Estudos têm mostrado a incidência de mastite bovina associada à alga Prototheca zopfii. O objetivo deste trabalho foi estudar a interação da P. zopfii com neutrófilos recuperados de leite bovino e avaliar o efeito do sistema ácido indol-3-acético/peroxidase de raiz forte (AIA/HRP) sobre a viabilidade deste microrganismo em experimentos in vitro. A P. zopfii foi recuperada de vacas com mastite clínica e, no laboratório, foram realizadas a caracterização molecular, morfológica e crescimento exponencial do microrganismo. Em seguida, neutrófilos recuperados de leite bovino foram incubados na ausência e na presença de P. zopfii opsonizada e foram avaliadas a produção de peróxido de hidrogênio, enzimas antioxidantes dos neutrófilos e microrganismo, e a capacidade fagocitária. Em outro estudo, a P. zopfii foi incubada com o sistema AIA/HRP e foram avaliadas a viabilidade por unidades formadoras de colônias (UFC), atividade de enzimas antioxidantes, integridade de membrana por exclusão com azul de Trypan e integridade do DNA. Os resultados foram analisados pela análise de variância com significância de 5% usando o teste Tukey. Foram observados diversos tamanhos celulares da P. zopfii, presença de autofluorescência, crescimento exponencial ao longo do tempo de incubação em que não foi possível determinar o início da fase de morte. Ainda, foram encontrados os genótipos 1, 2 e 3 nos isolados em estudo. A produção de peróxido de hidrogênio pelos neutrófilos na presença da alga foi estimulada 5 vezes em relação ao controle, estimulou a atividade das enzimas catalase (CAT) em 21% e glutationa redutase (GR) em 27% e não houve diferença significativa quanto à atividade de CAT, GR e superóxido dismutase (SOD) produzido pela P. zopfii. Também foi verificado que a P. zopfii não foi englobada pelo neutrófilo. O sistema AIA/HRP inibiu o crescimento do microrganismo em 45, 82 e 88% nos tempos de 4, 6 e 9 horas de incubação; a atividade da SOD, CAT, Glutationa Peroxidase (GPx) e GR aumentou respectivamente em 90, 120, 150% e 3,4 vezes; houve redução da viabilidade da P. zopfii em 10, 15, 20, 25 e 32% após os tempos de 4, 6, 8, 10 e 12 horas de incubação; e não afetou a integridade do DNA após 6 horas de incubação. Conclui-se que a P. zopfii é altamente resistente frente aos neutrófilos e demonstrou ser susceptível quanto ao efeito microbicida do sistema AIA/HRP. / Studies have shown the incidence of bovine mastitis associated with the algae Prototheca zopfii. The objective of this work was to study the interaction of P. zopfii with neutrophils recovered from bovine milk and to evaluate the effect of system indole-3-acetic acid/horseradish peroxidase (IAA/HRP) on the viability of this microorganism in vitro experiment. P. zopfii was recovered from cows with clinical mastitis and both the molecular and morphological characterization were performed besides the evaluation of exponential growth of the microorganism in the laboratory. Next, neutrophils recovered from bovine milk were incubated in the absence and presence of opsonized P. zopfii and were evaluated the production of hydrogen peroxide, antioxidant enzymes on neutrophils and microorganism, and phagocytic capacity. In another study, P. zopfii was incubated with the system IAA/HRP and the viability assessed by colony forming units (CFU), antioxidant enzymes activity, membrane integrity by exclusion with Trypan blue and DNA integrity. The results were analyzed by analysis of variance with a 5% significance using the Tukey test. Results from P. zopfii characterization showed various cellular sizes, presence of autofluorescence, exponential microorganism growth throughout the incubation time and was not possible to determine the beginning of the death. Moreover it was found genotypes 1, 2 and 3 in the isolates in study. The production of hydrogen peroxide by neutrophils in the presence of algae was stimulated 5 times compared to the control, increase the activity of catalase (CAT) in 21% and glutathione reductase (GR) in 27% was seen in neutrophils; and there was no significant difference in CAT, GR and superoxide dismutase (SOD) activity produced by P. zopfii. P. zopfii was not engulfment by neutrophils. The system IAA/HRP inhibited the growth of the microorganism in 45, 82 and 88% in the times of 4, 6 and 9 hours of incubation, the activity of SOD, CAT, glutathione peroxidase (GPx) and GR increased respectively by 90, 120, 150%, and 3.4 times, decreased the viability of P. zopfii 10, 15, 20, 25 and 32% after the times of 4, 6, 8, 10 and 12 hours of incubation, and did not affect the integrity of DNA after 6 hours of incubation. As a conclusion, P. zopfii is highly resistant to the neutrophils and demonstrated to be susceptible to the effect microbicidal of system IAA/HRP.

