RESUMO
As lithium (Li) stands out as a crucial component of batteries, the inappropriate disposal of electronic gadgets might drive Li pollution in environmentally sensitive environments, such as dumps, where castor bean (Ricinus communis) plant communities are usually found. The exposure to high Li concentration is potentially harmful to the environment and humans. Therefore, it is opportune to evaluate the potential of bioindicator species to monitor Li contamination. In this scenario, the present study assessed the effects of Li exposure on the development of castor bean plants exposed to lithium chloride at five Li dosages (0, 5, 10, 20, and 30 mg dm-3). Significant symptoms of phytotoxicity were observed at all doses. Li dosage exhibited increasing impairment effects on plant biometrics, such as stem diameter and the number of leaves, as well as on the SPAD index, nutritional balance, and biomass production. Our findings suggest castor bean as a potential model species for biomonitoring Li-contaminated areas.
Assuntos
Lítio , Ricinus communis , Ricinus communis/efeitos dos fármacos , Lítio/toxicidade , Monitoramento Ambiental/métodos , Ricinus/efeitos dos fármacos , Poluentes do Solo/toxicidadeRESUMO
We determined the length, volume, dry biomass, and density in seeds of five castor bean cultivars and verified notable physicochemical trait differences. Seeds were then subjected to different toxic aluminum (Al) concentrations to evaluate germination, relative root elongation, and the role of root apices' rhizosphere mucilage layer. Seeds' physicochemical traits were associated with Al toxicity responses, and the absence of Al in cotyledons near to the embryo was revealed by Al-hematoxylin staining, indicating that Al did not induce significant germination reduction rates between cultivars. However, in the more sensitive cultivar, Al was found around the embryo, contributing to subsequent growth inhibition. After this, to investigate the role of mucilage in Al tolerance, an assay was conducted using NH4Cl to remove root mucilage before or after exposure to different Al concentrations. Sequentially, the roots were stained with hematoxylin and a quantitative analysis of staining intensity was obtained. These results revealed the significant contribution of the mucilage layer to Al toxicity responses in castor bean seedlings. Root growth elongation under Al toxicity confirmed the role of the mucilage layer, which jointly indicated the differential Al tolerance between cultivars and an efficient Al-exclusion mechanism in the tolerant cultivar.
Assuntos
Alumínio/farmacologia , Mucilagem Vegetal/fisiologia , Ricinus communis/crescimento & desenvolvimento , Sementes/crescimento & desenvolvimento , Poluentes do Solo/farmacologia , Alumínio/metabolismo , Biocombustíveis , Ricinus communis/efeitos dos fármacos , Ricinus communis/metabolismo , Fenótipo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Rizoma/efeitos dos fármacos , Rizoma/crescimento & desenvolvimento , Rizoma/metabolismo , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Plântula/metabolismo , Sementes/efeitos dos fármacos , Sementes/metabolismo , Poluentes do Solo/metabolismoRESUMO
Ricinus communis L. is of great economic importance due to the oil extracted from its seeds. Castor oil has been used for pharmaceutical and industrial applications, as a lubricant or coating agent, as a component of plastic products, as a fungicide or in the synthesis of biodiesel fuels. After oil extraction, a castor cake with a large amount of protein is obtained. However, this by-product cannot be used as animal feed due to the presence of toxic (ricin) and allergenic (2S albumin) proteins. Here, we propose two processes for detoxification and allergen inactivation of the castor cake. In addition, we establish a biological test to detect ricin and validate these detoxification processes. In this test, Vero cells were treated with ricin, and cell death was assessed by cell counting and measurement of lactate dehydrogenase activity. The limit of detection of the Vero cell assay was 10 ng/mL using a concentration of 1.6 x 10(5) cells/well. Solid-state fermentation (SSF) and treatment with calcium compounds were used as cake detoxification processes. For SSF, Aspergillus niger was grown using a castor cake as a substrate, and this cake was analyzed after 24, 48, 72, and 96 h of SSF. Ricin was eliminated after 24 h of SSF treatment. The cake was treated with 4 or 8% Ca(OH)2 or CaO, and both the toxicity and the allergenic properties were entirely abolished. A by-product free of toxicity and allergens was obtained.
Assuntos
Animais , Alérgenos/efeitos dos fármacos , Aspergillus niger/crescimento & desenvolvimento , Compostos de Cálcio/farmacologia , Ricinus communis/efeitos dos fármacos , Inativação Metabólica , Alérgenos/toxicidade , Aspergillus niger/efeitos dos fármacos , Chlorocebus aethiops , Ricinus communis/toxicidade , Morte Celular/efeitos dos fármacos , Degranulação Celular/efeitos dos fármacos , Ativação Enzimática , Fermentação , L-Lactato Desidrogenase/metabolismo , Mastócitos/efeitos dos fármacos , Ricina/isolamento & purificação , Ricina/toxicidade , Fatores de Tempo , Testes de Toxicidade , /isolamento & purificação , /toxicidade , Células VeroRESUMO
Ricinus communis L. is of great economic importance due to the oil extracted from its seeds. Castor oil has been used for pharmaceutical and industrial applications, as a lubricant or coating agent, as a component of plastic products, as a fungicide or in the synthesis of biodiesel fuels. After oil extraction, a castor cake with a large amount of protein is obtained. However, this by-product cannot be used as animal feed due to the presence of toxic (ricin) and allergenic (2S albumin) proteins. Here, we propose two processes for detoxification and allergen inactivation of the castor cake. In addition, we establish a biological test to detect ricin and validate these detoxification processes. In this test, Vero cells were treated with ricin, and cell death was assessed by cell counting and measurement of lactate dehydrogenase activity. The limit of detection of the Vero cell assay was 10 ng/mL using a concentration of 1.6 x 10(5) cells/well. Solid-state fermentation (SSF) and treatment with calcium compounds were used as cake detoxification processes. For SSF, Aspergillus niger was grown using a castor cake as a substrate, and this cake was analyzed after 24, 48, 72, and 96 h of SSF. Ricin was eliminated after 24 h of SSF treatment. The cake was treated with 4 or 8% Ca(OH)2 or CaO, and both the toxicity and the allergenic properties were entirely abolished. A by-product free of toxicity and allergens was obtained.
