this study, we took advantage of the ability to precisely control the number of leaves to fruits in grapevine fruiting-cuttings to study the effect of source/sink ratio (2L, two leaves per cluster; 6L, six leaves per cluster, and 12L, twelve leaves per cluster) on the metabolism and accumulation of starch in canes. Cabernet Sauvignon fruiting-cuttings were selected and the work was carried out in collaboration with the Institut des Sciences de la Vigne et du Vin (ISVV) from Bordeaux - France. The total amount of starch was significantly higher in canes from 6L (42.13 ± 1.44 mg g DW-1) and 12L (43.50 ± 2.85 mg g DW-1) than in 2L (22.72 ± 3.10 mg g DW-1) fruiting-cuttings. Moreover, carbon limitation promoted a transcriptional adjustment of genes involved in starch metabolism in grapevine woody tissues. For instance, the expression of VvGPT1 and VvNTT, that code for plastidic glucose-6-phosphate/phosphate and ATP/ADP translocators, respectively, were upregulated in one-year canes from 12L plants. Contrarily, the transcript levels of the gene coding the catalytic subunit VvAGPB1 of the VvAGPase complex were higher in canes from 2L plants than in 6L and 12L, which positively correlated with the biochemical activity of this enzyme measured in tissue protein extracts. Soluble sugars were analyzed in one-year canes, and it was found that sucrose concentration increased significantly from 2L to 6L and 12L plants, and the amount of total phenolics followed the same trend. In agreement, qRT-PCR showed that the expression of VvSusy (Vitis vinifera Sucrose synthase) decreased from 2L plants to 6L and 12L, which correlated with the biochemical activity of insoluble invertase measured in tissue protein extracts. Contrarily, the expression of the sugar transporters VvSUC11 and VvSUC12, together with VvSPS1, which codes an enzyme involved in sucrose synthesis, increased from 2L plants to 6L and 12L. Overall, the results obtained in this work suggested that a mechanism regulating starch accumulation involving sucrose as a signal molecule is occurring in grapevine woody tissues in response to source/sink modulation, and that severe leaf removal may have short- and medium-term negative effects in plant productivity.
A videira (Vitis vinifera L.) é uma das espécies frutícolas mais cultivada a nível mundial. O rácio entre os tecidos produtores e de armazenamento (“source/sink”) é um parâmetro agronómico importante que influencia as características sensoriais do bago, bem como a produtividade da planta. Além disso, o rácio “source/sink” pode alterar a acumulação de amido nos amiloplastos de tecidos de armazenamento, como as varas lenhosas, troncos e raízes, que são necessários para o crescimento sazonal rápido típico da videira. Assim, no presente estudo, utilizámos o modelo de estacas enraizadas de videira que permite controlar com precisão o rácio “source/sink” (2L, duas folhas por cacho; 6L, seis folhas por cacho e 12L, doze folhas por cacho) e estudar o seu efeito no metabolismo e acumulação de amido nas varas. Foram utilizadas videiras da variedade Cabernet Sauvignon e o trabalho decorreu em colaboração como o Institut des Sciences de la Vigne et du Vin (ISVV) de Bordéus – França. Os níveis de amido medidos foram significativamente superiores em varas de plantas 6L (42,13 ± 1,44 mg/g peso seco) e 12L (43,50 ± 2,85 mg/g peso seco) do que de plantas 2L (22,72 ± 3,10 mg/g peso seco). Em paralelo, observou-se que a remoção das folhas promoveu uma reprogramação ao nível transcricional de genes envolvidos no metabolismo do amido nos tecidos lenhosos. Por exemplo, a expressão dos genes VvGPT1 e VvNTT, que codificam os trocadores plastidiais glucose-6-fosfato/fosfato e ATP/ADP, respetivamente, foi estimulada em varas de um ano de plantas 12L. Contrariamente, os níveis de transcrição do gene que codifica a subunidade catalítica VvAGPB1 do complexo VvAGPase foram mais elevados em varas de plantas 2L do que em varas de plantas 6L e 12L, tendo-se verificado uma correlação com a atividade bioquímica da enzima medida em extratos proteicos dos tecidos. Os açúcares solúveis nas varas de um ano foram analisados e os resultados demostraram que a concentração de sacarose aumentou significativamente em varas de plantas 2L para 6L e 12L, e que a quantidade de compostos fenólicos totais seguiu a mesma tendência. Em paralelo, estudos de expressão por qRT-PCR revelaram que os níveis de transcritos do gene VvSusy (Vitis vinifera Sucrose synthase) diminuíram em varas de plantas 2L para 6L e 12L, tendo-se identificado uma correlação com a atividade bioquímica da invertase insolúvel medida em extratos proteicos. Contrariamente, a expressão dos transportadores de açúcar VvSUC11 e VvSUC12, bem como a expressão do gene VvSPS1, que codifica uma enzima envolvida na síntese de sacarose, aumentou em varas de plantas 2L para 6L e 12L. No seu conjunto, os resultados sugeriram que a sinalização pelos níveis de sacarose está envolvida na regulação da acumulação do amido nos tecidos lenhosos da videira em resposta a modificações nas relações “source/sink” e que a desfolha severa pode ter efeitos negativos a curto e a médio prazo na produtividade da planta e na qualidade do fruto.