Estudos têm mostrado a incidência de mastite bovina associada à alga Prototheca zopfii. O objetivo deste trabalho foi estudar a interação da P. zopfii com neutrófilos recuperados de leite bovino e avaliar o efeito do sistema ácido indol-3-acético/peroxidase de raiz forte (AIA/HRP) sobre a viabilidade deste microrganismo em experimentos in vitro. A P. zopfii foi recuperada de vacas com mastite clínica e, no laboratório, foram realizadas a caracterização molecular, morfológica e crescimento exponencial do microrganismo. Em seguida, neutrófilos recuperados de leite bovino foram incubados na ausência e na presença de P. zopfii opsonizada e foram avaliadas a produção de peróxido de hidrogênio, enzimas antioxidantes dos neutrófilos e microrganismo, e a capacidade fagocitária. Em outro estudo, a P. zopfii foi incubada com o sistema AIA/HRP e foram avaliadas a viabilidade por unidades formadoras de colônias (UFC), atividade de enzimas antioxidantes, integridade de membrana por exclusão com azul de Trypan e integridade do DNA. Os resultados foram analisados pela análise de variância com significância de 5% usando o teste Tukey. Foram observados diversos tamanhos celulares da P. zopfii, presença de autofluorescência, crescimento exponencial ao longo do tempo de incubação em que não foi possível determinar o início da fase de morte. Ainda, foram encontrados os genótipos 1, 2 e 3 nos isolados em estudo. A produção de peróxido de hidrogênio pelos neutrófilos na presença da alga foi estimulada 5 vezes em relação ao controle, estimulou a atividade das enzimas catalase (CAT) em 21% e glutationa redutase (GR) em 27% e não houve diferença significativa quanto à atividade de CAT, GR e superóxido dismutase (SOD) produzido pela P. zopfii. Também foi verificado que a P. zopfii não foi englobada pelo neutrófilo. O sistema AIA/HRP inibiu o crescimento do microrganismo em 45, 82 e 88% nos tempos de 4, 6 e 9 horas de incubação; a atividade da SOD, CAT, Glutationa Peroxidase (GPx) e GR aumentou respectivamente em 90, 120, 150% e 3,4 vezes; houve redução da viabilidade da P. zopfii em 10, 15, 20, 25 e 32% após os tempos de 4, 6, 8, 10 e 12 horas de incubação; e não afetou a integridade do DNA após 6 horas de incubação. Conclui-se que a P. zopfii é altamente resistente frente aos neutrófilos e demonstrou ser susceptível quanto ao efeito microbicida do sistema AIA/HRP. / Studies have shown the incidence of bovine mastitis associated with the algae Prototheca zopfii. The objective of this work was to study the interaction of P. zopfii with neutrophils recovered from bovine milk and to evaluate the effect of system indole-3-acetic acid/horseradish peroxidase (IAA/HRP) on the viability of this microorganism in vitro experiment. P. zopfii was recovered from cows with clinical mastitis and both the molecular and morphological characterization were performed besides the evaluation of exponential growth of the microorganism in the laboratory. Next, neutrophils recovered from bovine milk were incubated in the absence and presence of opsonized P. zopfii and were evaluated the production of hydrogen peroxide, antioxidant enzymes on neutrophils and microorganism, and phagocytic capacity. In another study, P. zopfii was incubated with the system IAA/HRP and the viability assessed by colony forming units (CFU), antioxidant enzymes activity, membrane integrity by exclusion with Trypan blue and DNA integrity. The results were analyzed by analysis of variance with a 5% significance using the Tukey test. Results from P. zopfii characterization showed various cellular sizes, presence of autofluorescence, exponential microorganism growth throughout the incubation time and was not possible to determine the beginning of the death. Moreover it was found genotypes 1, 2 and 3 in the isolates in study. The production of hydrogen peroxide by neutrophils in the presence of algae was stimulated 5 times compared to the control, increase the activity of catalase (CAT) in 21% and glutathione reductase (GR) in 27% was seen in neutrophils; and there was no significant difference in CAT, GR and superoxide dismutase (SOD) activity produced by P. zopfii. P. zopfii was not engulfment by neutrophils. The system IAA/HRP inhibited the growth of the microorganism in 45, 82 and 88% in the times of 4, 6 and 9 hours of incubation, the activity of SOD, CAT, glutathione peroxidase (GPx) and GR increased respectively by 90, 120, 150%, and 3.4 times, decreased the viability of P. zopfii 10, 15, 20, 25 and 32% after the times of 4, 6, 8, 10 and 12 hours of incubation, and did not affect the integrity of DNA after 6 hours of incubation. As a conclusion, P. zopfii is highly resistant to the neutrophils and demonstrated to be susceptible to the effect microbicidal of system IAA/HRP.

Dentre os vários processos que concorrem para o amadurecimento da banana, a degradação do amido e sua conversão em açúcares solúveis, principalmente sacarose, são dois dos processos mais relevantes para a obtenção o sabor doce característico do fruto maduro. Embora venha sendo estudado há anos, ainda não foram esclarecidos quais os mecanismos regulatórios e os possíveis sinais hormonais envolvidos no controle da degradação do amido e na síntese da sacarose. O presente estudo objetivou avaliar o efeito do ácido indol-3-acético (AIA), um hormônio da classe das auxinas com reconhecido efeito retardador do amadurecimento, sobre o metabolismo amido-sacarose e algumas enzimas correlacionadas, em bananas. Observou-se um forte efeito retardador do hormônio sobre a degradação do amido no amido durante o amadurecimento de fatias de bananas infiltradas com uma solução contendo AIA em manitol, em comparação com fatias controle infiltradas apenas com manitol. As atividades de alfa e ß-amilase e alfa-1,4-glicosidase neutra foram afetadas pelo AIA, apresentando atraso no desenvolvimento de suas atividades durante o amadurecimento, quando comparadas às fatias controle. A atividade da fosforilase de amido aparentemente não foi afetada. A transcrição do mRNA da ß-amilase foi atrasada pelo AIA e pôde ser correlacionada ao atraso na degradação do amido Os resultados sugerem que o atraso na mobilização do amido provocado pelo AIA deve decorrer de seus efeitos sobre as enzimas amilolíticas. O trabalho também sugere a relevância da ß-amilase para o processo e que esta enzima, ao menos em parte, é regulada por transcrição. No sentido da síntese de sacarose, as atividades de SuSy e SPS não mostraram alterações significativas. A transcrição do mRNA da SuSy e da SPS não foram afetadas. O atraso no acúmulo da sacarose, observado nas fatias infiltradas com o hormônio, pode ser conseqüência da limitação de substrato para a síntese deste açúcar devido ao atraso na degradação do amido. Medidas de etileno revelaram que a produção deste hormônio não foi afetada pelo AIA, sugerindo que a degradação do amido, pelo menos em parte possa ser um evento etileno- independente. Medidas da forma livre do AIA endógeno nas fatias controle e em bananas inteiras, mostraram que os níveis desta auxina decrescem durante o amadurecimento, atingindo os menores valores durante a mobilização do amido. Nas fatias tratadas, as medidas da forma livre do AIA e de seus conjugados mostraram a existência de um eficiente sistema capaz de mobilizar o excesso do hormônio no tecido e acomodando os níveis da forma livre aos mesmos encontrados nas fatias controle e nas bananas inteiras. Esta observação pode ser temporalmente correlacionada ao atraso na degradação do amido. O presente estudo mostrou não apenas a capacidade do AIA em afetar o metabolismo amido-sacarose em bananas mas também sugere que este hormônio pode ser parte dos sinais que regulam o madurecimento em bananas. / During banana ripening, starch degradation and sucrose formation are important processes responsible for the sweetening of ripe fruit. Although has been studied for several years, the regulation and hormonal signals that control these metabolic processes still remains not