RESUMO
Castor bean (Ricinus communis L.) can withstand long periods of water deficit and high temperatures, and therefore has been recognized as a drought-resistant plant species, allowing the study of gene networks involved in drought response and tolerance. The identification of genes networks related to drought response in this plant may yield important information in the characterization of molecular mechanisms correlating changes in the gene expression with the physiological adaptation processes. In this context, gene families related to abscisic acid (ABA) signaling play a crucial role in developmental and environmental adaptation processes of plants to drought stress. However, the families that function as the core components of ABA signaling, as well as genes networks related to drought response, are not well understood in castor bean. In this study 7 RcPYL, 63 RcPP2C, and 6 RcSnRK2 genes were identified in castor bean genome, which was further supported by chromosomal distribution, gene structure, evolutionary relationships, and conserved motif analyses. The castor bean general expression profile was investigated by RNAseq in root and leaf tissues in response to drought stress. These analyses allowed the identification of genes differentially expressed, including genes from the ABA signaling core, genes related to photosynthesis, cell wall, energy transduction, antioxidant response, and transcription factors. These analyses provide new insights into the core components of ABA signaling in castor bean, allow the identification of several molecular responses associated with the high physiological adaptation of castor bean to drought stress, and contribute to the identification of candidate genes for genetic improvement.
Assuntos
Ricinus communis , Ricinus communis/genética , Ricinus communis/metabolismo , Ricinus/genética , Ricinus/metabolismo , Redes Reguladoras de Genes , Secas , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Transcriptoma , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Ácido Abscísico/metabolismoRESUMO
Ricin is a highly toxic ribosome-inactivating lectin occurring in the seeds of castor bean (Ricinus communis L.). Castor bean grows throughout tropical and sub-tropical regions and is a very important crop due to its high seed content of ricinoleic acid, an unusual fatty acid, which has several industrial applications. However, due to the presence of the toxin, castor bean can cause death after the exposure of animals to low doses of ricin through skin contact, injection, inhalation or oral routes. Aiming to generate a detoxified genotype, we explored the RNAi concept in order to silence the ricin coding genes in the endosperm of castor bean seeds. Results indicated that ricin genes were effectively silenced in genetically modified (GM) plants, and ricin proteins were not detected by ELISA. Hemagglutination activity was not observed with proteins isolated from GM seeds. In addition, we demonstrated that seed proteins from GM plants were not toxic to rat intestine epithelial cells or to Swiss Webster mice. After oil extraction, bio-detoxified castor bean cake, which is very rich in valuable proteins, can be used for animal feeding. Gene silencing would make castor bean cultivation safer for farmers, industrial workers and society.
Assuntos
Plantas Geneticamente Modificadas , Ricina/genética , Ricina/metabolismo , Ricina/toxicidade , Ricinus communis , Sementes , Animais , Ricinus communis/genética , Ricinus communis/metabolismo , Camundongos , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Ratos , Sementes/genética , Sementes/metabolismoRESUMO
Biomonitoring of air quality using living organisms is a very interesting approach to environmental impact assessment. Organisms with a vast distribution, such as plants, are widely used for these purposes. The castor bean (Ricinus communis L.) is an oleaginous plant that can potentially be used as a bioindicator plant owing to its rapid growth and large leaves, which have a wide surface area of contact with the air and the pollutants therein. This study investigated the the bioindicator potential of the castor bean by performing several tests. We observed statistically significant differences in the concentrations of chlorophyll a and b in the leaves of plants in polluted areas compared to that in the control group plants, which were located in a pollution-free area. Leaves of plants in the former group had higher peroxidase activity and showed a greater buffering ability than those of plants in the control group. The pKa values obtained via buffering capacity tests, revealed the presence of aminoazobenzene (an industrial dye) in leaves of R. communis. Genotoxicity was evaluated through the comet assay technique and revealed that other than some differences in DNA fragmentation, there is no statistically significant difference in this parameter between places analyzed. Our data indicate that R. communis can be a highly useful biological indicator. Further, we hypothesized that the castor bean can be a potential candidate for phytoremediation owing its physiological buffering capacity when exposed to substantial pollution.
