Nutrição de mudas de Mimosa caesalpiniaefolia Benth. sob diferentes doses de N, P, K, Ca e Mg

http://dx.doi.org/10.5902/198050989274This work aimed to verify the concentration and accumulation of N, P, K, Ca and Mg, due to the application of increasing doses of fertilizers and to determine the critical level of these nutrients in the soil and in the plant, in seedlings of ‘sansão-do-campo’ (Mimosa caesalpiniaefolia Benth.) produced in three types of soil (mesotrophicUltisol, alic Oxisol and distrofic Oxisol). The seedlings were planted in pots with a capacity of 2.1 dm3. The experiment was conducted from December 2004 to April 2005, in Viçosa, in Minas Gerais state. The treatments were defined according to a Baconian matrix, where the macronutrients varied in three different doses and two additional treatments (zero and base), with four replications. The seedlings of ‘sansão-do-campo’ had generally a higher content of N, P, K, Ca and Mg as their availability in the soil increased. This fact was reflected in a higher content of nutrients in all parts of the plant. However, in some cases, there was no evidence of any correspondent increase for this increase. In terms of critical level, the values that provided better growth of the plant were: N (16 to 17.3 g kg-1 in the shoot), P (77 to 110 mg dm -³ in the soil and 1 to 1.5 g kg-1 in the shoot), K (51 to 86.5mg dm-3 in the soil and from 5.7 to 7.1 g kg-1 in the shoot), Ca (0.8 to 2.2cmolc dm -³ in the soil and from 10 to 14.4 g kg-1 in the shoot) and Mg (0.2 to 0.25 cmolc.dm -³ soil from 1.3 to 2.4 g kg-1 in the shoot). However, for K and Ca, studies with doses are suggested within this range of values found for better definition of the critical level. Among the soils that were studied, the Oxisol showed to be more demanding of adding nutrients, especially N and P, for an adequate production of Mimosa caesalpiniaefolia seedlings.http://dx.doi.org/10.5902/198050989274Neste trabalho, objetivou-se verificar o teor e o conteúdo de N, P, K, Ca e Mg, em razão da aplicação de crescentes doses de fertilizantes e determinar o nível crítico desses nutrientes no solo e na planta, em mudas de sansão-do-campo (Mimosa caesalpiniaefolia Benth.) produzidas em três classes de solo (Argissolo Vermelho-Amarelo mesotrófico, Latossolo Vermelho-Amarelo álico e Latossolo Vermelho-Amarelo distrófico). As mudas foram plantadas em vasos com capacidade de 2,1 dm3. O experimento foi conduzido no período de dezembro de 2004 a abril de 2005, em Viçosa, MG. Os tratamentos foram delimitados segundo uma matriz baconiana, onde variou os macronutrientes em três doses diferentes e dois tratamentos adicionais (zero e base), com quatro repetições. As mudas de sansão-do-campo, em geral, apresentaram maior conteúdo dos nutrientes N, P, K, Ca e Mg à medida que a disponibilidade destes aumentava no solo. Tal fato refletiu em maiores teores dos nutrientes em todas as partes da planta. Entretanto, em alguns casos, não houve resposta em crescimento correspondente a esse aumento. Em termos de nível crítico, os valores que proporcionaram melhor crescimento da planta foram: N (16 a 17,3 g kg-1 na parte aérea), P (77 a 110 mg dm-³ no solo e 1 a 1,5 g kg-1 na parte aérea), K (51 a 86,5 mg dm-³ no solo e 5,7 a 7,1 g kg-1 na parte aérea), Ca (0,8 a 2,2 cmolc dm-³ no solo e 10 a 14,4 g kg-1 na parte aérea) e Mg (0,2 a 0,25 cmolc dm-³ no solo 1,3 a 2,4 g kg-1 na parte aérea). Contudo, para o K e o Ca, sugerem-se estudos com doses dentro dessa faixa de valores encontrados, para melhor definição do nível crítico. Dentre os solos estudados, os Latossolos se mostraram mais exigentes de adição de nutrientes, sobretudo para N e P, para uma adequada produção de mudas de Mimosa caesalpiniaefolia.