clear. The objective of this work has been evaluate the effect of indole-3-acetic acid (IAA), an auxin with inhibitory effect on ripening, on starch-to-sucrose metabolism and some correlated enzymes. The results showed a delay on starch degradation in slices infiltrated with IAA plus mannitol comparing to slices infiltrated only with mannitol. The activities of alfa- and ß-amylase and alfa-1,4-glucosidase was delayed. Starch phosphorylase was not affected. These results suggest that IAA can delay starch degradation inhibiting, at least partially, the amylolitic activity. Synthesis of ß-amylase mRNA was strong delayed on IAA-treated slices comparing to control slices, indicating that this enzyme could be, at least partially, regulated at the transciptional level. In sucrose synthesis direction, sucrose synthase (SuSy) and sucrose-phosphate synthase (SPS) activities and mRNA transcription were not affected. This suggests that delay on sucrose formation could be a consequence of lack of substrate, since starch degradation was inhibited. Ethylene measurements didn\'t reveal any significant differences between control and IAA-treated slices suggesting that starch degradation on banana ripening could be a ethylene-independent event. Free endogenous IAA measurements on control slices and whole banana fruit showed that this IAA fraction decrease continuously in the pulp of banana during ripening, reaching the lowest levels at the same time that starch degradation begun. On IAA-treated slices, the free plus conjugate IAA showed the existence of an efficient system that mobilized the hormone excess and brought the free IAA to the same levels of control and whole fruit. This could be timely correlated with the delay on starch degradation. This work shows not only that IAA can delay the starch degradation but also suggest that IAA could be part of regulatory signals involved on banana ripening.

Um gene que codifica uma piruvato/indolpiruvato descarboxilase (PDC/IPDC) está presente no tripanossomatídeo de plantas Phytomonas serpens. A PDC atua na fermentação alcoólica, enquanto que a IPDC atua na biossíntese do fitormônio ácido indol-3-acético (AIA). Análises filogenéticas indicam que a PDC/IPDC de P. serpens é monofilética com IPDCs de gama-proteobactérias, sugerindo um evento de transferência horizontal gênica. A análise de meios de cultura de P. serpens confirma a produção de etanol e AIA. A funcionalidade do fitormônio foi confirmada em ensaios de alongamento de hipocótilos de tomateiros. Tomates inoculados com P. serpens mostraram aumento no teor de AIA-amida e -éster conjugados. A atividade PDC foi mostrada em extratos de P. serpens. Concluímos que a PDC/IPDC seria uma 2-cetoácido descaboxilase com atividade catalítica variável para diferentes substratos. A atividade PDC parece ser predominante em P. serpens, representando um mecanismo para oxidar parte do NADH formado na glicólise, principal responsável pela produção de ATP neste organismo. / A gene codifying a pyruvate/indolepyruvate decarboxylase (PDC/IPDC) is present in the plant trypanosomatid Phytomonas serpens. PDC acts in the alcoholic fermentation, whyle IPDC acts in the biosynthesis of the phytohormone indole-3-acetic acid (IAA). Phylogenetic analysis indicate that P. serpens PDC/IPDC is monophyletic with gamma-proteobacteria IPDCs, suggesting a horizontal gene transfer event. Analysis of P. serpens culture media confirms production of ethanol and IAA. The functionality of the phytohormone was confirmed by tomato hypocotyl elongation tests. Tomatoes inoculated with P. serpens showed an increase in the concentration of IAA amide and ester conjugated. PDC activity was shown in P. serpens extracts. We conclude that the PDC/IPDC would be a 2-keto acid decaboxylase with variable catalytic activity for different substrates. The PDC activity appears to be prevalent in P. serpens representing a mechanism to oxidize part of NADH formed in glycolysis, responsible for ATP production in this organism.

