As disponibilidades de fósforo e zinco afetam as características estruturais, fisiológicas, metabólicas e produtivas das plantas, com reflexos no estabelecimento e produção de forragem da gramínea forrageira. Objetivou-se identificar e quantificar as alterações nas concentrações foliares de fósforo e zinco, trocas gasosas, concentração do aminoácido triptofano, atividade da enzima fosfatase ácida, área foliar, números de folhas e de perfilhos, sistema radicular e massa de forragem da Brachiaria brizantha cv. Marandu, em resposta ao suprimento de fósforo e zinco. O estudo foi conduzido em casa de vegetação, em Piracicaba (SP), Brasil, no período de janeiro a abril de 2010. Foram avaliadas as combinações de cinco doses de fósforo (0,1; 0,6; 1,1; 1,6 e 2,1 mmol L-1) com cinco doses de zinco (0,00; 0,75; 1,50; 2,25 e 3,00 µmol L-1), em solução nutritiva, em fatorial 52 fracionado. O delineamento experimental foi o de blocos aleatorizados, com quatro repetições. Realizaram-se duas colheitas do capim-marandu, sendo a primeira aos 38 dias após o transplantio e a segunda aos 30 dias da rebrotação. O fornecimento de fósforo propiciou incremento na taxa fotossintética foliar e na condutância estomática e decréscimo na concentração de CO2 intercelular, no segundo período de crescimento do capim-marandu. A concentração foliar de nitrogênio não foi limitante ao desenvolvimento das plantas, durante todo o experimento. A disponibilidade de zinco resultou em aumento da concentração de triptofano, no segundo período de crescimento da gramínea forrageira. A atividade da enzima fosfatase ácida e o índice de utilização de fósforo diminuíram com o aumento da disponibilidade de fósforo. Os números de folhas e de perfilhos e os parâmetros radiculares ajustaram-se exponencialmente em resposta às doses de fósforo. A interação doses de fósforo x doses de zinco foi significativa para as variáveis área foliar e massa de forragem, no segundo período de crescimento do capimmarandu. A elevada eficiência de utilização de fósforo foi confirmada pela alta atividade da fosfatase ácida e o suprimento de fósforo foi determinante para o perfilhamento e desenvolvimento do sistema radicular da gramínea forrageira. As disponibilidades de fósforo e zinco afetaram a produção de forragem do capim-marandu como reflexo da alteração na área foliar do dossel. / The availability of phosphorus (P) and zinc (Zn) affects physiological, metabolic, structural and production characteristics, which can influence forage grass establishment and production. The objective of the present study was to identify and quantify changes in leaf concentrations of P and Zn, gas exchange, amino acid tryptophan concentration, acid phosphatase enzyme activity, leaf area, number of leaves and tillers, root and forage mass of Brachiaria brizantha cv. Marandu (Marandu palisadegrass), in response P and Zn supply. The experiment was carry out in a greenhouse at Piracicaba, São Paulo State, Brazil, from January to April, 2010. Five rates of P (0.1, 0.6, 1.1, 1.6 and 2.1 mmol L-1) and five rates of Zn (0.00, 0.75, 1.5, 2.25 and 3.00 µmol L-1) were tested in a 52 fractioned factorial. The experimental used was randomized block design with four replications. Plant shoots were harvested 38 d after transplanting and 30 d after the first harvest. P supply resulted in increased leaf photosynthetic rate and stomatal conductance and decrease in intercellular CO2 concentration in the second growth period of Marandu palisadegrass. The leaf concentration of nitrogen (N) was not limiting to plant development throughout the experiment. Zn supply increased the tryptophan concentration in second growth period of forage grass. The acid phosphatase enzyme activity and the P use index decreased with the increased availability of P. The number of leaves and tillers and root parameters were exponentially adjusted as a function of P rates. The interaction P rates x Zn rates was significant for the variables leaf area and forage mass in the second growth period of Marandu palisadegrass. The high P use efficiency was confirmed by the high acid phosphatase enzyme activity and the P supply was determinant for the tillering and root systems development of the forage grass. P and Zn availabilities affected the forage production of Marandu palisadegrass reflecting the change in canopy leaf area.

