Arbuscular mycorrhiza confers Pb tolerance in Calopogonium mucunoides

Heavy metals (HMs) are environmental pollutants of great concern to humans because of their high potential toxicity. Lead is a HM that is present in the soil in very small amounts, but anthropogenic activities have increased its content in some locations, which can make these areas unproductive or inappropriate for crop production. However, there are some plants that can grow in contaminated soils and, thus, can be useful for the removal or stabilisation of such contaminants. In addition, plants that are not able to tolerate high concentrations of HMs in the soil can become tolerant or increase their performance when associated with arbuscular mycorrhizal (AM) fungi. Accordingly, this study was carried out to verify whether the inoculation of Glomus etunicatum, an AM fungus species, in Calopogonium mucunoides would influence plant tolerance to increasing concentrations of Pb in the soil. The experimental design was completely randomised, in a 2 x 4 factorial design, and the treatments consisted of inoculation (or not) with the AM fungus, G. etunicatum, and the addition of four Pb concentrations (0, 250, 500 or 1,000 mg kg(-1)) to the soil. The results showed that the association of C. mucunoides with G. etunicatum promoted biomass production, and nutrient uptake (P, S and Fe) was also positively influenced by mycorrhization. The malondialdehyde content was higher in non-mycorrhizal leaves, suggesting a reduction in the damage to membranes by lipid peroxidation in plants associated with mycorrhizae. However, the Pb concentration in the shoots did not differ between the mycorrhizal and non-mycorrhizal plants. The results of our study suggest that the AM symbiosis can be considered very effective in contributing to the tolerance of C. mucunoides to Pb.34252353

Lead tolerance and phytoremediation potential of Brazilian leguminous tree species at the seedling stage

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)A greenhouse pot experiment was conducted to evaluate the potential of three Brazilian leguminous woody species, Mimosa caesalpiniaefolia, Erythrina speciosa and Schizolobium parahyba, for the revegetation of lead- (Pb-) contaminated areas. The response of seedlings to increasing Pb concentrations (0, 250, 500 and 1000 mg kg(-1)) in the soil was studied. In addition to Pb accumulation and translocation, the following parameters were assessed: chlorophyll, nitrate, ammonia, lipid peroxidation (MDA) and free amino acid content; seedling growth; and nitrogenase activity. No differences were observed in the germination of woody species seeds sown in soils with or without Pb addition. M. caesalpiniaefolia did not show visual symptoms of Pb toxicity, while the other two species demonstrated stress symptoms, including reduced shoot biomass yield, leaf area and height. Biochemical analyses of plant tissues revealed markedly different responses to increasing Pb concentrations, such as changes in foliar soluble amino acid composition in S. parahyba; changes in ammonia and nitrate content in E. speciosa, M. caesalpiniaefolia and S. parahyba; and changes in MDA content in S. parahyba. The levels of chlorophyll a and b and carotenoid were affected in the species studied. For the Nitrogen-fixing (N-2-fixing) species E. speciosa, an increase of Pb in the soil affected nodule formation and growth, which led to reduced nitrogenase activity in seedlings. The concentration of Pb in shoots and roots increased with the Pb concentration in soil. However, most of the Pb absorbed accumulated in the roots, and only a small fraction was translocated to aboveground parts. These findings were confirmed by the low bio-concentration factor (BCF) and translocation factor (TF) values for the three species. The tolerance index (TI) values suggested that M. caesalpiniaefolia, a N2-fixing tree, was the species that was most tolerant to high Pb concentrations in soil, while E. speciosa and S. parahyba showed moderate tolerance. Of the three Brazilian native woody species studied, M. caesalpiniaefolia was found to have the highest Pb tolerance and phytostabilisation potential in Pb-contaminated soils. (c) 2012 Elsevier Ltd. All rights reserved.110299307Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Impairment of thrombin generation in the early phases of the host response of sepsis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Purpose: The purpose was to investigate the presence of hypercoagulability in the very early phase of the host response to an infection in the clinical course of sepsis and septic shock. Material and Methods: Twenty-four patients with chemotherapy-associated febrile neutropenia were evaluated at baseline, at the time of fever onset, and 48 hours thereafter using the thrombin generation test, a more physiological and global assay of hemostasis. Results: The rate of thrombin generation was decreased and no signals of systemic hypercoagulability could be observed during the first 48 hours of sepsis. Moreover, patients that evolved to septic shock presented a more significant impairment in thrombin generation than those with noncomplicated sepsis. Conclusions: Patients with sepsis and febrile neutropenia present an impairment in thrombin generation from very early stages of their disease course. These results suggest that the procoagulant in vitro alterations described during sepsis do not necessarily translate into a clinically relevant systemic hypercoagulable state. These findings could help explain why treatment with systemic anticoagulants did not translate to clinical benefits in human sepsis and highlight the need for a better understanding of the hemostatic alterations in sepsis before new treatments targeting coagulation activation are developed. (C) 2014 Elsevier Inc. All rights reserved.2913136Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAPESP [2011/02829-7