Cotton plant growth and development, as well as monitoring nutrient use efficiency were evaluated using hydroponic approach. Two set of experiments were conducted to determine the influence of phosphorus (P), potassium (K) and PK and exogenous application of Indole-3-acetic acid (IAA), gibberellic acid (GA3), zeatin (Z) and their combinations on growth and development of cotton plants (Gossypium hirsutum) grown hydroponically. In the nutrient solution experiment, cotton vegetative growth was positively influenced by low P (half strength Hoagland standard solution), low K (one-sixth strength Hoagland standard solution) and high PK treatments (Hoagland standard solution). Phytohormone experiment negatively supported vegetative growth except root length at 43 days after transplanting (DAT). The nutrients levels applied significantly favoured NPK uptake by cotton plants while exogenous phytohormones application did not affect NPK uptake by cotton plants, except N uptake by stem. Low P and low K treatments estimated to have high nutrient use efficiency (NUE). For chlorophyll formation, low K and high PK significantly increased formation of chlorophyll a, b and total ab while the application of GA3, IAA, Z and IAA x GA3 x 2Z treatments significantly increased chlorophyll a, b and total ab at 80 DAT only. Low K and low P treatments stimulated endogenous phytohormone contents in the cotton plants. In the phytohormone experiment, cotton plants treated to IAA x GA3 x Z increased endogenous phytohormone contents in the cotton plants. Low P, low K, high PK treatments and phytohormones treatments significantly increased root area, root volume and root activity. Low P, low K and high PK treatments applied significantly influenced residual level of P and K in the hydroponics while phytohormone treatments did not affect residual level of P and K except at 43 DAT. Evapotranspiration rate was high at early and reproductive stages of plant growth. This report shows the response of mineral nutrients and phytohormones to support growth and development of cotton plants grown hydroponically. / Description as in abstract

Magister Scientiae - MSc (Biotechnology) / The yearly increase of global population will result in a greater demand for crop production, but with the climates changes and a lack of available agricultural land it will become increasingly more difficult to provide sufficient crops to feed everyone adequately. Application of the PGPE has proven over the past researches to be able enhance growth of plants via various growth promoting mechanisms. To identify suitable growth promoting bacteria candidate, E. plantagineum plant was used to isolate endophytes from the root after surface sterilization. The isolates bacteria were used to inoculate Brassica napus L seeds. The effects of isolate's ability to promote growth were evaluated based on the certain growth parameters after 42 days in the green house. Isolate CP5 produced highest results in all growth parameter. Isolates CP5 was selected as potential candidate as significant improvement was shown by this isolate. This isolate was tested for the ability to produce ACC deaminase, solubilize phosphate, synthesize IAA and siderophore production. Furthermore isolate CP5 growth promotion abilities was tested on Brassica napus L under antimony stress. / 2021-08-31

Um gene que codifica uma piruvato/indolpiruvato descarboxilase (PDC/IPDC) está presente no tripanossomatídeo de plantas Phytomonas serpens. A PDC atua na fermentação alcoólica, enquanto que a IPDC atua na biossíntese do fitormônio ácido indol-3-acético (AIA). Análises filogenéticas indicam que a PDC/IPDC de P. serpens é monofilética com IPDCs de gama-proteobactérias, sugerindo um evento de transferência horizontal gênica. A análise de meios de cultura de P. serpens confirma a produção de etanol e AIA. A funcionalidade do fitormônio foi confirmada em ensaios de alongamento de hipocótilos de tomateiros. Tomates inoculados com P. serpens mostraram aumento no teor de AIA-amida e -éster conjugados. A atividade PDC foi mostrada em extratos de P. serpens. Concluímos que a PDC/IPDC seria uma 2-cetoácido descaboxilase com atividade catalítica variável para diferentes substratos. A atividade PDC parece ser predominante em P. serpens, representando um mecanismo para oxidar parte do NADH formado na glicólise, principal responsável pela produção de ATP neste organismo. / A gene codifying a pyruvate/indolepyruvate decarboxylase (PDC/IPDC) is present in the plant trypanosomatid Phytomonas serpens. PDC acts in the alcoholic fermentation, whyle