Este estudo teve como objetivo verificar a eficiência de dois métodos de amostragem de árvores de rua para os bairros da orla marítima da cidade de Santos. Foram empregadas a amostragem sistemática simples e a amostragem estratificada por bairros. Cinco estratos corresponderam aos bairros Ponta da Praia, Aparecida, Embaré, Boqueirão, e, o último, denominado Composto, compreendeu três bairros vizinhos, o Gonzaga, o Pompéia e o José Menino. Dos 470 quarteirões não compostos integralmente por áreas verdes e localizados na área de estudo, foram selecionados 70 para compor a amostra (14,9%) tanto da amostragem sistemática simples quanto da amostragem estratificada. A fim de estimar o parâmetro populacional que representa a abundância de árvores, utilizou-se a variável “número de árvores por quilômetro de calçada”. Foi realizado um inventário qualitativo e quantitativo no qual foram anotados o perímetro dos quarteirões (incluindo as calçadas), o número de elementos existentes (árvores e arbustos vivos ou mortos) e suas características. Os dois métodos de amostragem foram eficientes para o levantamento de árvores de ruas nos bairros da orla marítima da cidade de Santos, mas deu-se preferência para a amostragem sistemática simples, uma vez que o ganho em precisão obtido através da estratificação por bairros foi muito pequeno. Para avaliar a riqueza e a abundância das espécies e as diferenças na composição de espécies dos estratos foram calculados os índices de diversidade de Shannon e de Jaccard. As sete espécies mais freqüentes foram Inga laurina (ingá), Sapindus saponaria (saboneteira), Terminalia catappa (chapéu-de-sol), Ficus benjamina (figueira-benjamin), Delonix regia (flamboyant), Lagerstroemia indica (resedá ou extremosa) e Callophyllum brasiliensis (guanandí). De cada um dos 1282 elementos vivos avaliados foram levantadas características relacionadas ao tamanho das árvores, ao tipo de condução ou poda, à qualidade da copa e do tronco, à fitossanidade, à compatibilidade com o local de plantio, à área livre de pavimentação, aos danos aos passeios e à presença de redes aéreas e de obstáculos ao desenvolvimento das plantas. / The aim of the present study is to examine the efficiency of two sampling methods for street trees inventory in the coastal neighborhoods of the city of Santos. Two methods have been employed: the simple systematic sampling and the stratification according to neighborhood. The five strata which have been analyzed correspond to the following neighborhoods: Ponta da Praia, Aparecida, Embaré, Boqueirão and one strata hereby called Compound, which actually comprehends three adjacent neighborhoods, namely Gonzaga, Pompéia and José Menino. Of the 470 blocks not entirely made up of green areas witch still situated in the study area, 70 have been selected to be the sample (14.9%), in the simple systematic method as well as in the stratified type. In order to estimate the population parameter representing the abundance of trees, the variable “number of trees per kilometer of sidewalk” has been utilized. A qualitative as well as a quantitative inventory has been drawn up in which we have annotated the perimeter of the blocks (sidewalks included), the number of existing elements (trees, bushes and shrubs, either dead or living) and their characteristics. Although both methods of sampling have proven to be efficient for street trees inventories in the coastal neighborhoods of the city of Santos, we have given preference to the simple systematic sampling type, since very little gain in accuracy has been obtained from the sampling method of stratification by neighborhood. So as to estimate the wealth and abundance of the species and the differences in the species composition between the five strata, we have calculated both Shannon and Jaccard diversity indexes. The seven most frequent species are the following ones: Inga laurina (ingá), Sapindus saponaria (saboneteira), Terminalia catappa (chapéu-de-sol), Ficus benjamina (figueira-benjamin), Delonix regia (flamboyant), Lagerstroemia indica (resedá or extremosa) and Callophyllum brasiliensis (guanandí). Of each of the 1.282 evaluated living elements, we have registered characteristics related to the following aspects: tree size, type of conduction or pruning, quality of crown and trunk, insect or disease problems, degree of compatibility with the planted site, areas devoid of paving, damage caused to pavements and the presence of wiring and cables or any obstacles to plant development.

As disponibilidades de fósforo e zinco afetam as características estruturais, fisiológicas, metabólicas e produtivas das plantas, com reflexos no estabelecimento e produção de forragem da gramínea forrageira. Objetivou-se identificar e quantificar as alterações nas concentrações foliares de fósforo e zinco, trocas gasosas, concentração do aminoácido triptofano, atividade da enzima fosfatase ácida, área foliar, números de folhas e de perfilhos, sistema radicular e massa de forragem da Brachiaria brizantha cv. Marandu, em resposta ao suprimento de fósforo e zinco. O estudo foi conduzido em casa de vegetação, em Piracicaba (SP), Brasil, no período de janeiro a abril de 2010. Foram avaliadas as combinações de cinco doses de fósforo (0,1; 0,6; 1,1; 1,6 e 2,1 mmol L-1) com cinco doses de zinco (0,00; 0,75; 1,50; 2,25 e 3,00 µmol L-1), em solução nutritiva, em fatorial 52 fracionado. O delineamento experimental foi o de blocos aleatorizados, com quatro repetições. Realizaram-se duas colheitas do capim-marandu, sendo a primeira aos 38 dias após o transplantio e a segunda aos 30 dias da rebrotação. O fornecimento de fósforo propiciou incremento na taxa fotossintética foliar e na condutância estomática e decréscimo na concentração de CO2 intercelular, no segundo período de crescimento do capim-marandu. A concentração foliar de nitrogênio não foi limitante ao desenvolvimento das plantas, durante todo o experimento. A disponibilidade de zinco resultou em aumento da concentração de triptofano, no segundo período de crescimento da gramínea forrageira. A atividade da enzima fosfatase ácida e o índice de utilização de fósforo diminuíram com o aumento da disponibilidade de fósforo. Os números de folhas e de perfilhos e os parâmetros radiculares ajustaram-se exponencialmente em resposta às doses de fósforo. A interação doses de fósforo x doses de zinco foi significativa para as variáveis área foliar e massa de forragem, no segundo período de crescimento do capimmarandu. A elevada eficiência de utilização de fósforo foi confirmada pela alta atividade da fosfatase ácida e o suprimento de fósforo foi determinante para o perfilhamento e desenvolvimento do sistema