Thesis (M.S.)--University of Wisconsin--Madison, 1985.
Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 145-155).

Two experiments were conducted to examine the role of carbohydrate reserves in spring root growth potential (RGP)of Engelmann spruce (Picea engelmannii Parry) seedlings. In the first experiment, the effects of pre-storage carbon dioxide enrichment (CE) on total non-structural carbohydrates (TNC) and post-storage root growth were studied. Seedlings were grown from seed for 202 days in growth chambers with ambient (340 μL•L-1) and CO2 enriched(1000 μL•L-1) air. Reciprocal transfers between treatments took place at 60 and 120 days. Photoperiod was reduced at100 days to induce bud set. After 180 days seedlings were hardened-off for storage at -5°C. At 268 and 327 days, seedlings were planted in a growth chamber in three water baths. New roots >5 mm long were counted after 28 days growth. Seedlings were also assessed for bud break every two days. At each planting time, and at 80, 120, 140, and 202days, seedlings were randomly selected from each of the CO2 treatments and harvested for analysis of starch and soluble sugar content. Growth data were also collected. In the second experiment, the relative contributions of reserve carbon and current photosynthate to new root growth were studied. Seedlings were raised using standard nursery procedures up to bud set (end of September, 1990). Seedlings were then moved into a growth chamber and placed in four Plexiglas boxes for stable carbon isotope labelling. Two boxes received ambient CO2 with normal isotopic composition [More abstracts follows]

Cranberry (Vaccinium macrocarpon Ait.) is a woody perennial crop that can remain productive for decades. Competition for resources between cranberries and weeds can depress cranberry farm yields, resulting in large annual crop losses. Renewed interest in reducing chemical inputs into cranberry systems has provided the motivation to evaluate methods, such as flame cultivation (FC), as potential nonchemical options for weed control. Also known as thermal weeding, FC exposes plants to brief periods of high temperature that causes the water in the plant tissue to expand rapidly, rupturing plant cells and leading to necrosis. Various FC methods have been used successfully in annual crops as both a preemergence and postemergence weed control, but few scientific reports have been published on the use of FC on perennial weeds in a woody perennial crop system. Dewberry (Rubus spp.), sawbrier (Smilax glauca), and common rush (Juncus effusus ) are cranberry weeds that are difficult to control, spread quickly and can cause significant crop loss. Flame cultivation may be an effective non-chemical means for controlling these weeds in cranberry systems. FC would ideally be used as a spot treatment for weeds growing in the cranberry canopy, as well as on larger non-production areas where cranberry vines are not as abundant, such as bog edges, ditches, and dikes. Using FC to treat weeds within the cranberry canopy will likely cause localized damage to cranberry plants immediately surrounding the weeds, thus cranberry response to FC is also of interest. The following experiments were designed to examine the response of weeds and cranberry plants to FC. Perennial plants rely on reserves of nonstructural carbohydrates (NSC) for growth and survival, thus the efficacy of FC treatments to weeds will likely be impacted by the timing and frequency of treatments as they relate to the specific carbohydrate cycles of targeted weeds, such as dewberry. An additional experiment studied the seasonal fluctuations of NSC in dewberry roots. Cranberry growers were also surveyed on their past experiences with FC, as well as their willingness to adopt FC if proven an effective method for controlling weeds.