Crescimento de mudas de garapa em resposta à calagem e ao fósforo

Este trabalho teve por objetivo avaliar o desempenho inicial da garapa (Apuleia leiocarpa (Vogel) Macbride) em condições diferenciadas de disponibilidade de fósforo (P) no solo e de saturação por bases (V). Os tratamentos foram arranjados em esquema fatorial combinando seis doses de P (0, 100, 200, 300, 400 e 500 mg dm-3) e cinco níveis de calagem empregando o critério da saturação por bases, para cálculo (original = 24, 40, 50, 60 e 70%). O delineamento foi em blocos ao acaso com cinco repetições. Aos 120 dias após a semeadura, mediram-se a altura e diâmetro do coleto de todas as plantas, as quais foram colhidas, separadas em raiz e parte aérea e secas, para obtenção de massa seca constante. Os resultados permitiram a conclusão de que o nível de calagem recomendado para a formação de mudas de garapa é aquele que proporciona a elevação da saturação por bases a 60%, sendo, nessas condições, a dose recomendada de P de 54 mg dm-3. O nível crítico de P no solo foi influenciado pelo valor da saturação por bases, variando de 6 (V = 60 %) a 33 mg dm-3 (V = 40 %). O nível crítico de P na matéria seca da parte aérea também foi influenciado pela saturação por bases, variando de 0,11 (V = 60%) a 0,18 dag kg-1 (V = 50%).This study aimed to evaluate the initial performance of Apuleia leiocarpa (Vogel) Macbride, in variable conditions of phosphorus (P) availability and base saturation (V) in the soil. The treatments were arranged in a factorial design of 6 P levels (0; 100; 200; 300; 400 and 500 mg dm-3) and 5 base saturation levels (original = 24; 40; 50; 60 and 70%), in complete randomized blocks with five replicates. Within one hundred twenty days after seed sowing, plant heights and basal stalk diameters were measured; plants were harvested, separated into roots and shoots, and dried to constant mass. The results showed that the maximum recommended lime rate for A. leiocarpa is 60% of base saturation. Under these conditions the recommended P dose is 54 mg dm-3. The P critical level in the soil was influenced by the base saturation, ranging from 6 (V = 60 %) to 33 mg dm-3 (V = 40 %). The P critical level in the shoot dry matter was also influenced by base saturation, varying from 0.11 (V = 60 %) to 0.18 dag kg-1 (V = 50 %)

Cryptococcus neoformans can form titan-like cells in vitro in response to multiple signals

Cryptococcus neoformans is an encapsulated pathogenic yeast that can change the size of the cells during infection. In particular, this process can occur by enlarging the size of the capsule without modifying the size of the cell body, or by increasing the diameter of the cell body, which is normally accompanied by an increase of the capsule too. This last process leads to the formation of cells of an abnormal enlarged size denominated titan cells. Previous works characterized titan cell formation during pulmonary infection but research on this topic has been hampered due to the difficulty to obtain them in vitro. In this work, we describe in vitro conditions (low nutrient, serum supplemented medium at neutral pH) that promote the transition from regular to titan-like cells. Moreover, addition of azide and static incubation of the cultures in a COenriched atmosphere favored cellular enlargement. This transition occurred at low cell densities, suggesting that the process was regulated by quorum sensing molecules and it was independent of the cryptococcal serotype/species. Transition to titan-like cell was impaired by pharmacological inhibition of PKC signaling pathway. Analysis of the gene expression profile during the transition to titan-like cells showed overexpression of enzymes involved in carbohydrate metabolism, as well as proteins from the coatomer complex, and related to iron metabolism. Indeed, we observed that iron limitation also induced the formation of titan cells. Our gene expression analysis also revealed other elements involved in titan cell formation, such as calnexin, whose absence resulted in appearance of abnormal large cells even in regular rich media. In summary, our work provides a new alternative method to investigate titan cell formation devoid the bioethical problems that involve animal experimentation

Paracoccidoides brasiliensis 30 kDa adhesin: identification as a 14-3-3 protein, cloning and subcellular localization in infection models