radicular da gramínea forrageira. As disponibilidades de fósforo e zinco afetaram a produção de forragem do capim-marandu como reflexo da alteração na área foliar do dossel. / The availability of phosphorus (P) and zinc (Zn) affects physiological, metabolic, structural and production characteristics, which can influence forage grass establishment and production. The objective of the present study was to identify and quantify changes in leaf concentrations of P and Zn, gas exchange, amino acid tryptophan concentration, acid phosphatase enzyme activity, leaf area, number of leaves and tillers, root and forage mass of Brachiaria brizantha cv. Marandu (Marandu palisadegrass), in response P and Zn supply. The experiment was carry out in a greenhouse at Piracicaba, São Paulo State, Brazil, from January to April, 2010. Five rates of P (0.1, 0.6, 1.1, 1.6 and 2.1 mmol L-1) and five rates of Zn (0.00, 0.75, 1.5, 2.25 and 3.00 µmol L-1) were tested in a 52 fractioned factorial. The experimental used was randomized block design with four replications. Plant shoots were harvested 38 d after transplanting and 30 d after the first harvest. P supply resulted in increased leaf photosynthetic rate and stomatal conductance and decrease in intercellular CO2 concentration in the second growth period of Marandu palisadegrass. The leaf concentration of nitrogen (N) was not limiting to plant development throughout the experiment. Zn supply increased the tryptophan concentration in second growth period of forage grass. The acid phosphatase enzyme activity and the P use index decreased with the increased availability of P. The number of leaves and tillers and root parameters were exponentially adjusted as a function of P rates. The interaction P rates x Zn rates was significant for the variables leaf area and forage mass in the second growth period of Marandu palisadegrass. The high P use efficiency was confirmed by the high acid phosphatase enzyme activity and the P supply was determinant for the tillering and root systems development of the forage grass. P and Zn availabilities affected the forage production of Marandu palisadegrass reflecting the change in canopy leaf area.

Este estudo teve como objetivo verificar a eficiência de dois métodos de amostragem de árvores de rua para os bairros da orla marítima da cidade de Santos. Foram empregadas a amostragem sistemática simples e a amostragem estratificada por bairros. Cinco estratos corresponderam aos bairros Ponta da Praia, Aparecida, Embaré, Boqueirão, e, o último, denominado Composto, compreendeu três bairros vizinhos, o Gonzaga, o Pompéia e o José Menino. Dos 470 quarteirões não compostos integralmente por áreas verdes e localizados na área de estudo, foram selecionados 70 para compor a amostra (14,9%) tanto da amostragem sistemática simples quanto da amostragem estratificada. A fim de estimar o parâmetro populacional que representa a abundância de árvores, utilizou-se a variável "número de árvores por quilômetro de calçada". Foi realizado um inventário qualitativo e quantitativo no qual foram anotados o perímetro dos quarteirões (incluindo as calçadas), o número de elementos existentes (árvores e arbustos vivos ou mortos) e suas características. Os dois métodos de amostragem foram eficientes para o levantamento de árvores de ruas nos bairros da orla marítima da cidade de Santos, mas deu-se preferência para a amostragem sistemática simples, uma vez que o ganho em precisão obtido através da estratificação por bairros foi muito pequeno. Para avaliar a riqueza e a abundância das espécies e as diferenças na composição de espécies dos estratos foram calculados os índices de diversidade de Shannon e de Jaccard. As sete espécies mais freqüentes foram Inga laurina (ingá), Sapindus saponaria (saboneteira), Terminalia catappa (chapéu-de-sol), Ficus benjamina (figueira-benjamin), Delonix regia (flamboyant), Lagerstroemia indica (resedá ou extremosa) e Callophyllum brasiliensis (guanandí). De cada um dos 1282 elementos vivos avaliados foram levantadas características relacionadas ao tamanho das árvores, ao tipo de condução ou poda, à qualidade da copa e do tronco, à fitossanidade, à compatibilidade com o local de plantio, à área livre de pavimentação, aos danos aos passeios e à presença de redes aéreas e de obstáculos ao desenvolvimento das plantas. / The aim of the present study is to examine the efficiency of two sampling methods for street trees inventory in the coastal neighborhoods of the city of Santos. Two methods have been employed: the simple systematic sampling and the stratification according to neighborhood. The five strata which have been analyzed correspond to the following neighborhoods: Ponta da Praia, Aparecida, Embaré, Boqueirão and one strata hereby called Compound, which actually comprehends three adjacent neighborhoods, namely Gonzaga, Pompéia and José Menino. Of the 470 blocks not entirely made up of green areas witch still situated in the study area, 70 have been selected to be the sample (14.9%), in the simple systematic method as well as in the stratified type. In order to estimate the population parameter representing the abundance of trees, the variable "number of trees per kilometer of sidewalk" has been utilized. A qualitative as well as a quantitative inventory has been drawn up in which we have annotated the perimeter of the blocks (sidewalks included), the number of existing elements (trees, bushes and shrubs, either dead or living) and their characteristics. Although both methods of sampling have proven to be efficient for street trees inventories in the coastal neighborhoods of the city of Santos, we have given preference to the simple systematic sampling type, since very little gain in accuracy has been obtained from the sampling method of stratification by neighborhood. So as to estimate the wealth and abundance of the species and the differences in the species composition between the five strata, we have calculated both Shannon and Jaccard diversity indexes. The seven most frequent species are the following ones: Inga laurina (ingá), Sapindus saponaria (saboneteira), Terminalia catappa (chapéu-de-sol), Ficus benjamina (figueira-benjamin), Delonix regia (flamboyant), Lagerstroemia indica (resedá or extremosa) and Callophyllum brasiliensis (guanandí). Of each of the 1.282 evaluated living elements, we have registered characteristics related to the following aspects: tree size, type of conduction or pruning, quality of crown and trunk, insect or disease problems, degree of compatibility with the planted site, areas devoid of paving, damage caused to pavements and the presence of wiring and cables or any obstacles to plant development.