Assuntos
Ricinus communis/metabolismo , Biodegradação Ambiental , Ensaio Cometa , Fotossíntese/fisiologiaRESUMO
In this work, a biorefinery system including castor bean seeds and microalgae is used as a case study to evaluate the integration of second and third generation biorefineries. A biorefinery concept was applied for the combined production of polyol, ethylene-glycol, omega-3 acid, biodiesel, methanol and heat and power from castor bean and microalgae. Castor bean cake and microalgae paste were used to feed a biomass-fired system (BIGCC), where part of CO2 produced in flue gas is captured and employed as substrate for microalgae growth. To evaluate the performance of this biorefinery concept three scenarios based on different levels of mass and energy integration were modeled and assessed from techno-economic and environmental points of view. The scenario with the best economic and environmental performances was the one including full mass integration, full heat integration, and cogeneration scheme.
Assuntos
Biocombustíveis , Microalgas , Ricinus communis , Biomassa , Reatores Biológicos , Ricinus communis/química , Ricinus communis/metabolismo , Microalgas/química , Microalgas/metabolismoRESUMO
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
Bioenergy production combined with phytoremediation has been suggested to help in solving two critical world problems: the gradual reduction of fossil fuels and soil contamination. The aim of this research was to investigate the potential for the use of Ricinus communis L. (castor oil plant) as an energy crop and plant species to remediate metal-polluted sites. This study was performed in mine tailings containing high concentrations of Cu, Zn, Mn, Pb and Cd. Physico-chemical characterization, total, DTPA-extractable and water-soluble metals in rhizospheric tailings heap samples were carried. Metal concentrations in plant tissues and translocation factors (TFs) were also determined. The Ricinus seed-oil content was high between 41 and 64%, seeds from San Francisco site 6 had the highest oil content, while these from site 7 had the lowest. No trend between oil yield vs seed origin site was observed. Seed-oil content was negatively correlated with root concentration of Cu, Zn, Pb and Cd, but no correlation was observed with the extractable-metals. According to its shoot metal concentrations and TFs, castor bean is not a metal accumulator plant. This primary colonizing plant is well suited to cope with the local toxic conditions and can be useful for the stabilization of these residues, and for then decreasing metal bioavailability, dispersion and human health risks on these barren tailings heaps and in the surrounding area. Our work is the first report regarding combined oil production and a phytostabilization role for Ricinus plants in metal mine tailings and may give a new value to suitable metal-polluted areas.
Assuntos
Biodegradação Ambiental , Biocombustíveis/análise , Óleo de Rícino/biossíntese , Ricinus communis/metabolismo , Ricinus communis/microbiologia , Resíduos Industriais/análise , Metais Pesados/análise , Mineração , Micorrizas/fisiologia , Poluentes do Solo/análiseRESUMO
Recent years have seen an increase in the forensic interest associated with the poison ricin, which is extracted from the seeds of the Ricinus communis plant. Both light element (C, N, O, and H) and strontium (Sr) isotope ratios have previously been used to associate organic material with geographic regions of origin. We present a Bayesian integration methodology that can more accurately predict the region of origin for a castor bean than individual models developed independently for light element stable isotopes or Sr isotope ratios. Our results demonstrate a clear improvement in the ability to correctly classify regions based on the integrated model with a class accuracy of 60.9 ± 2.1% versus 55.9 ± 2.1% and 40.2 ± 1.8% for the light element and strontium (Sr) isotope ratios, respectively. In addition, we show graphically the strengths and weaknesses of each dataset in respect to class prediction and how the integration of these datasets strengthens the overall model.