Paracoccidoides brasiliensis adhesion to lung epithelial cells is considered an essential event for the establishment of infection and different proteins participate in this process. One of these proteins is a 30 kDa adhesin, pI 4.9 that was described as a laminin ligand in previous studies, and it was more highly expressed in more virulent P. brasiliensis isolates. This protein may contribute to the virulence of this important fungal pathogen. Using Edman degradation and mass spectrometry analysis, this 30 kDa adhesin was identified as a 14-3-3 protein. These proteins are a conserved group of small acidic proteins involved in a variety of processes in eukaryotic organisms. However, the exact function of these proteins in some processes remains unknown. Thus, the goal of the present study was to characterize the role of this protein during the interaction between the fungus and its host. To achieve this goal, we cloned, expressed the 14-3-3 protein in a heterologous system and determined its subcellular localization in in vitro and in vivo infection models. Immunocytochemical analysis revealed the ubiquitous distribution of this protein in the yeast form of P. brasiliensis, with some concentration in the cytoplasm. Additionally, this 14-3-3 protein was also present in P. brasiliensis cells at the sites of infection in C57BL/6 mice intratracheally infected with P. brasiliensis yeast cells for 72 h (acute infections) and 30 days (chronic infection). An apparent increase in the levels of the 14-3-3 protein in the cell wall of the fungus was also noted during the interaction between P. brasiliensis and A549 cells, suggesting that this protein may be involved in host-parasite interactions, since inhibition assays with the protein and this antibody decreased P. brasiliensis adhesion to A549 epithelial cells. Our data may lead to a better understanding of P. brasiliensis interactions with host tissues and paracoccidioidomycosis pathogenesis.FAPESP, 2011/18038-9National Council for Scientific and Technological Development, 473119/2010-2Coordenação de Aperfeiçoamento de Pessoal de Nível Superio

Expanding tropical forest monitoring into Dry Forests: The DRYFLOR protocol for permanent plots

This is the final version. Available on open access from Wiley via the DOI in this recordSocietal Impact Statement Understanding of tropical forests has been revolutionized by monitoring in permanent plots. Data from global plot networks have transformed our knowledge of forests’ diversity, function, contribution to global biogeochemical cycles, and sensitivity to climate change. Monitoring has thus far been concentrated in rain forests. Despite increasing appreciation of their threatened status, biodiversity, and importance to the global carbon cycle, monitoring in tropical dry forests is still in its infancy. We provide a protocol for permanent monitoring plots in tropical dry forests. Expanding monitoring into dry biomes is critical for overcoming the linked challenges of climate change, land use change, and the biodiversity crisis.Newton FundNatural Environment Research Council (NERC)Fundação de Amparo à Pesquisa do Estado de São PauloCYTE

