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Search Results: 1 - 10 of 608760 matches for " Marques Teresa Cristina Lara Lanza de Sá e Melo "
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Antioxidant system of ginseng under stress by cadmium
Marques, Teresa Cristina Lara Lanza de Sá e Melo;Soares, Angela Maria;
Scientia Agricola , 2011, DOI: 10.1590/S0103-90162011000400014
Abstract: toxic levels of cd can cause protein denaturation and oxidative stress, which result in membrane damage, enzimatic activity changes and other metabolic damage. some plants may show alteration in the activity of their antioxidant enzymes as a heavy metal tolerance mechanism. this study aims at evaluating the role of enzymes of the antioxidant system in adaptive responses of the accumulator p. glomerata species to levels of cadmium (cd). plants were cultivated in nutrient solutions containing concentrations of cd in the form of cdso4 (0, 45 and 90 μmol l-1), for 20 d. cd concentrations and yields of root and shoot dry matter were determined at the end of the experiment. malondialdehyde (mda) production and the activities of antioxidant enzymes were determined after days 1, 12 and 20. higher cd concentrations in tissues of p. glomerata were found to reduce biomass production in both roots and shoots. the lipid peroxidation rates in leaves and roots were smaller at the start of the experiment for all cd levels. superoxide dismutase (sod) activity increased in leaves on day 1 and in roots on day 20 as cd levels increased. cd stress induced an increase in the activity of apx in leaves, whereas in roots ascorbate peroxidase (apx) activity was reduced at high concentration of cd. at the end of the experiment, catalase (cat) activity in leaves was reduced as cd concentration increased. nevertheless, the glutathione reductase (gr) and guaiacol peroxidase (gpx) activities increased. in roots, gr activity was reduced on days 1 and 20.
Crescimento e teor de metais de mudas de espécies arbóreas cultivadas em solo contaminado com metais pesados
Marques, Teresa Cristina Lara Lanza de Sá e Melo;Moreira, Fatima Maria de Souza;Siqueira, José Oswaldo;
Pesquisa Agropecuária Brasileira , 2000, DOI: 10.1590/S0100-204X2000000100015
Abstract: the objective of the paper was to evaluate metal content and ability to grow in soil with excess of heavy metals of seedlings of 20 woody species. in the greenhouse, seedlings were transplanted to pots with 3.3 kg of soil-mixes with different proportions (0, 20, 40, 60% v/v) of a heavy metal contaminated soil. it was found that plant species behaved differently in terms of growth inhibition and metal content in the shoots and roots. based upon the dry matter yield, only myrsine umbellata, cedrella fissilis, tabebuia impetiginosa and copaifera langsdorffii were not affected by increasing contamination, whereas hymenaea courbaril, mimosa caesalpiniaefolia, acacia mangium and platypodium gonoacantha were only slightly affected by it. all the other species were highly inhibited by the excess of metals in the soil, being such effects related, in most cases, to high uptake of zn and cd. several species were able to retain large quantities of these metals in the roots, therefore avoiding their translocation to shoots.
Crescimento e teor de metais de mudas de espécies arbóreas cultivadas em solo contaminado com metais pesados
Marques Teresa Cristina Lara Lanza de Sá e Melo,Moreira Fatima Maria de Souza,Siqueira José Oswaldo
Pesquisa Agropecuária Brasileira , 2000,
Abstract: O objetivo do trabalho foi avaliar o teor de metais pesados e o crescimento de mudas de 20 espécies arbóreas tropicais em solo com elevado grau de contamina o com metais pesados. Em casa de vegeta o, as mudas foram transplantadas para vasos contendo 3,3 kg de misturas com diferentes propor es (0, 20, 40 e 60% v/v) de solo contaminado. Verificou-se comportamento diferenciado das espécies quanto à inibi o de crescimento e aos teores de metais na raiz e na parte aérea em decorrência da contamina o. Com base na produ o de matéria seca da parte aérea, concluiu-se que apenas Myrsine umbellata, Cedrella fissilis, Tabebuia impetiginosa e Copaifera langsdorffii n o foram afetadas pela contamina o, enquanto Hymenaea courbaril, Mimosa caesalpiniaefolia, Acacia mangium e Platypodium gonoacantha sofreram pequeno impacto. As demais espécies foram muito inibidas pela contamina o do solo, o que é causado pela absor o, na maioria dos casos, de Zn e Cd. Várias espécies apresentaram elevada capacidade de reter esses metais nas raízes, evitando sua transloca o para a parte aérea.