Herbivory, fact of animals feeding all, exudations, tissues or parts of plants, is pointed like one of the most important points in the vegetation structuralization and diversity. That can be influenced by some factors, the most importants are seasonality, spatial variation, environment and plant-herbivory-predator interactions. Native species from Cerrado are also influenced by fire. In response to herbivory attack, the plants have different defenses strategies, it can be chemical, physical and/or biotic. The aim of this study was analyze the impact of herbivory action in Chamaecrista neesiana (Caesalpinoidea), in pre and post natural burn periods, trying to understand the phenologic variation importance to the plant in response to herbivory and fire damage. The study was conducted in Clube Caça e Pesca Itororó de Uberlândia, Uberlândia-MG, in two stages. Firstly, pre-fire (June to September, 2004) and the second, post-fire (November, 2004 to February, 2005). The Burn occurred accidentally in the study reserve in October, 2004. For the study was marked 46 plants of Chamaecrista neesiana (Caesalpinoidea) shared in two groups: the Control one (n=21; without herbivorous insects removal) and the Treatment one (n=25; with herbivorous insects removal). On the plants with herbivorous removal was sprayed weekly a non-nitrogen and non-phophorus based insecticide. This kind of insecticide was used to do not have plants unnatural fertilization. The application of the insecticide occurs by covering the plants with a plastic during five minutes for, more than neighbor plants protection, increases the product effectiveness. The removal of herbivorous insects in Treatment Group occurs also by manual removal. The insects were also collected in non-marked plants, by the beating method and manual collection. The herbivory was measured monthly by visual measure, using a Grid for comparison by the virtual sharing, in eight parts, on the leaf of C. neesiana. Monthly was also observed the phenology dates, the vertical and lateral growing. On the young leafs was observed a lot of oil gland, to verify their function was get on 20 control pitfalls with water and detergent and others 20 was dirty on the edge of the pitfalls with this oil. The herbivory tax was smaller in the protected against herbivorous insects group than the non-protected one, and after the burn. We suggest that this fact occur because of the higher production of young leafs after burn, that happens because in the young leafs have the oil gland production, and we found that this oil gland works like a natural defense by insects, by the collection of more abundance in pitfalls without oil. On this way, was verified more susceptibility to foliar herbivory in mature stages. In C. neesiana, was not found compensatory effect of herbivory, because the vertical and lateral growing do not differ in the both groups (with and without herbivorous insect removal). The phenology showed the boom during the dry season (pre-fire), in the same period of the biggest diversity of insects, and in response to fire the flowering was anticipate in the years 2003 and 2005 (after burning) and occurred gradually, differently the year 2005 (before burning) that the flowering occurred in boom. / A herbivoria, fato de animais se alimentarem do todo, de exsudações, de tecidos ou partes de plantas, é apontada como um ponto importante na estruturação e diversidade da vegetação. Esta pode ser influenciada por diversos fatores dentre eles destacam-se a sazonalidade, a variação espacial, o ambiente e as interações planta-herbívoro-predador. Espécies nativas do Cerrado são, também, influenciadas pelo fogo. Como resposta ao ataque de herbívoros, as plantas apresentam diferentes estratégias de defesa, podendo ser químicas, físicas e/ou bióticas. O objetivo principal desse estudo foi avaliar o impacto da ação de herbívoros em Chamaecrista neesiana (Caesalpinoidea), nos períodos pré e pós-queimada natural, buscando compreender o papel da variação fenológica da planta em resposta à herbivoria e à ação do fogo. O estudo foi realizado no Clube Caça e Pesca Itororó de Uberlândia, Uberlândia-MG, em duas etapas. A primeira, pré-fogo (Junho a Setembro de 2004) e a segunda, pós-fogo (Novembro de 2004 a Fevereiro de 2005). A queimada ocorreu de forma acidental na reserva de estudo no mês de outubro de 2004. Foram marcadas para o estudo 46 plantas de Chamaecrista neesiana (Caesalpinoidea) divididas em dois grupos: um Grupo Controle (n=21; sem remoção de herbívoros) e o outro Grupo Tratamento (n=25; com remoção de herbívoros). A remoção de herbívoros foi feita pela aplicação semanal de inseticida, não contendendo compostos à base de nitrogênio ou fósforo para que não houvesse adubação involuntária das plantas. A aplicação do inseticida se deu com o ensacamento das plantas durante cinco minutos para, além de proteger plantas vizinhas, aumentar a eficácia do produto. Houve também a remoção manual dos insetos no Grupo Tratamento. Insetos também foram coletados em plantas não marcadas, através dos procedimentos de batimento e coleta manual. Foi feita a medida visual mensal da herbivoria, utilizando-se um Grid de comparação pela divisão virtual em oito pedaços dos folíolos de C. neesiana. Mensalmente observaram-se, também, os dados fenológicos, bem como os crescimentos vertical e lateral. Foi observada a presença de glândulas de óleo em folhas jovens, para verificar sua função foram montados 20 armadilhas contendo somente água e detergente em seu interior e outras 20 foram lambuzadas nas bordas com o óleo de folhas jovens. A taxa de herbivoria foi menor no grupo protegido contra