IPDC acts in the biosynthesis of the phytohormone indole-3-acetic acid (IAA). Phylogenetic analysis indicate that P. serpens PDC/IPDC is monophyletic with gamma-proteobacteria IPDCs, suggesting a horizontal gene transfer event. Analysis of P. serpens culture media confirms production of ethanol and IAA. The functionality of the phytohormone was confirmed by tomato hypocotyl elongation tests. Tomatoes inoculated with P. serpens showed an increase in the concentration of IAA amide and ester conjugated. PDC activity was shown in P. serpens extracts. We conclude that the PDC/IPDC would be a 2-keto acid decaboxylase with variable catalytic activity for different substrates. The PDC activity appears to be prevalent in P. serpens representing a mechanism to oxidize part of NADH formed in glycolysis, responsible for ATP production in this organism.

Dentre os vários processos que concorrem para o amadurecimento da banana, a degradação do amido e sua conversão em açúcares solúveis, principalmente sacarose, são dois dos processos mais relevantes para a obtenção o sabor doce característico do fruto maduro. Embora venha sendo estudado há anos, ainda não foram esclarecidos quais os mecanismos regulatórios e os possíveis sinais hormonais envolvidos no controle da degradação do amido e na síntese da sacarose. O presente estudo objetivou avaliar o efeito do ácido indol-3-acético (AIA), um hormônio da classe das auxinas com reconhecido efeito retardador do amadurecimento, sobre o metabolismo amido-sacarose e algumas enzimas correlacionadas, em bananas. Observou-se um forte efeito retardador do hormônio sobre a degradação do amido no amido durante o amadurecimento de fatias de bananas infiltradas com uma solução contendo AIA em manitol, em comparação com fatias controle infiltradas apenas com manitol. As atividades de alfa e ß-amilase e alfa-1,4-glicosidase neutra foram afetadas pelo AIA, apresentando atraso no desenvolvimento de suas atividades durante o amadurecimento, quando comparadas às fatias controle. A atividade da fosforilase de amido aparentemente não foi afetada. A transcrição do mRNA da ß-amilase foi atrasada pelo AIA e pôde ser correlacionada ao atraso na degradação do amido Os resultados sugerem que o atraso na mobilização do amido provocado pelo AIA deve decorrer de seus efeitos sobre as enzimas amilolíticas. O trabalho também sugere a relevância da ß-amilase para o processo e que esta enzima, ao menos em parte, é regulada por transcrição. No sentido da síntese de sacarose, as atividades de SuSy e SPS não mostraram alterações significativas. A transcrição do mRNA da SuSy e da SPS não foram afetadas. O atraso no acúmulo da sacarose, observado nas fatias infiltradas com o hormônio, pode ser conseqüência da limitação de substrato para a síntese deste açúcar devido ao atraso na degradação do amido. Medidas de etileno revelaram que a produção deste hormônio não foi afetada pelo AIA, sugerindo que a degradação do amido, pelo menos em parte possa ser um evento etileno- independente. Medidas da forma livre do AIA endógeno nas fatias controle e em bananas inteiras, mostraram que os níveis desta auxina decrescem durante o amadurecimento, atingindo os menores valores durante a mobilização do amido. Nas fatias tratadas, as medidas da forma livre do AIA e de seus conjugados mostraram a existência de um eficiente sistema capaz de mobilizar o excesso do hormônio no tecido e acomodando os níveis da forma livre aos mesmos encontrados nas fatias controle e nas bananas inteiras. Esta observação pode ser temporalmente correlacionada ao atraso na degradação do amido. O presente estudo mostrou não apenas a capacidade do AIA em afetar o metabolismo amido-sacarose em bananas mas também sugere que este hormônio pode ser parte dos sinais que regulam o madurecimento em bananas. / During banana ripening, starch degradation and sucrose formation are important processes responsible for the sweetening of ripe fruit. Although has been studied for several years, the regulation and hormonal signals that control these metabolic processes still remains not clear. The objective of this work has been evaluate the effect of indole-3-acetic acid (IAA), an auxin with inhibitory effect on ripening, on starch-to-sucrose metabolism and some correlated enzymes. The results showed a delay on starch degradation in slices infiltrated with IAA plus mannitol comparing to slices infiltrated only with mannitol. The activities of alfa- and ß-amylase and alfa-1,4-glucosidase was delayed. Starch phosphorylase was not affected. These results suggest that IAA can delay starch degradation