Caracterização funcional de dois cDNAs homólogos à ciclofilina e à proteína reprimida por auxina (ARP) identificados em bibliotecas subtrativas a para floração em tomateiro

Flowering is a fundamental process in the life cycle for plant. This process is marked by vegetative to reproductive apical meristem conversion, due to interactions between several factors, both internal and external to plant. Therefore, eight subtractive libraries were constructed using apical meristem induced or not induced for two contrasting species: Solanum lycopersicum cv. Micro-Tom and Solanum pimpinellifolium. Several cDNAs were identified and among these, were selected two cDNAs: one homologous cDNA to cyclophilin (LeCYP1) and the other to Auxin repressed protein (ARP). It has observed that LeCYP1 and ARP genes are important in the developmental process to plants. In silico analysis, were used several databases with the exclusion criterion E-value <1.0x10-15. As a result, conservation was observed for proteins analyzed by means of multiple alignments and the presence of functional domains. Then, overexpression cassettes were constructed for the ARP cDNA in sense and antisense orientations. For this step, it was used the CaMV35S promoter. The cDNA orientation (sense or antisense) in relation to the promoter was determined by restriction enzymes and sequencing. Then, this cassette was transferred to binary vector pZP211 and these cassettes were transferred into Agrobacterium tumefaciens LBA4404. S. lycopersicum cv. Micro-Tom (MT) and MT-Rg1 plants were transformed. In addition, seedlings were subjected to hormone treatments using a synthetic auxin (- naphthalene acetic acid) and cyclosporin A (cyclophilin inhibitor) treatments and it was found that the hormone treatment there were changes in development of lateral roots pattern, probably related to decreases in auxin signaling caused by reduction of LeCYP1 in MT-dgt plants while cyclosporin A treatments, there was a slight delay in flowering in cv. MT plants. Furthermore, assay with real-time PCR (RT-qPCR) were done for expression level analysis from LeCYP1 and ARP in order to functionally characterize these sequences in tomato plants.

Análise filogenética e funcional de dois genes de reparo homólogos a AP endonuclease em cana-de-açúcar: ScARP1 e ScARP3

The genome of all organisms constantly suffers the influence of mutagenic factors from endogenous and/or exogenous origin, which may result in damage for the genome. In order to keep the genome integrity there are different DNA repair pathway to detect and correct these lesions. In relation to the plants as being sessile organisms, they are exposed to this damage frequently. The Base Excision DNA Repair (BER) is responsible to detect and repair oxidative lesions. Previous work in sugarcane identified two sequences that were homologous to Arabidopsis thaliana: ScARP1 ScARP3. These two sequences were homologous to AP endonuclease from BER pathway. Then, the aim of this work was to characterize these two sequence using different approaches: phylogenetic analysis, in silico protein organelle localization and by Nicotiana tabacum transgenic plants with overexpression cassette. The in silico data obtained showed a duplication of this sequence in sugarcane and Poaceae probably by a WGD event. Furthermore, in silico analysis showed a new localization in nuclei for ScARP1 protein. The data obtained with transgenic plants showed a change in development and morphology. Transgenic plants had slow development when compared to plants not transformed. Then, these results allowed us to understand better the potential role of this sequence in sugarcane and in plants in general. More work is important to be done in order to confirm the protein localization and protein characterization for ScARP1 and ScARP3

Influência de fatores ambientais na incidência do vírus da infecção hipodermal e necrose hematopoiética (IHHNV) no camarão Litopenaeus vannamei cultivado em fazendas do Estado do Rio Grande do Norte (RN)