ação de herbívoros bem como após a queima, sugerimos que este fato se deve à maior produção de folhas jovens após a queimada, pois em folhas jovens há a produção de glândulas de óleo, as quais constatou-se servirem como defesa aos insetos, pela coleta de maior abundância em armadilhas sem óleo. Desta forma, constatou-se que há maior suseptibilidade a herbivoria foliar nos estágios mais maduros. Não houve efeito compensatório da herbivoria em C. neesiana, pois seu crescimento vertical e horizontal não diferiu nos grupos (remoção ou não de herbívoros). Em relação à fenologia C. neesiana, apresentou seu pico de floração durante a estação seca (pré-fogo), coincidindo com a maior diversidade de insetos, como resposta ao fogo houve antecipação da floração após a queima nos anod de 2003 e 2005 (depois do fogo) e oco / Mestre em Ecologia e Conservação de Recursos Naturais

Inseticidas e fungicidas geralmente são estudados quanto a sua eficiência no controle de pragas e doenças, entretanto podem provocar efeitos fisiológicos pouco conhecidos capazes de influenciar o desenvolvimento das culturas. O tiametoxam é um inseticida sistêmico do grupo dos neonicotinóides, da família nitroguanidina, que atua no receptor nicotínico acetilcolina de insetos, danificando o sistema nervoso dos mesmos, levando-os à morte. Este inseticida, largamente utilizado no controle de pragas iniciais e insetos sugadores, apresenta efeito bioativador, uma vez que mesmo na ausência da pragas, promove aumento em vigor e desenvolvimento nas plantas tratadas. Acredita-se que os efeitos do tiametoxam em plantas são indiretos, pois atuam na expressão dos genes responsáveis pela síntese e ativação de enzimas metabólicas, relacionadas ao crescimento da planta, alterando a produção de aminoácidos e precursores de hormônios vegetais. Existem alguns trabalhos com tiametoxam com o objetivo de verificar seus efeitos no metabolismo e desenvolvimento das plantas, mas os resultados ainda não são claros, evidenciando forte interação entre cultivares, épocas, condições de estresse e disponibilidade de nutrientes. Em função da grande utilização do inseticida tiametoxam na agricultura brasileira, o estudo deste agroquímico, no sentido de alterar o metabolismo e desenvolvimento de plantas, constitui-se de grande importância na agregação de informações à literatura biológica e agronômica. Os objetivos deste trabalho foram verificar o efeito da aplicação de tiametoxam em plantas de cana-de-açúcar, feijoeiro, soja, laranjeira e cafeeiro, em diferentes doses e formas de aplicação (tratamento de sementes, pulverização foliar e aplicação no solo), sobre parâmetros de desenvolvimento (área foliar, massa seca de folhas e raízes, comprimento radicular) e aspectos bioquímicos (teores foliares de nutrientes e atividade enzimática). Os experimentos foram realizados em vasos, no Horto Experimental do Departamento de Ciências Biológicas da ESALQ/USP. Concluiu-se que a aplicação de tiametoxam em pulverização foliar, em cana-deaçúcar, aumenta a área foliar e o comprimento das raízes, amplia a espessura do córtex da raiz, incrementa o diâmetro do cilindro vascular e aumenta o número de metaxilemas; em feijoeiro, em tratamento de sementes, aumenta a área foliar, a massa seca da parte aérea e a atividade da nitrato redutase em folhas e em pulverização foliar aumenta a atividade da nitrato redutase e a atividade da fenilalanina amônia-liase em folhas; em soja, em tratamento de sementes, aumenta a área foliar, massa seca e comprimento das raízes e os teores foliares de cálcio e magnésio, e em pulverização foliar, reduz os teores de fósforo e cálcio, mas aumenta os teores de potássio; em mudas de laranjeira, aplicado no solo, aumenta a área foliar, a massa seca das folhas, a massa seca do caule e ramos e a área foliar média, mas reduz os teores foliares de nitrogênio, fósforo e enxofre; em mudas de café arábica, aplicado na raiz, aumenta o número de folhas, a massa seca de raízes finas e o comprimento das raízes. / Insecticides and fungicides are often studied to their efficiency in controlling pests and diseases, however can cause physiological effects little known that can affect crop growth. Thiamethoxan is a systemic insecticide from the neonicotinoid group, nitroguanidine family, which acts on nicotinic acetylcholine receptor of insects, damaging their nervous system, leading them to death. This insecticide, that is widely used for controlling pests and sucking insects, has bioactivator effect, since even in the absence of pests, promotes an increase in vigor and development in treated plants. It is believed that the effects of thiamethoxan in plants are indirect, because it acts in the genes expression responsible for metabolic enzymes activation and synthesis, related to plant growth, by modifying amino acids and plant hormones precursors production. There is a number of studies with thiamethoxan in the way to determine the effects on metabolism and development of plants, but the results are not clear, showing strong interaction between cultivars, stress conditions and nutrient availability. Due to the wide use of the insecticide thiamethoxan in Brazilian agriculture, the study of this insecticide in order to know the metabolism changes in the plants, brings a great importance in the collection of knowledge to the agronomic and biological literature. The objectives of this study was to evaluate the effect of thiamethoxan on sugar cane, common beans, soy, orange and coffee plants with different doses and forms of application (seed treatment, foliar spray and soil application) on developmental parameters (leaf area, dry mass of leaves and