inhibiting, at least partially, the amylolitic activity. Synthesis of ß-amylase mRNA was strong delayed on IAA-treated slices comparing to control slices, indicating that this enzyme could be, at least partially, regulated at the transciptional level. In sucrose synthesis direction, sucrose synthase (SuSy) and sucrose-phosphate synthase (SPS) activities and mRNA transcription were not affected. This suggests that delay on sucrose formation could be a consequence of lack of substrate, since starch degradation was inhibited. Ethylene measurements didn\'t reveal any significant differences between control and IAA-treated slices suggesting that starch degradation on banana ripening could be a ethylene-independent event. Free endogenous IAA measurements on control slices and whole banana fruit showed that this IAA fraction decrease continuously in the pulp of banana during ripening, reaching the lowest levels at the same time that starch degradation begun. On IAA-treated slices, the free plus conjugate IAA showed the existence of an efficient system that mobilized the hormone excess and brought the free IAA to the same levels of control and whole fruit. This could be timely correlated with the delay on starch degradation. This work shows not only that IAA can delay the starch degradation but also suggest that IAA could be part of regulatory signals involved on banana ripening.

Diazotrophic microbes reside in soybean nodules; however, other non-nitrogen fixing bacteria are a part of the interior nodule microbiome. Results from a previous greenhouse study show that a novel species of Pseudomonas associates with soybean nodules as a plant-growth promoting rhizobacteria (PGPR). This study observes the soybean growth promoting potential of Pseudomonas spp. in a field setting. Additionally, this study observed differences in soybean growth promotion based on amending the plant with isolated strains or a mixed culture of the species' strains. Two cultivars of soybean (Asgrow AG46X6 and Pioneer P48A60X) were either amended with isolated strains of the novel Pseudomonas spp. (referred to as PAMW1 and BUMW2 in this study), a mix of the two strains, or an uninoculated control. The study recorded measurements to observe growth, yield, and nitrogen fixation differences. The study uses two-way factorial ANOVAs and non-parametric, multivariate analyses to determine differences in growth promotion among samples. Soybean amended with PAMW1 has greater shoot mass, biomass, and height than other treatments. Through nonmetric multidimensional scaling (NMS), samples amended with a mixed culture or PAMW1 may be different regarding growth promotion relative to the non-amended samples. Univariate results support the hypothesis that the novel Pseudomonas spp. benefit soybean in a field setting. However, it is inconclusive whether a mixed culture amendment of multiple strains alters the overall growth promotion of soybean compared to samples amended with isolated strains. / Master of Science / Soil hosts a relatively abundant and diverse community of microorganisms. Moreover, the area of soil that interacts closely with plant roots and their associated exudates, called the rhizosphere, has a significantly greater microbial abundance than surrounding bulk soil. Interactions between microbes and the plant often promote plant growth because of secondary metabolites produced by these beneficial microbes. One particular bacterial species, belonging to the Pseudomonas genus, was discovered and extracted from the soybean nodule interior. Nitrogen-fixing bacteria predominantly reside in the soybean nodule, yet this microorganism cannot fix nitrogen. Although trace amounts of non-nitrogen-fixing bacteria reside in the soybean nodule, this novel species has a relatively high abundance. This study determines the benefits of this species in the soybean nodule. Following positive results in a greenhouse study, this field experiment observes variance in soybean growth and productivity based on their received bacterial amendment. For this study, two soybean cultivars were either amended with an isolated strain of this species, a mix of the two strains, or left uninoculated to serve as a control. Numerous recorded measurements serve as indices of soybean growth and productivity. The results suggest that this novel Pseudomonas species benefits the plant by significantly improving biomass. With further research, this species can potentially serve as an environmentally sensitive and sustainable alternative to fertilizers through its ability to promote soybean growth.