The shrimp farming industry is the most profitable area of the aquaculture at Rio Grande do Norte (RN) state, which is one of the largest producers in Brazil. However the infections that affect the shrimp cause major economic losses. The infection is a result of the interaction between the shrimp, the environment and pathogen. The change of these factors may lead to a condition of stress and susceptibility to opportunistic infections. One of these infections caused by Infectious Hypodermal and Hematopoietic Necrosis Virus (IHHNV) is widely distributed in several countries and affects a wide range of hosts. To optimize conditions for production of Litopenaeus vannamei shrimp, the more species cultivated in Brazil, it is necessary to understand the effects of environmental factors in the susceptibility of this species to infections. The aim of this study was to determine the IHHNV prevalence and to investigate the influence of environmental factors as salinity, temperature, stocking density, dissolved oxygen and rainfall in the IHHNV incidence in L. vannamei grown in farms, in the RN state. To determine the IHHNV prevalence were used 1089 samples of L. vannamei collected in seven farms. To perform the study about the influence of environmental factors, 525 samples of L. vannamei shrimp were collected in eight farms located in regions of low (0-1 ), medium (21-30 ) and high (38-57 ) salinity, using extensive (≤15 shrimp/m2 ), semi-intensive (18-33 shrimp/m2) or intensive (>36 shrimp/m2) stocking density systems. The IHHNV infection was determined in pleopod and hemolymph using the polymerase chain reaction (PCR). The environmental factors were recorded during the collection of animals, using a refractometer to measure the salinity and a multi-parameter meter to measure the temperature and concentration of dissolved oxygen in the water. The IHHNV prevalence in RN was 43% (468 infected shrimp out of 1089), varying on different farms. On the seven farms studied, IHHNV prevalence ranged from 18.6% to 54.8%. The infection rates in the shrimp cultured in low, medium and high salinity were respectively 43.10% (125/290), 31.2% (15/48) and 24.6% (46/187) and was significantly higher in shrimp grown in low salinity (P<0.001). The infection rates in ponds of extensive, semi-intensive and intensive systems were respectively, 28.7%, 28.28% and 47.84%, and was significantly higher in high stocking densities (P<0.001). This study indicated a high IHHNV prevalence and a significant effect of salinity and stocking density, but not of the temperature, rainfall and dissolved oxygen on the IHHNV infection rate in the L. vannamei shrimp cultured in the northeastern Brazil

Modelagem molecular na caracterização eletrônica de oligopeptídeos e na descrição quântica da interação fármaco-receptor

In this dissertation, the theoretical principles governing the molecular modeling were applied for electronic characterization of oligopeptide α3 and its variants (5Q, 7Q)-α3, as well as in the quantum description of the interaction of the aminoglycoside hygromycin B and the 30S subunit of bacterial ribosome. In the first study, the linear and neutral dipeptides which make up the mentioned oligopeptides were modeled and then optimized for a structure of lower potential energy and appropriate dihedral angles. In this case, three subsequent geometric optimization processes, based on classical Newtonian theory, the semi-empirical and density functional theory (DFT), explore the energy landscape of each dipeptide during the search of ideal minimum energy structures. Finally, great conformers were described about its electrostatic potential, ionization energy (amino acids), and frontier molecular orbitals and hopping term. From the hopping terms described in this study, it was possible in subsequent studies to characterize the charge transport propertie of these peptides models. It envisioned a new biosensor technology capable of diagnosing amyloid diseases, related to an accumulation of misshapen proteins, based on the conductivity displayed by proteins of the patient. In a second step of this dissertation, a study carried out by quantum molecular modeling of the interaction energy of an antibiotic ribosomal aminoglicosídico on your receiver. It is known that the hygromycin B (hygB) is an aminoglycoside antibiotic that affects ribosomal translocation by direct interaction with the small subunit of the bacterial ribosome (30S), specifically with nucleotides in helix 44 of the 16S ribosomal RNA (16S rRNA). Due to strong electrostatic character of this connection, it was proposed an energetic investigation of the binding mechanism of this complex using different values of dielectric constants (ε = 0, 4, 10, 20 and 40), which have been widely used to study the electrostatic properties of biomolecules. For this, increasing radii centered on the hygB centroid were measured from the 30S-hygB crystal structure (1HNZ.pdb), and only the individual interaction energy of each enclosed nucleotide was determined for quantum calculations using molecular fractionation with conjugate caps (MFCC) strategy. It was noticed that the dielectric constants underestimated the energies of individual interactions, allowing the convergence state is achieved quickly. But only for ε = 40, the total binding energy of drug-receptor interaction is stabilized at r = 18A, which provided an appropriate binding pocket because it encompassed the main residues that interact more strongly with the hygB - C1403, C1404, G1405, A1493, G1494, U1495, U1498 and C1496. Thus, the dielectric constant ≈ 40 is ideal for the treatment of systems with many electrical charges. By comparing the individual binding energies of 16S rRNA nucleotides with the experimental tests that determine the minimum inhibitory concentration (MIC) of hygB, it is believed that those residues with high binding values generated bacterial resistance to the drug when mutated. With the same reasoning, since those with low interaction energy do not influence effectively the affinity of the hygB in its binding site, there is no loss of effectiveness if they were replaced.