Assuntos
Geografia , Marcação por Isótopo/métodos , Ricinus communis/metabolismo , Área Sob a Curva , Teorema de Bayes , Brasil , China , Índia , Isótopos , Modelos Biológicos , Curva ROC , Tamanho da Amostra , Isótopos de Estrôncio , Estados UnidosRESUMO
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
BACKGROUND: The allergenicity of Ricinus communis L. (castor bean, Euphorbiaceae) is associated with components of its seeds and pollen. Castor bean allergy has been described not only in laboratory workers, but also in personnel working in oil processing mills, fertilizer retail, the upholstery industry and other industrial fields. In the present study, we describe the critical amino acids in the IgE-binding epitopes in Ric c 1 and Ric c 3, two major allergens of R. communis. In addition, we also investigate the cross-reactivity between castor bean and some air and food allergen extracts commonly used in allergy diagnosis. METHODOLOGY/PRINCIPAL FINDINGS: The IgE reactivity of human sera from atopic patients was screened by immune-dot blot against castor bean allergens. Allergenic activity was evaluated in vitro using a rat mast cell activation assay and by ELISA. Cross-reactivity was observed between castor bean allergens and extracts from shrimp, fish, gluten, wheat, soybean, peanut, corn, house dust, tobacco and airborne fungal allergens. We observed that treatment of rat and human sera (from atopic patients) with glutamic acid reduced the IgE-epitope interaction. CONCLUSIONS/SIGNIFICANCE: The identification of glutamic acid residues with critical roles in IgE-binding to Ric c 3 and Ric c 1 support the potential use of free amino acids in allergy treatment.
Assuntos
Alérgenos/imunologia , Epitopos/imunologia , Ácido Glutâmico/farmacologia , Imunoglobulina E/efeitos dos fármacos , Imunoglobulina E/imunologia , Proteínas de Plantas/imunologia , Ricinus communis/imunologia , Animais , Ricinus communis/metabolismo , Células Cultivadas , Cromatografia de Afinidade , Humanos , Proteínas de Plantas/metabolismo , RatosRESUMO
The activity of ß-glucosidase (ßG), total cellulase (FPase) and endoglucanase (CMCase), produced by Aspergillus japonicus URM5620, was studied on solid-state fermentation using castor bean meal as substrate. The effect of the substrate amount, initial moisture, pH, and temperature on cellulase production was studied using a full factorial design (2(4)). The maximum ßG, FPase, and CMCase activity was 88.3, 953.4, and 191.6 U/g dry substrate, respectively. The best enzyme activities for all three enzymes were obtained at the same conditions with 5.0 g of substrate, initial moisture 15% at 25 °C and pH 6.0 with 120 h of fermentation. The optimum activity for FPase and CMCase was found at pH 3.0 at an optimum temperature of 50 °C for FPase and of 55 °C for CMCase. The cellulases were stable in the range of pH 3.0-10.0 at 50 °C temperature. The enzyme production optimization demonstrated clearly the impact of the process parameters on the yield of the cellulolytic enzymes.
Assuntos
Aspergillus/enzimologia , Celulase/biossíntese , Microbiologia Industrial/métodos , Ricinus communis/metabolismo , beta-Glucosidase/biossíntese , Algoritmos , Fermentação , Concentração de Íons de Hidrogênio , Cinética , Temperatura , Água/metabolismoRESUMO
The major Ricinus communis allergens are the 2S albumins, Ric c 1 and Ric c 3. These proteins contain a trypsin/α-amylase inhibitor family domain, suggesting that they have a role in insect resistance. In this study, we verified that Ric c 1 and Ric c 3 inhibited the α-amylase activity of Callosobruchus maculatus, Zabrotes subfasciatus, and Tenebrio molitor (TMA) larvae as well as mammalian α-amylase. The toxicity of 2S albumin was determined through its incorporation in C. maculatus larvae as part of an artificial diet. Bioassays revealed that 2S albumin reduced larval growth by 20%. We also analyzed the tridimensional structures of Ric c 1 and Ric c 3 by (a) constructing a comparative model of Ric c 1 based on Ric c 3 NMR structure and (b) constructing the theoretical structure of the Ric c 1-TMA and Ric c 3-TMA complexes. Our biological and theoretical results revealed that Ric c 1 and Ric c 3 are a new class of α-amylase inhibitors. They could potentially be used to help design inhibitors that would be useful in diverse fields, ranging from diabetes treatment to crop protection.