NUTRIĆÃO DE MUDAS DE MIMOSA CAESALPINIAEFOLIA BENTH. SOB DIFERENTES DOSES DE N, P, K, Ca e Mg

This work aimed to verify the concentration and accumulation of N, P, K, Ca and Mg, due to the application of increasing doses of fertilizers and to determine the critical level of these nutrients in the soil and in the plant, in seedlings of 'sansão-do-campo' ( Mimosa Caesalpiniaefolia Benth.) produced in three types of soil (mesotrophicUltisol, alic Oxisol and distrofic Oxisol). The seedlings were planted in pots with a capacity of 2.1 dm3. The experiment was conducted from December 2004 to April 2005, in Viçosa, in Minas Gerais state. The treatments were defined according to a Baconian matrix, where the macronutrients varied in three different doses and two additional treatments (zero and base), with four replications. The seedlings of 'sansãodo-camp' had generally a higher content of N, P, K, Ca and Mg as their availability in the soil increased. This fact was reflected in a higher content of nutrients in all parts of the plant. However, in some cases, there cresciwas no evidence of any correspondent increase for this increase. In terms of critical level, the values that provided better growth of the plant were: N (16 to 17.3 g kg-1 in the shoot), P (77 to 110 mg dm-3 in the soil and 1 to 1.5 g kg-1 in the shoot), K (51 to 86.5 mg dm-3 in the soil and from 5.7 to 7.1 g kg-1 in th e shoot), Ca (0.8 to 2.2 cmolc dm-3 in the soil and from 10 to 14.4 g kg-1 in the shoot) and Mg (0.2 to 0.25 cmolc dm-3 soil from 1.3 to 2.4 g kg-1 in the shoot). However, for K and Ca, studies with doses are suggested within this range of values found for better definition of the critical level. Among the soils that were studied, the Oxisol showed to be more demanding of adding nutrients, especially N and P, for an adequate production of Mimosa caesalpiniaefolia seedlings.Neste trabalho, objetivou-se verificar o teor e o conteúdo de N, P, K, Ca e Mg, em razão da aplicação de crescentes doses de fertilizantes e determinar o nível crítico desses nutrientes no solo e na planta, em mudas de sansão-do-campo ( Mimosa Caesalpiniaefolia Benth.) produzidas em três classes de solo (Argissolo Vermelho-Amarelo mesotrófico, Latossolo Vermelho-Amarelo álico e Latossolo Vermelho-Amarelo distrófico). As mudas foram plantadas em vasos com capacidade de 2,1 dm3. O experimento foi conduzido no período de dezembro de 2004 a abril de 2005, em Viçosa, MG. Os tratamentos foram delimitados segundo uma matriz baconiana, onde variou os macronutrientes em três doses diferentes e dois tratamentos adicionais (zero e base), com quatro repetições. As mudas de sansão-do-campo, em geral, apresentaram maior conteúdo dos nutrientes N, P, K, Ca e Mg à medida que a disponibilidade destes aumentava no solo. Tal fato refletiu em maiores teores dos nutrientes em todas as partes da planta. Entretanto, em alguns casos, não houve resposta em crescimento correspondente a esse aumento. Em termos de nível crítico, os valores que proporcionaram melhor crescimento da planta foram: N (16 a 17,3 g kg-1 na parte aérea), P (77 a 110 mg dm-3 no solo e 1 a 1,5 g kg-1 na parte aérea), K (51 a 86,5 mg dm-3 no solo e 5,7 a 7,1 g kg-1 na parte aérea), Ca (0,8 a 2,2 cmolc dm-3 no solo e 10 a 14,4 g kg-1 na parte aérea) e Mg (0,2 a 0,25 cmolc dm-3 no solo 1,3 a 2,4 g kg-1 na parte aérea). Contudo, para o K e o Ca, sugerem-se estudos com doses dentro dessa faixa de valores encontrados, para melhor definição do nível crítico. Dentre os solos estudados, os Latossolos se mostraram mais exigentes de adição de nutrientes, sobretudo para N e P, para uma adequada produção de mudas de Mimosa caesalpiniaefolia

Influência da saturação por bases e do fósforo no crescimento de mudas de angico-branco

Este trabalho teve por objetivo avaliar o desempenho de mudas da espécie angico-branco (Anadenanthera colubrina (Vell.) Brenan), em condições diferenciadas de disponibilidade de fósforo no solo e de saturação por bases. Os tratamentos foram representados por um fatorial de seis níveis de P (0, 100, 200, 300, 400 e 500 mg/dm³) por cinco níveis de saturação por bases (original = 24, 40, 50, 60 e 70%), sendo dispostos no delineamento em blocos ao acaso, com cinco repetições. Aos 170 dias após a semeadura, foram feitas medições de altura e diâmetro do coleto de todas as plantas, as quais foram colhidas, separadas em raiz e parte aérea e postas a secar para obtenção do peso de matéria seca. A adição da mistura corretiva ao substrato não apresentou resposta significativa por parte da espécie estudada. Essa falta de resposta pode estar relacionada ao fato de que os teores de Ca (0,9 cmol c/dm³) e de Mg (0,4 cmol c/dm³) contidos no solo utilizado tenham sido suficientes para suprir as necessidades das plantas nessa fase. No entanto, observou-se que o angico-branco responde positivamente à aplicação de P. Considerando-se a saturação por bases de 40 e 60%, as doses de P que proporcionaram 90% de produção máxima, com base na produção de matéria seca da parte aérea, foram de 127 e 126 mg/dm³, respectivamente. De acordo com o modelo ajustado para P recuperado, em função do P adicionado, a dose que proporcionará essa disponibilidade de fósforo aos 170 dias é de 976,2 mg/dm³ para V=40% e de 1.277,3 mg/dm³ para V=60%. O nível crítico de P no solo, pelo extrator Mehlich-1, foi de 13,88 mg/dm³ (V=40%) e de 12,87 mg/dm³ (V=60%) e na parte aérea, de 0,14 dag/kg (V=40%) e de 0,12 dag/kg (V=60%)