Análise de cDNAs identificados em bibliotecas substrativas de cDNA para floração de variedades de cana-de-açúcar cultivadas no Rio Grande do Norte(RN): fator de transição NAC, Calmodulina e Fosfatidiltransferase

The flowering is a physiological process that it is vital for plants. This physiological process has been well studied in the plant model Arabidopsis, but in sugarcane this process is not well known. The transition of the shoot apical meristem from vegetative to flowering is a critical factor for plant development. At Brazil northeastern region, the transition to flowering in sugarcane has an important effect as it may reduce up to 60% its production. This is a consequence of the sugar translocation from stalks to the shoot apical meristem which is necessary during the flowering process. Therefore, the aim of this work was to explore and analyze cDNAs previously identified using subtractive cDNA libraries. The results showed that these cDNAs showed differential expression profile in varieties of sugarcane (early x late flowering). The in silico analysis suggested that these cDNAs had homology to calmodulin, NAC transcription factor and phosphatidylinositol, a SEC14, which were described in the literature as having a role in the process of floral development. To better understand the role of the cDNA homologous to calmodulin, tobacco plants were transformed with overexpression cassettes in sense and antissense orientation. Plants overexpressing the cassette in sense orientation did not flowered, while plants overexpressing the cassette in the antissense orientation produced flowers. The data obtained in this study suggested the possible role from CAM sequence, SEC14 and NAC in the induction/floral development pathway in sugarcane, this is the first study in order to analyze these genes in the sugarcane flowering process.

Avaliação agronômica da aplicação do resíduo da indústria processadora de goiabas em pomar comercial de goiabeiras

Dada a escassez de informações na literatura e a importância do manejo adequado de resíduos orgânicos na agricultura, objetivou-se avaliar os efeitos da aplicação do resíduo da indústria processadora de goiabas em um Argissolo Vermelho-Amarelo, determinando-se as alterações provocadas na química do solo, no estado nutricional de goiabeiras e na produção de frutos. As doses de resíduo aplicadas no pomar foram estabelecidas em função dos teores de N no resíduo. O delineamento empregado foi o de blocos casualizados, com cinco tratamentos e quatro repetições, sendo as doses do resíduo (moído) de 0, 9, 18, 27 e 36 t ha-1 (peso do material seco). Foram feitas três aplicações do resíduo: em 2006, 2007 e 2008. O resíduo da indústria processadora de goiabas promoveu aumento nos teores de P no solo; as goiabeiras apresentaram aumento dos teores de N, Ca, Mg e Mn; a produção de frutos foi alterada positiva e significativamente no terceiro ano do experimento.

Effect of intensification on grow out of the Amazon River prawn, Macrobrachium amazonicum

The effects of intensification on growth, survival, productivity, population structure, and distribution of harvested biomass in individual size classes of Macrobrachium amazonicum in semi-intensive culture were evaluated. Postlarvae (0.01 g) were stocked in 12 ponds at densities of 10, 20, 40, and 80/m(2) (three replicates per treatment) and raised for 5.5 mo. Average individual weight significantly decreased and productivity significantly increased as stocking density increased (P < 0.001), while survival was not affected (P > 0.05). Prawn mean weight at harvest ranged from 3.6 (80/m(2)) to 7.0 g (10/m(2)). Average survival ranged from 65.5% (40/m(2)) to 72.8% (20/m(2)), while productivity ranged from 508 (10/m(2)) to 2051 kg/ha (80/m(2)). Harvested biomass showed a clear bimodal distribution in individual size classes indicating the occurrence of heterogeneous growth, which may affect management and market strategies. Harvested biomass of prawns weighing more than 7 g (the best market size) increases for stocking densities up to 40/m(2) and stabilizes between 40 and 80/m(2). Growth reduction was associated with a decreasing frequency and average weight of green claw 1 and green claw 2 male morphotypes and adult females as density increased. Thus, the distribution of male morphotypes and sexually mature females are affected by density-dependent factors. Results suggest that prawn density plays an important role on M. amazonicum grow-out phase, as has been demonstrated for other species of the genus Macrobrachium. M. amazonicum tolerates grow-out intensification and may be raised in both semi-intensive and intensive systems stocked at very high densities yielding high productivity.

Host specificity of a Brazilian isolate of Alternaria cassiae (Cenargen CG593) under greenhouse conditions

Several Alternaria cassiae isolates were recovered from diseased sicklepod plants (Senna obtusifolia) in the southern regions of Brazil. A representative isolate (Cenargen CG593) was tested for its host range under greenhouse conditions. The fungus promoted symptoms in sicklepod, cassava (Manihot dulce), tomato (Lycopersicon esculentum) and eggplant (Solanum melongena) when tested at a spore concentration of 10(6) spores ml(-1). When the plants were inoculated with a suspension of 10(5) spores ml(-1) and held at a dew period of 12 h (cassava) or 18 h (tomato and eggplant), the plants showed symptoms of the disease, but they recovered and continued their normal vegetative growth. These results show that the fungus A. cassiae is safe to use for the control of S. obtusifolia under Brazilian conditions, because it did not cause excessive damage in the three plants tested.