roots, root length) and biochemical aspects (nutrient content and enzymatic activity). The experiments were conducted in pots in the ESALQ / USP, Experimental Field of Biological Sciences Department. It was concluded that the application of thiamethoxan as foliar spray on sugar cane, increases leaf area and root length, increases the thickness of the cortex of the root, increases the diameter of the vascular cylinder and increases the number of vessels; in bean for seed treatment, increases the leaf area, dry mass of shoots and the activity of nitrate reductase in leaves, and foliar spray increases the activity of nitrate reductase and phenylalanine ammonia-lyase in leaves; in soybean, in seeds treatment, increases leaf area, dry weight of roots, root length and foliar calcium and magnesium, and foliar spray, reduces the amount of phosphorus and calcium, but increased levels of potassium; in orange trees, applicated on the soil, increases the leaf area, leaf area average, leaves dry mass, stems and branches dry mass, but reduces the amount of nitrogen, phosphorus and sulfur in the leaf; in arabica coffee seedlings, applied at the root, increases the number of leaves, fine roots dry mass and length of roots.

TOOTH/MIR160A regulates leaf margin outgrowth in Arabidopsis thaliana Unlike animals, a striking aspect of the plant development is that they have evolved a flexible pattern of post embryonic development. This exposes them to the challenges of many biotic and abiotic signals throughout their life. So, plants have to evolve/regulate various mechanisms to modulate their growth and development for accomplishing a successful life cycle in the prevailing environmental conditions. Auxin is involved in the initiation of lateral organs at the meristem and serration development along the leaf margin (Bilsborough et al., 2011, Hay et al., 2006). These two developmental mechanisms share common molecular players. For example, CUC2 is required for the boundary formation at the SAM and also is shown to be essential for serration formation at the leaf margin. Similarly, tth shows increased leaf serration phenotype as well as defects in the positioning of flowers at the meristem. This demonstrates the functional significance of TTH-regulated ARFs in controlling auxin mediated developmental pathways. Leaves originate as small lumps of undifferentiated cells at the flanks of the shoot apical meristem which undergo several rounds division and expansion to generate the mature leaf with characteristic size, shape and leaf margin. Both, endogenous as well as environmental factors modulate the growth and development of a leaf. This is evident from the plasticity in leaf form, observed during the life time of a single plant, as well as from the diversity among closely related species living in different habitats. It is well known that pathways controlling leaf form are subjected to the effects of selection and adaptation. Leaf margin is a key feature of the final leaf shape and it contributes to the abundant diversity in leaf form. Leaf margin architecture varies quite significantly from smooth or entire margin to margins with large outgrowths (lobed margins). The evolution and ecological advantages of this diversity is a subject of intense investigation. It also provides a wonderful system to study the mechanistic details of iterative generation of repeated units, which is a common feature in producing many biological shapes. Recent advances in molecular technologies and the availability of genomic resources ushered the identification of new factors involved in leaf margin development. Our current knowledge of this developmental programme is that CUC2 establishes auxin maxima at the leaf margin by reorienting an auxin efflux carrier PIN1 which ultimately results in serration outgrowth (Bilsborough et al., 2011, Hay et al., 2006). A few missing links in this pathway are the mechanistic details of CUC2 function in reorienting PIN1 and the molecular details of auxin mediated serration outgrowth. Forward genetic screens have been valuable in characterizing a genetic pathway even in the post genomic era. An EMS mutagenesis screen was performed in this context to identify novel factors that can improve our understanding of this intricate mechanism. tooth was identified in the M2 population based on its increased leaf serration phenotype. Genetic analysis showed that tth phenotype is due to a monogenic recessive mutation. Along with increased leaf serration, tth also shows various developmental defects such as aberrant phyllotaxy, narrower cotyledons and narrower leaves. Positional cloning and sequencing analysis showed a G to A transition at the AT2G39175 locus which codes for MIR160A. The mutation is at the 7th base position of the mature miRNA sequence. Functional characterization of miRNAs by isolating mutations is hampered by their small genomic sizes. Till now, only a few miRNAs have been characterized by mutational analysis in plants (Allen et al., 2007, Baker et al., 2005, Cartolano et al., 2007, Chuck et al., 2007, Knauer et al., 2013, Nag et al., 2009, Nikovics et al., 2006). miR160-ARF10 regulatory module is shown to be required for leaf blade out growth and serration, but not leaf complexity in tomato (Hendelman et al., 2012). miR160 is coded by 3 loci in Arabidopsis, MIR160A, B and C. All three loci encode identical mature miRNA that targets 3 Auxin response factors, ARF10, 16 and 17. ARFs are the effector molecules of auxin mediated developmental programmes. Genetic analysis showed that enhanced serration outgrowth in tth is due to the up-regulation of its target genes. Here, we have