Disturbances, such as herbivory and fire are commonplace in savanna ecosystems. The effects of herbivory and fire on growth and defences of adult trees is a much studied filed in plant ecology. However, there are comparatively few studies that have investigated the effects of herbivory and fire on seedling growth, defences and establishment. African Acacia trees are common and widespread, and are suggested to be keystone species in savanna ecosystems. They have been shown to significantly positively increase soil characteristics, such as soil moisture and infiltration, while also increasing spatial heterogeneity of savannas. These trees are distinguishable by their array of physical and chemical defences. Physical defences are either in the form of spines (physiologically costly to produce, thus considered inducible) or prickles (physiologically cheap to produce, thus considered constitutive), while condensed tannins are the most common form of chemical defences. Adult Acacia trees have been shown on several occasions to be highly resilient to disturbance events, primarily due to their large size. However, the effects of herbivory and fire on Acacia seedlings have been little studied despite their apparent importance for our understanding of African savanna ecosystem functioning. In two separate experiments, this thesis aimed to investigate the individual and combined effects of simulated herbivory and fire on the regrowth, defences, and total non-structural carbohydrates (TNC) of the seedlings of several Acacia species, while also testing the Resource Availability Hypothesis (RAH) (14 Acacia species) and the Expanded Growth-Differentiation Balance Hypothesis (GDBH) (three Acacia species). The RAH (Coley, Bryant & Chapin 1985) and the GDBH (Loomis 1932) both assume that arid-adapted (resource-poor) species are slow growing, with low tissue turnover rates. Contrastingly, humid-adapted (resource-rich) species have fast growth rates and thus a high tissue turnover rate. Therefore, arid-adapted species are predicted to invest more carbohydrate reserves in defence after a disturbance event, in order to defend new photosynthetic material. Conversely, humid-adapted (resource-rich) species are predicted to invest carbohydrate reserves into increased growth after a disturbance event, in order to compensate for tissue loss. The first greenhouse experiment found that, in accordance with the RAH, humid-adapted species displayed elevated growth rates compared to arid-adapted species. Overall, defences significantly increased after herbivory, but significantly decreased after fire. Herbivory was also shown to significantly reduce TNC stores in roots more than fire. We found that arid-adapted species did indeed invest more carbohydrate stores (TNC) into defence, and displaying an increase in spine and prickle abundance, spine and prickle length, and condensed tannin concentration. Humid-adapted species displayed an increase in growth rather than in defence, with the majority of species only increasing one defensive trait. Humid-adapted species also displayed significant trade-offs (negative correlations) between new stem growth and defence traits, while arid-adapted species overall did not display any significant trade-offs between stem growth and increased defences. The majority of arid-adapted species also displayed an allometric effect for spine abundance and length, with an increase in one trait led to an increase in the other. Prickles were found to be inducible, despite the assumption that due to low physiological cost, they are no inducible. Herbivory and fire were shown to not be substitutable in their effects on Acacia seedlings in a controlled experimental setting. The second greenhouse experiment tested the Expanded Growth-Differentiation Balance Hypothesis (GDBH) in the seedlings of A. erioloba, A. karroo, and A. nilotica using five levels of nutrient availability. Overall, spine abundance and spine length displayed a unimodal trend in all three species, with spine abundance and spine length being greatest at a nutrient availability of 800 mg/ ℓ. Spine abundance, spine length and condensed tannins increased significantly after herbivory, but were shown to significantly decrease after fire. We found that with an increase in nutrient availability, the growth of stems and roots, along with the production of TNC in roots and stems of all species significantly increased. Our data provide mixed support for the assumptions and predictions of the expanded GDBH. The regrowth of stems and physical defences were consistent with the GDBH. Chemical defences (i.e. condensed tannins) were however, inconsistent with the predictions of the GDBH. We have shown that Acacia seedlings are highly resilient to disturbance events, while the growth responses of Acacia seedlings are underpinned by TNC stores in roots. Simulated herbivory and fire are often substituted for one another in controlled experiments. However, we have shown that the effects of herbivory and fire have significantly different effects on regrowth patterns of Acacia seedlings.
Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2011.

The Wandering albatross Diomedea exulans, due to its behavior and biology, is often used as a top predator model. This species spends a great time in the ocean searching for food and only comes ashore during the breeding season. This study aimed to determine and compare the fatty acid and carbohydrates profile of male and female traveling albatrosses, between May and October 2009, in order to verify potential differences in the diet and infer about the body condition of individuals of both sexes and the months of sampling, during chick rearing. We analyzed 34 breeding adults (18 females and 16 males). The samples were collected on Bird Island, South Georgia, for further analysis of the biochemical profile in plasma and blood samples from each individual. In the analysis of fatty acids, it was observed that there were differences between tissues (plasma and blood) (F = 68.31; p < 0.01) but not between sexes and months. A greater abundance of FA in the plasma (98%) was observed in relation to blood samples. Saturated (SFA) and monounsaturated (MUFA) fatty acids were the most abundant FA. Polyunsaturated fatty acids (PUFA) were only observed in blood samples from individuals of both sexes. Although differences were observed over the months in both blood and plasma, these were not significant. Males showed a greater amount of FA (63%) in July and females in May (68%), in plasma samples, whereas in blood samples this pattern was observed in October for males (85%) and in September for females (67%). In the analysis of sugars, significant differences were also observed between tissues (F = 56.02; p < 0.01) but not between sexes and months. There was a greater abundance of carbohydrates in plasma samples than in blood samples, with Glucose showing greater abundance. In plasma, males showed a peak in October (71%) and females in July (55%), as well as in blood. These results show that both males and females contribute to the care of the young, not showing differences between sexes, and that both have to spend their energy reserves during the breeding season. However, males seem to be able to recover more quickly.
O albatroz-viageiro Diomedea exulans, devido ao seu comportamento e biologia, é muitas vezes utilizado como modelo de predador de topo. Esta espécie passa grande parte do tempo no oceano à procura de alimento e apenas vem a terra na época de reprodução. Neste estudo pretendeu-se determinar, e comparar, o perfil em ácidos gordos e açúcares de machos e fêmeas de albatrozes viageiros, entre Maio e Outubro de 2009, de modo a verificar potenciais diferenças na dieta e inferir sobre a condição corporal dos indivíduos de ambos os sexos e os meses de amostragem durante o período de reprodução e cuidados com as crias. Analisámos 34 adultos reprodutores (18 fêmeas e 16 machos). As amostras foram recolhidas na ilha de Bird, na Geórgia do Sul, para posterior análise do perfil bioquímico em amostras de plasma e sangue de cada individuo. Na análise dos ácidos gordos observou-se que existiam diferenças entre tecidos (plasma e sangue) (F=68.31; p<0.01) mas não entre sexos e os meses de amostragem. Observou-se uma maior abundância de ácidos gordos no plasma (98%) em relação às amostras de sangue. Os ácidos gordos saturados (SFA) e monoinsaturados (MUFA) foram os mais abundantes. Ácidos gordos poli insaturados (PUFA) foram apenas observados em amostras de sangue de indivíduos de ambos os sexos. Apesar de se terem observado diferenças ao longo dos meses tanto no sangue como no plasma, estas não foram significativas. Os machos apresentaram uma maior quantidade de ácidos gordos (63%) em julho e as fêmeas em Maio (68%), nas amostras de plasma, enquanto que nas amostras de sangue este padrão foi observado em Outubro para os machos (85%) e em Setembro para as fêmeas (67%). Na análise de açúcares também se observaram diferenças significativas entre tecidos (F=56.02; p<0.01) mas não entre sexos e os meses de amostragem. Registou-se uma maior abundância de açúcares em amostras de plasma do que em amostras de sangue, com a Glucose a apresentar uma maior abundância. No plasma, os machos apresentaram um pico em Outubro (71%) e as fêmeas em Julho (55%), assim como no sangue. Estes resultados evidenciam que tanto os machos como as fêmeas contribuem nos cuidados da cria, não se observando diferenças entre sexos, e que ambos têm de gastar reservas energéticas nesta época de reprodução. No entanto, os machos parecem conseguir recuperar mais rapidamente.
Mestrado em Biologia Marinha Aplicada