Interferência da palha de cana-de-açúcar (Saccharum spp.) na emergência de espécies de plantas daninhas da família convolvulaceae

Este trabalho foi conduzido na Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal-UNESP, com o objetivo de estudar o efeito de diferentes quantidades de palha de cana-de-açúcar deixadas na superfície do solo sobre a emergência de algumas espécies de plantas daninhas pertencentes à família Convolvulaceae. Os tratamentos foram distribuídos no esquema de parcelas subsubdivididas, com a quantidade de palha nas parcelas de 0, 5, 10, 15 e 20 t ha-1, as variedades SP 79 2233 e RB 83 5486 nas subparcelas e as espécies de plantas daninhas nas subsubparcelas. Aos 45 dias após semeadura (DAS), a presença de 15 t ha-1 de palha reduziu em 46 e 62% o número de plantas de I. quamoclit e M. cissoides, respectivamente. Entretanto, a presença de 20 t ha-1 reduziu em 82, 65, 62, 70, 60 e 88% o número de plantas de I. quamoclit, I. purpurea, I. grandifolia, I. hederifolia, I. nil e M. cissoides, respectivamente, quando comparadas à ausência de palha.

Influência do resíduo de colheita de cana-de-açúcar sem queima sobre a eficiência dos herbicidas imazapic e imazapic + pendimethalin

Os resíduos deixados sobre o solo por ocasião da colheita mecanizada da cana-de-açúcar podem constituir-se em uma barreira física para a ação dos herbicidas no controle de plantas daninhas, quando aplicados em pré-emergência destas plantas sobre a palha da cana. em virtude disso, o presente trabalho teve por objetivos analisar e quantificar a interferência dessa camada de palha sobre o solo na ação dos herbicidas imazapic e imazapic + pendimethalin no controle de plantas daninhas em áreas onde a cana-de-açúcar foi colhida mecanicamente sem a queima da palhada previamente à colheita. Foram realizados dois ensaios simultâneos: um com a retirada da palha dois dias após a aplicação dos herbicidas e o outro com a manutenção desta, ambos conduzidos em casa de vegetação. O imazapic isolado foi aplicado nas dosagens de 0, 122,5 e 147 g i.a.ha-1 e em mistura com pendimethalin na dosagem de 75 + 1500 g i.a.ha-1, com simulação de chuvas nas intensidades de 30, 60 e 90 mm. Após análise dos resultados de biomassa seca, altura e número de folhas das plantas de Sorghum bicolor e Cyperus rotundus, além de nota visual e biomassa seca de Panicum maximum, Brachiaria plantaginea, Digitaria horizontalis, Amaranthus viridis, Ipomoea grandifolia e Brachiaria decumbens, constatou-se eficiência proporcional dos herbicidas à dosagem utilizada, independentemente da presença da palha, à exceção de Ipomoea grandifolia e Brachiaria decumbens, além de haver menor controle nos tratamentos submetidos à chuva de 90 mm. Esses resultados indicam boas perspectivas quanto à aplicação destes herbicidas em áreas de colheita mecanizada de cana-de-açúcar sem queima, para controle de plantas daninhas em condições de pré-emergência.

Efeitos da adubação fosfatada nas relações de interferência inicial entre plantas de milho (Zea mays) e de tiririca (Cyperus rotundus)

O objetivo deste trabalho foi avaliar os efeitos da adubação fosfatada nas relações de interferência inicial entre plantas de milho e de tiririca. Para isso, foi montado um experimento em vasos de 90 L, preenchidos com substrato constituído por areia, terra e substrato Plantmax®. Os tratamentos constaram de combinações de colonização dos vasos por milho e/ou por tiririca nas densidades iniciais de 25 e 50 tubérculos por vaso; essas situações de colonização foram estabelecidas em três condições de adubação fosfatada adicional: 0, 100 e 300 ppm de fósforo. No campo, os vasos foram dispostos no delineamento inteiramente casualizado, com quatro repetições. As relações de interferência entre plantas de milho e de tiririca foram alteradas pela fertilização fosfatada do solo. O milho teve excelente aproveitamento do enriquecimento do solo pelo fósforo e interferiu mais decisivamente sobre a tiririca nos vasos bem fertilizados com esse elemento. Nessas condições, o milho reduziu drasticamente a resposta da tiririca à fertilização fosfatada, em termos de crescimento da parte aérea. A interferência da tiririca reduziu a altura das plantas de milho, a expansão da área foliar e o acúmulo de matéria seca na parte aérea.