Assuntos
Alérgenos/efeitos dos fármacos , Aspergillus niger/crescimento & desenvolvimento , Compostos de Cálcio/farmacologia , Inativação Metabólica , Ricinus communis/efeitos dos fármacos , Albuminas 2S de Plantas/isolamento & purificação , Albuminas 2S de Plantas/toxicidade , Alérgenos/toxicidade , Animais , Aspergillus niger/efeitos dos fármacos , Ricinus communis/toxicidade , Morte Celular/efeitos dos fármacos , Degranulação Celular/efeitos dos fármacos , Chlorocebus aethiops , Ativação Enzimática , Fermentação , L-Lactato Desidrogenase/metabolismo , Mastócitos/efeitos dos fármacos , Ricina/isolamento & purificação , Ricina/toxicidade , Fatores de Tempo , Testes de Toxicidade , Células VeroRESUMO
This study evaluated Cd and Pb accumulation by castor bean (Ricinus communis cv. Guarany) plants grown in nutrient solution, aiming to assess the plant's ability and tolerance to grow in Cd- and Pb-contaminated solutions for phytoremediation purposes. The plants were grown in individual pots containing Hoagland and Arnon's nutrient solution with increasing concentrations of Cd and Pb. The production of root and shoot dry matter and their contents of Cd, Pb, Ca, Mg, Cu, Fe, Mn, and Zn were evaluated in order to calculate the translocation and bioaccumulation factors, as well as toxicity of Cd and Pb. Cadmium caused severe symptoms of phytotoxicity in the plant's root and shoot, but no adverse effect was observed for Pb. Castor bean is an appropriate plant to be used as indicator plant for Cd and tolerante for Pb in contaminated solution and it can be potentially used for phytoremediation of contaminated areas.
Assuntos
Cádmio/metabolismo , Chumbo/metabolismo , Ricinus communis/metabolismo , Poluentes do Solo/metabolismo , Biodegradação Ambiental , Biomassa , Cádmio/toxicidade , Ricinus communis/efeitos dos fármacos , Ricinus communis/crescimento & desenvolvimento , Relação Dose-Resposta a Droga , Chumbo/toxicidade , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Brotos de Planta/efeitos dos fármacos , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/metabolismo , Poluentes do Solo/toxicidadeRESUMO
Jasmonates are signaling molecules that play a key role in the regulation of metabolic processes, reproduction and defense against insects and pathogens. This study investigated the effects of methyl jasmonate on the protein pattern of Ricinus communis plants and the activity of guaiacol peroxidase, an antioxidant enzyme. Methyl jasmonate treatment caused a transient reduction in guaiacol peroxidase activity. A similar response was observed for the levels of 2-Cys peroxiredoxin protein. Moreover, the levels of the small and large chains of Rubisco were also reduced. The transient reduction of the levels and activity of antioxidant enzymes could account for the increase in the levels of H2O2, an important signaling molecule in plant defense.
Assuntos
Acetatos/farmacologia , Ciclopentanos/farmacologia , Peroxidases/metabolismo , Reguladores de Crescimento de Plantas/farmacologia , Ricinus communis/enzimologia , Sequência de Aminoácidos , Ricinus communis/efeitos dos fármacos , Oxilipinas , Fragmentos de Peptídeos , Peroxidase/efeitos dos fármacos , Peroxidase/metabolismo , Peroxidases/efeitos dos fármacos , Peroxirredoxinas , Proteínas de Plantas/efeitos dos fármacos , Proteínas de Plantas/isolamento & purificação , Proteínas de Plantas/metabolismo , Ribulose-Bifosfato Carboxilase/química , Ribulose-Bifosfato Carboxilase/metabolismo , Alinhamento de Sequência , Homologia de Sequência de AminoácidosRESUMO
Plants of Ricinus communis L. in the city of Porto Alegre, in southern Brazil, were exposed to urban traffic exhaust emissions for 5 months and compared with controls kept at a site essentially free of direct motor vehicle emissions. No symptomatic visible injuries were observed, but significant differences could be measured in growth, enzymatic activities of total peroxidase and nitrate reductase, chlorophyll content, leaf buffering capacity, and N contents in leaves. Additionally, these data were compared with results from fumigation experiments under controlled conditions. The study showed that some physiological parameters in R. communis L. plants could be used as an appropriate bioindicator system for urban traffic contamination, and therefore it is recommended that dose-response relationships should be developed.