Respostas fisiológicas e anat?micas de plantas jovens de eucalipto expostas ao cádmio
Marques, Teresa Cristina Lara Lanza de Sá e Melo;Soares, Angela Maria;Gomes, Marcelo Pedrosa;Martins, Giordane;
Revista árvore , 2011, DOI: 10.1590/S0100-67622011000600005
Abstract: pollution caused by heavy metals, mainly by cadmium (cd), is generated by mining and industrial activities, and by the use of phosphated fertilizers and sewage sludge in agriculture. aiming to investigate the cd effects on physiological and anatomical features, eucalyptus seedlings in cd-increasing concentrations in nutrient solution. seedlings of eucalyptus camaldulensis remained for 20 days in 1l vases with clark solutions, and the treatments with 0, 15, 25, 45 and 90 mmol cd l-1 supplied as cdso4. water potential, water potential and pigment content evaluations were carried out on dates 1, 3, 6, 12 and 20 days after treatments induction (dae). evaluations of mass production, cd contents and anatomical characteristics were made with vegetal matter collected in the end of the experimental period. there was a decrease on dry matter production, even in the lowest cd concentration. total chlorophyll content decreased with the increase of cd content in nutrient solution at 20 days after exposure (dae) whereas carotenoid contents were the highest at 45 and 90 mmol cd l-1. lipid peroxidation in leaves increased with increasing cd levels at 20 dae, whereas in root, the effect of cd was less pronunciated. water potential increased at all cd concentration at 12 and 20 dae. root tissues thickness also increased increased as cd levels increased, but mesophyll and leave blade thickness decreased. thus, the results indicate that the exposure time and higher doses of cd accentuate damages in e. camaldulensis for most of the evaluated traits. some changes observed reveal the tolerance potential of e. camaldulenses to cd-exposition.
Efeitos dos rejeitos da indústria de zinco na anatomia e crescimento de plantas jovens de Salix humboldtiana Willd: (salgueiro)
Gomes, Marcelo Pedrosa;Marques, Teresa Cristina Lara Lanza de Sá e Melo;Nogueira, Mariana de Oliveira Gon?alves;Silva, Guilherme Henrique;Castro, Evaristo Mauro de;Soares, ?ngela Maria;
Hoehnea , 2011, DOI: 10.1590/S2236-89062011000100012
Abstract: the heavy metal pollution caused mainly by mining and industrial activities requires studies for the recovery of contaminated areas. thus, we studied growth and anatomical characteristics responses of young willow plants grown in heavy metal multicontaminated soil. plants were grown in three mixture levels of contaminated soil: 0%, 15% and 30% (v/v) for 60 days. at the highest level of contamination was noted a less dry matter production of roots and shoots and reduced root growth. accordingly, the roots exhibited epidermis, exodermis and endodermis thicker, and a smaller number of conducting elements of xylem. leaves showed changes in the number of conducting elements of xylem diameter and density of stomata, and epidermis, endodermis, collenchyma and mesophyll cell thickness.
Ecophysiological and anatomical changes due to uptake and accumulation of heavy metal in Brachiaria decumbens
Gomes, Marcelo Pedrosa;Marques, Teresa Cristina Lara Lanza de Sá e Melo;Nogueira, Mariana de Oliveira Gon?alves;Castro, Evaristo Mauro de;Soares, ?ngela Maria;
Scientia Agricola , 2011, DOI: 10.1590/S0103-90162011000500009
Abstract: the growth and developmental characteristics of grasses and their high biodiversity make such plants suitable for remediation of areas contaminated by heavy metals. nevertheless, heavy metal toxic effect on the plants may cause alteration in their metabolic pathways, such as photosynthesis, respiration, and growth, modifying plant anatomy. this work aimed to evaluate the effect of levels of soil contamination (0, 7.5 % and 15 % m3 m-3) on biomass production, on photosynthetic characteristics and on anatomical changes in roots and leaves of brachiaria (brachiaria decumbens stapf.). after seeds were planted, seedlings were uprooted and replanted in vases containing soil at different contamination levels, being left to rest for 120 days. at the end of that time, plants presented reduced yield of root and shoot dry matter, contents of chlorophyll a, chlorophyll b, total chlorophyll and potential photosynthesis with increased of soil contamination. the cell layers of endodermis and exodermis in the root tissues and the cell walls of the xylem and cortical parenchyma all thickened as contamination increased. in the leaf tissues, the adaxial and abaxial epidermis presented increased thickness while the leaf blade presented reduced thickness as contamination increased with consequent change in the root growth rate. in general, the effects of heavy metal increased with the metal concentration. some results indicate that b. decumbens seems to have some degree of heavy metal tolerance.
Evolvimento de dióxido de carbono e mineraliza??o de nitrogênio em Latossolo Vermelho-Escuro com diferentes manejos
Pesquisa Agropecuária Brasileira , 2000, DOI: 10.1590/S0100-204X2000000300014
Abstract: the objective of this work was to verify the influence of different types of straw (maize and lablab) and soil management on evolving co2 and n mineralization. a dystrophic clayey dark-red latosol under cerrado from the region of sete lagoas, mg, brazil, was cultivated during five years with no-tillage, disc-plow and moldboard-plow. soil samples (0-20 cm) were incubated at 25oc during 55 days, with and without n fertilizer applied at the beginning and 25 days afterwards. as a general rule, the maize straw had higher rates of evolved co2 than the lablab (935 e 764 mg co2 g-1 soil, respectively). the type of straw influenced the amount of co2 evolved more than the type of soil management did. nitrogen addition increases the rate of co2 evolved only when applied at the beginning of the incubation period. the n availability and the duration of the immobilization are modified by the c/n ratio and by the type of soil management.