Resíduos e subprodutos agroindustriais e grãos como substratos para produção do fungo entomapatogênico Lecanicillium lecanii

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeito de doses de adubo 4-14-8 na competição entre tomateiro e Solanum americanum em convivência intra e interespecífica

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Acúmulo de massa seca e de macronutrientes por plantas de Glycine max e Solanum americanum

A soja é uma das principais culturas agrícolas do Brasil, sendo a sua produtividade muito influenciada pela competição exercida pelas plantas daninhas. Foram realizados dois experimentos em casa de vegetação, em Jaboticabal, SP, objetivando determinar o acúmulo de massa seca, assim como a distribuição e o acúmulo de macronutrientes em plantas de soja, no período de outubro de 2000 a fevereiro de 2001, e de Solanum americanum, no período de janeiro a maio de 1995. As plantas cresceram em vasos com capacidade de 7 litros, preenchidos com areia de rio lavada e peneirada; elas foram irrigadas diariamente com solução nutritiva. Os tratamentos foram representados pelas épocas de amostragem, realizada a intervalos de 14 dias, iniciando-se 21 dias após a emergência (DAE), até 161 DAE para S. americanum e 119 DAE para soja cv. BR-16 (precoce). O ponto de máximo acúmulo teórico de massa seca deu-se aos 104 DAE para a soja (35,0 g por planta) e 143 DAE para S. americanum (179,62 g por planta). da emergência até 49 e 63 DAE, as folhas apresentaram maior participação no acúmulo de massa seca para soja e S. americanum, respectivamente. Após esses períodos, verificou-se, em ambas as espécies, inversão na representatividade das folhas por caules para a espécie daninha e por caules e, posteriormente, por estruturas reprodutivas, para a cultura. A taxa de absorção diária dos macronutrientes atingiu maiores valores entre 69 e 87 DAE para a soja e entre 105 e 119 DAE para a planta daninha. Considerando a média dos valores de pontos de inflexão observados para a cultura da soja, tem-se que aos 75 DAE uma planta de soja acumula teoricamente 23,9 g de massa seca, 564,4 mg de N, 7,1 mg de P, 490,8 mg de K, 487,0 mg de Ca, 156,6 mg de Mg e 36,0 mg de S. Para o mesmo período, uma planta de S. americanum acumula teoricamente 33,75 g de massa seca, 875,96 mg de N, 88,46 mg de P, 983,54 mg de K, 647,60 mg de Ca, 100,93 mg de Mg e 42,15 mg de S.

Efeito de níveis crescentes de calagem no crescimento e estado nutricional de fedegoso

A distribuição e desenvolvimento de plantas, a exemplo daquelas que infestam as áreas agrícolas, é influenciada por diversos fatores, a como aqueles ligados às caraterísticas do solo, naturais ou impostas pelo homem. Assim, o presente trabalho de pesquisa foi desenvolvido em condições de casa-de-vegetação com o objetivo de estudar o efeito de níveis crescentes de calagem no crescimento e estado nutricional de Senna obtusifolia, planta daninha comum em ecossistemas agrícolas. O delineamento experimental adotado foi o inteiramente casualizado, com seis tratamentos e quatro repetições. Os tratamentos constituíram-se em quantidades de calcário dolomítico calcinado com 38% de CaO e 20% de MgO, com um poder de neutralização total (PRNT) de 104%: 0, 2, 4, 6, 8 e 10 t/ha. As parcelas experimentais constituíram-se de recipientes de plástico com capacidade de 5 litros, preenchidos com terra coletada na camada arável de um latossolo vermelho escuro distrófico, A moderado, textura média. Após um período de crescimento de 56 dias as plantas foram coletadas e separadas em seus componentes vegetativos, sendo colocados a secar em estufa de circulação forçada de ar (70ºC por 72 horas) para determinação do peso seco. O material foi pesado e moído e analisado a nível de composição de nutrientes. Os resultados mostraram efeitos negativos dos níveis crescentes de calcário, sobre o crescimento das plantas de S. obtusifolia, evidenciando-se decréscimos nos valores da matéria seca acumulada a partir da dose de 4 t/ha de calcário (pH 5,8), com efeitos mais marcantes nas raízes. A aplicação de doses crescentes de calcário promoveu um aumento progressivo nos teores de Ca e Mg no solo, o que talvez possa ter estimulado a competição entre cátions, reduzindo a absorção do K. Os elementos N e P foram os mais absorvidos pela planta.