identified a miRNA that negatively regulates serration outgrowth by repressing ARF10, 16 and 17 whose functional significance in regulating leaf margin development was not known previously. Extensive genetic interaction studies have shown that TTH acts in parallel to SAW-BP and MIR164-CUC pathways in regulating leaf margin development. We have also shown that CUC2 and PIN1 are absolutely essential for serration development in tth. CUC2 establishes a pattern required for the expression of ARF10 at the leaf margin. In the absence of CUC2, downstream effector molecules such as ARFs can not perform their function. arf10-2 arf16-2 could reduce, but not suppress serration outgrowth in various mutants suggesting their functional redundancy with other ARF family members. CUC2 establishes auxin maxima at the leaf margin that triggers the degradation of AUX/IAA repressors thereby relieving ARF proteins which mediate serration outgrowth. Whereas, TTH acts at the post transcriptional level for maintaining normal ARF transcript levels Role of SPYINDLY in Arabidopsis leaf margin development SPYNDLY encodes an O-linked N-acetyl glucosamine transferase that acts as a negative regulator of GA response. Consistent with its role in GA response, spy mutants show several GA dependent phenotypes such as early flowering and hyper branched trichomes. spy mutants also show several GA independent phenotypes such as aberrant phyllotaxy and smooth leaf margin. We have studied its role in regulating Arabidopsis leaf serration development. Reporter analysis of ARF10::GUS and CUC2::GUS in spy-3 revealed that SPY is not involved in establishing serration pattern. The spy-3 leaves did not show any defects during the early stages of serration development, but the mature leaves display smooth leaf margin indicating that SPY function is required for serration outgrowth. As shown in the present study, TTH regulated ARFs are also involved in serration outgrowth. Analysis of leaf margin phenotype in tth spy-3 showed that SPY activity is not required for ARF mediated serration outgrowth. Similar genetic interaction studies with SAW-BP pathway mutants showed that leaf margin out growth mediated by meristematic genes is not dependent on SPY function. Genetic interaction studies with MIR164-CUC pathway genes showed that SPY is required for serration outgrowth in these mutants. Interestingly, the cuc2-3 mutant is defective at both patterning and outgrowth of serration. The spy-3 could suppress serration out growth in cuc2-D suggesting that CUC2 mediated serration out growth is dependent on SPY activity. Protein-protein interaction studies between SPY and CUC2 are in progress to demonstrate whether SPY directly interacts with CUC2 or CUC2 derived signal to regulate serration out outgrowth. It is interesting to examine how mutations at SPY locus can abolish serration out growth mediated by CUC2, but does not affect the serration pattern, even though CUC2 is reported to be essential for both the patterning and outgrowth of serration.

While animal steroid hormones are very well known and have been studied for a long time, in plants no steroid substances were known until relatively recently. Only in the second half of the past century brassinosteroids were discovered; later on, their hormonal function in plants was confirmed. Still a lot of unknown remains as regards their function in plant cells. This paper presents in its first part the evidence that brassinosteroids control in maize (Zea mays L.) grown under field conditions not only its morphology and yield but also some developmental/reproduction characteristics like e.g. number of female inflorescences or speed of the development of male inflorescences. Particular response of a plant depends, however, on the type of applied brassinosteroid, its concentration, and last but not least also on a particular maize genotype and developmental stage of the plant during applicatin. Impact of brassinosteroids on primary photosynthetic processes in plants has not been proven under these conditions, neither on the activity of photosystem (PS) I nor on the Hill reaction. No statistically significant differences in the content of photosynthetic pigments have been found either. Another topic dealt with in this thesis is the possible protective influence of brassinosteroids on plants...

This work monitors the response of plants to the application of a solution of synthetic brassinosteroid (5-fluor-3α,17β-dihydroxy-5α-pregnan-6-on) under drought stress conditions and subsequent restoration of water availability. The response of two plant species was monitored under six-day period of cessation of watering and under six-day period of renewed optimal water supply. The experiments were carried out on plants with different type of photosynthesis - C3 plant Vicia faba L. and C4 plant Zea mays L.. For both plant species, three varieties/genotypes were used. Photosynthetic, morphological and developmental characteristics were monitored. The brassinosteroid treatment influenced more the morphological than the photosynthetic characteristics. The content of photosynthetic pigments was influenced more than the chlorophyll fluorescence parameters. The differences in morphological characteristics between individual varieties/genotypes were observed. The response to the application of brassinosteroid was observed especially for drought-sensitive variety/genotype. Application of brassinosteroid caused increase of the dry mass of leaves and roots, the height to leaf , the height of the whole plant and its increment under stress and post-stress periods in both plant species. The content of...