Evolvimento de dióxido de carbono e mineraliza o de nitrogênio em Latossolo Vermelho-Escuro com diferentes manejos
Pesquisa Agropecuária Brasileira , 2000,
Abstract: Este trabalho foi elaborado com o objetivo de verificar o efeito das palhas de milho e lab-lab, dos tipos de manejos do solo e da presen a de uma fonte externa de N, no evolvimento de CO2 e na mineraliza o de N. Usou-se um Latossolo Vermelho-Escuro distrófico textura argilosa fase cerrado, da regi o de Sete Lagoas (MG), com histórico de uso envolvendo cinco anos sob plantio direto e plantio convencional com arado de disco e arado de aiveca. Amostras de solo (0-20 cm) foram incubadas a 25oC durante 55 dias, na presen a e na ausência de palhada residual e de fonte externa de N aplicada no início e 25 dias após. De modo geral, a palhada de milho apresentou maior taxa de CO2 evolvido do que o lab-lab (935 e 764 mig CO2 g-1 solo, respectivamente). O tipo de palhada residual influenciou mais o evolvimento de CO2 do que os manejos de solo. A adi o de N aumenta a taxa de CO2 evolvida, apenas quando N é aplicado no início do período de incuba o. A disponibilidade de N e o tempo de imobiliza o s o alterados pela rela o C/N da palhada incorporada e pelo preparo do solo.
Acúmulo e distribui o de metais pesados nas raízes, caule e folhas de mudas de árvores em solo contaminado por rejeitos de indústria de zinco
Revista Brasileira de Fisiologia Vegetal , 2001,
Abstract: Avaliaram-se em casa-de-vegeta o o acúmulo e a distribui o de metais pesados nas raízes, caule e folhas de mudas de vinte espécies arbóreas tropicais crescendo em solo contaminado com metais pesados. As mudas com tamanho ideal para plantio foram transferidas para vasos contendo 3,3 kg de solo sem contamina o ou contaminado com Zn, Cd, Cu e Pb, onde permaneceram por 90 dias. As espécies que cresceram em solo contaminado apresentaram teores foliares elevados, variando de (mg kg-1): Zn = 154 a 1177; Cd = 0,6 a 54,6; e Cu = 2,8 a 134. Essas concentra es foram, em muitos casos, superiores aos níveis críticos de toxidez, ao passo que os teores foliares de Pb variaram de 0,1 a 4,3 mg kg-1, n o atingindo níveis considerados fitotóxicos. Em algumas espécies como Machaerium nictidans, Myroxylon peruiferum, Piptadenia gonoacantha, Senna macranthera e Trema micrantha, que tiveram o crescimento muito inibido pela contamina o, houve elevada transloca o de Zn e/ou Cd para parte aérea. Dendropanax cuneatum, que foi pouco afetada pelos metais, também apresentou índice elevado de transloca o de Zn e Cd, mas reteve esses elementos no caule. Acacia mangium, Copaifera langsdorffi e Cedrella fissilis também apresentaram baixa sensibilidade à contamina o e apresentaram elevado acúmulo de Zn e Cd nas raízes, indicando que a baixa transloca o desses elementos para a parte aérea está envolvida na tolerancia dessas espécies ao excesso de metais pesados no solo. O padr o de distribui o proporcional de Zn e Cd nas raízes e parte aérea das plantas se relaciona com o comportamento dessas ao excesso de metais pesados no solo.
Teresa Cristina Lara Lanza de Sá e Melo Marques,Janice Guedes de Carvalho,Mariluza Pinto Coelho Lacerda,Paulo Emílio Ferreira da Mota
CERNE , 2004,
Abstract: Macronutrients concentrations in leave, stem, and root tissues of Schizolobium amazonicum Herb. were determined under greenhouse conditions using the missing element technique. The experimental design was a completely randomized block with four replications and 13 treatments. Seedlings 0.05–0.10 -m high were planted into 3 L pots filled with nutritive solution. Based on the concentrations of macronutrients in the leaves of the complete and the deficient treatments, suitable and deficient levels (g kg-1) of macronutrients for S. amazonicum are: a) suitable: 4 for P; 15 for K; 40 for Ca; 4 for Mg; and 3 for S; 33of B; 5 of Cu; 540 of Fe, 88 of Mn; and 71 of Zn; b) critical: 1 for P; 4 for K; 8 for Ca; 1 for Mg; and 2 for S; 31 of B; 4 of Cu; 140 of Fe; 38 of Mn; and 24 of Zn
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