La composition phénolique du vin rouge détermine fortement sa qualité: couleur, goût, texture et la plupart des bienfaits pour la santé. Les conditions ambiantes de la vigne modulent l'équilibre hormonal endogène et l'expression de gènes qui contrôlent la voie de synthèse des composés flavonoïdes, en déterminant la composition phénolique finale du raisin. Même s'ils ont été étudiés, les effets des applications des régulateurs de croissance végétale sur l'équilibre hormonal endogène et la qualité du raisin, les effets de ces substances sur la composition et la qualité du vin sont pauvrement documentés. Le traitement des raisins destinés à la vinification avec des régulateurs de croissance végétale est un outil potentiel pour modifier la qualité des raisins et du vin rouge. Ce projet de thèse a pour objectif d’étudier l’impact d'applications de régulateur de croissance végétale sur la composition phénolique des raisins de Vitis vinifera L. cépages Cabernet Sauvignon et Carménère. L’acide abscissique, l’acide indole-3-acétique et l'acide 2-chloroethilphosphonique ont été appliqués à divers stades phénologiques du raisin, doses et conditions environnementales: Les essais ont été menés à Maipo et Cachapoal au Chili et à Bordeaux en France, dans des vignobles commerciaux et expérimentaux ainsi que sur des plantes cultivées en pots. Il a été examiné l'effet de ces traitements sur le contenu interne d'hormones, sur l'expression de gènes structuraux et régulateurs de la synthèse de composés flavonoides et sur la qualité des raisins, en particulier la composition phénolique de sa pellicule. De plus, des vinifications ont été réalisées à partir de raisins traités pour déterminer l'effet des traitements sur la composition chimique et phénolique du vin, ainsi que sur des attributs qualitatifs tels que les arômes et la texture des vins, jugés par un panel d'évaluation sensorielle. / Phenolic composition strongly determines red wine quality: color, taste, texture and most health benefits. Vineyard environmental conditions modulate endogenous hormonal balance and gene expression which control the flavonoid biosynthetic pathway leading to final grape phenolic composition. Even when the effects of plant growth regulator applications on grape endogenous hormonal balance and quality have been studied, the effect of these substances on wine composition and quality is poorly documented. The treatment of wine grapes with plant growth regulators is a potential tool in order to modify red wine phenolic composition and quality. This thesis project describes six experiments on plant growth regulator applications on developing grapes of Vitis vinifera L., cvs Cabernet Sauvignon and Carménère. Abscisic acid, Indole-3-acetic acid and 2-chloroethylphosphonic acid were applied in different phenological stages, doses and environmental conditions: Maipo and Cachapoal regions in Chile and Bordeaux region in France, commercial and experimental vineyards and plants in containers. The effect on changes in the internal hormonal content, expression of flavonoid biosynthetic and regulatory genes and grape quality, in particular grape skin phenolic composition were examined. In addition, winemaking was performed in order to assess the effect of treatments on wine chemical and phenolic composition and on wine aroma and texture attributes judged by a sensory panel.