[ES] Las plantas necesitan acomodar su crecimiento a las condiciones ambientales. Con el objetivo de ajustar su desarrollo a las señales externas, usan una serie de mecanismos moleculares. Uno de estos son las rutas de señalización hormonal, que participan en integrar la información externa con programas de desarrollo propios. Una de las hormonas más relevantes en la biología vegetal son las giberelinas (GAs). La señalización por GAs se inicia con la percepción de la hormona a través del receptor GID1, y continúa por la degradación de las reguladoras transcripcionales DELLA. Sin embargo, solo las plantas vasculares tienen un sistema de percepción de GAs completo. Entender la relevancia de la señalización por GAs requiere estudiar cómo se ensambló la ruta y qué funciones atribuidas a las GAs estaban ya codificadas en las proteínas DELLA ancestrales. Aquí mostramos mediante análisis filogenéticos y bioquímicos que las proteínas DELLA emergieron inequívocamente en un ancestro común de las plantas terrestres, y que el reclutamiento de las DELLAs al módulo de percepción de GAs depende de la presencia de un dominio de transactivación conservado que fue co-optado por el receptor GID1 ancestral para actuar como un degrón dependiente de GAs. Este dominio de transactivación parece regular la co-activación transcripcional de genes concretos por las DELLAs en todas las plantas terrestres mediante el reclutamiento de complejos Mediator a través de su subunidad MED15. Por último, nos hemos centrado en entender las funciones de las proteínas DELLA en briófitas, un clado sin señalización por GAs. Hemos descubierto el rol de la DELLA de Marchantia polymorpha como coordinadora entre las respuestas de crecimiento y estrés, sugiriendo que dicha función estaba ya codificada en proteínas DELLA del ancestro común de plantas terrestres y se ha mantenido durante más de 450 millones de años. / [CA] Les plantes necessiten acomodar el seu creixement a les condicions ambientals. Amb l'objectiu d'ajustar el seu desenvolupament als senyals externs, usen una sèrie de mecanismes moleculars. Un d'aquests són les rutes de senyalització hormonal, que participen en integrar la informació externa amb programes de desenvolupament propis. Una de les hormones més rellevants en la biologia vegetal són les giberel·lines (GAs). La senyalització per GAs s'inicia amb la percepció de l'hormona a través del receptor GID1, i continua per la degradació de les reguladores transcripcionals DELLA. No obstant això, només les plantes vasculars tenen un sistema complet de percepció de GAs. Entendre la rellevància de la senyalització per GAs requereix estudiar com es va assemblar la ruta i quines funcions atribuïdes a les GAs estaven ja codificades en les proteïnes DELLA ancestrals. Ací mostrem mitjançant anàlisis filogenètiques i bioquímiques que les proteïnes DELLA van emergir inequívocament en un ancestre comú de les plantes terrestres, i que el reclutament de les DELLAs al mòdul de percepció de GAs depén de la presència d'un domini de transactivació conservat que va ser co-optat pel receptor GID1 ancestral per a actuar com un degró dependent de GAs. Aquest domini de transactivació sembla regular la co-activació transcripcional de gens concrets per les DELLAs en totes les plantes terrestres mitjançant el reclutament de complexos Mediator a través de la seua subunitat MED15. Finalment, ens hem centrat en entendre les funcions de les proteïnes DELLA en briòfites, un clade sense senyalització per GAs. Hem descobert el rol de la DELLA de Marchantia polymorpha com a coordinadora entre les respostes de creixement i estrés, suggerint que aquesta funció estava ja codificada en proteïnes DELLA de l'ancestre comú de plantes terrestres i s'ha mantingut durant més de 450 milions d'anys. / [EN] Plants need to accommodate their growth habits to environmental conditions. For this aim, several mechanisms are used to adjust developmental responses to exogenous signals. Among them, hormonal signalling pathways participate by integrating external information with endogenous programs. One of the most relevant hormones in plant biology are gibberellins (GAs). GA signalling involves perception of the hormone by the GA receptor GID1 and subsequent degradation of the DELLA transcriptional regulators. However, only vascular plants possess a full GA perception system. Understanding the relevance of GA signalling requires elucidating how this pathway was assembled and which of the functions attributed to GAs were encoded in the ancestral DELLA proteins. Here we show by phylogenetic and biochemical analyses that DELLA proteins emerged unequivocally in a land plant common ancestor and that their recruitment into the GA-perception module relies in the presence of a conserved transactivation domain co-opted by an ancestral GID1 receptor to act as a GA-dependent degron. Moreover, this transactivation domain seems to regulate DELLA-dependent transcriptional co-activation of selected target genes by recruitment of Mediator complexes through the MED15 subunit in all land plants. Finally, we have focused on understanding the functions of DELLA proteins in bryophytes, a clade with no GA signalling. We have uncovered the role of Marchantia polymorpha DELLA protein as a coordinator between growth and stress responses, suggesting that this function was already present in the DELLA protein of a land plant common ancestor and has been maintained for over 450 millions of years. / La realización de esta tesis doctoral ha sido posible gracias a una ayuda para contratos predoctorales FPU (FPU15/01756), dos Ayudas para Estancias Breves FPU (EST17/00237, IPS2, París; EST18/00400, WUR, Wageningen), una ayuda EMBO Short-Term (ASTF 8239, WUR, Wageningen), y la financiación MSCA H2020 RISE para desplazamientos en el contexto del proyecto SIGNAT (RISE Action 644435, PUC, Santiago). Así mismo, el grueso del trabajo experimental incluido ha sido financiado por el proyecto HUBFUN del MINECO (BFU2016-80621-P) / Hernández García, J. (2021). Ancestral Functions of DELLA Proteins [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/169370