Assuntos
Albuminas 2S de Plantas/química , Antígenos de Plantas/química , Besouros/enzimologia , Inibidores Enzimáticos/química , Proteínas de Insetos/antagonistas & inibidores , Ricinus communis/química , alfa-Amilases/antagonistas & inibidores , Albuminas 2S de Plantas/metabolismo , Albuminas 2S de Plantas/farmacologia , Sequência de Aminoácidos , Animais , Antígenos de Plantas/metabolismo , Antígenos de Plantas/farmacologia , Ricinus communis/metabolismo , Besouros/química , Inibidores Enzimáticos/metabolismo , Inibidores Enzimáticos/farmacologia , Proteínas de Insetos/química , Proteínas de Insetos/metabolismo , Cinética , Dados de Sequência Molecular , Sementes/química , Sementes/metabolismo , Alinhamento de Sequência , alfa-Amilases/química , alfa-Amilases/metabolismoRESUMO
One relevant limitation hindering the industrial application of microbial lipases has been attributed to their production cost, which is determined by the production yield, enzyme stability among other. The objective of this work was to evaluate the concentration and immobilization of lipase extracts from Penicillium brevicompactum obtained by solid-state fermentation of babassu cake and castor bean cake. The precipitation with ammonium sulfate 60% of saturation of crude extract obtained with babassu cake as raw material showed an enhancement in hydrolytic and esterification activities from 31.82 to 227.57 U/g and from 170.92 to 207.40 U/g, respectively. Concentrated lipase extracts showed preference to medium-chain triglycerides and fatty acids. It is shown that the enzyme activity is maintained during storage at low temperatures (4 and -10°C) for up to 30 days. Higher esterification activities were achieved when the lipase extract was immobilized in sodium alginate and activated coal.
Assuntos
Arecaceae/metabolismo , Fermentação , Proteínas Fúngicas/química , Lipase/química , Penicillium/enzimologia , Ricinus communis/metabolismo , Arecaceae/microbiologia , Ricinus communis/microbiologia , Estabilidade Enzimática , Enzimas Imobilizadas/química , Enzimas Imobilizadas/isolamento & purificação , Enzimas Imobilizadas/metabolismo , Proteínas Fúngicas/isolamento & purificação , Proteínas Fúngicas/metabolismo , Lipase/isolamento & purificação , Lipase/metabolismo , Penicillium/química , Penicillium/metabolismoRESUMO
In countries with a strong agricultural base, such as Brazil, the generation of solid residues is very high. In some cases, these wastes present no utility due to their toxic and allergenic compounds, and so are an environmental concern. The castor bean (Ricinus communis) is a promising candidate for biodiesel production. From the biodiesel production process developed in the Petrobras Research Center using castor bean seeds, a toxic and alkaline waste is produced. The use of agroindustrial wastes in solid-state fermentation (SSF) is a very interesting alternative for obtaining enzymes at low cost. Therefore, in this work, castor bean waste was used, without any treatment, as a culture medium for fungal growth and lipase production. The fungus Penicillium simplicissimum was able to grow and produce an enzyme in this waste. In order to maximize the enzyme production, two sequential designs-Plackett-Burman (variable screening) followed by central composite rotatable design (CCRD)-were carried out, attaining a considerable increase in lipase production, reaching an activity of 155.0 U/g after 96 h of fermentation. The use of experimental design strategy was efficient, leading to an increase of 340% in the lipase production. Zymography showed the presence of different lipases in the crude extract. The partial characterization of such extract showed the occurrence of two lipase pools with distinct characteristics of pH and temperature of action: one group with optimal action at pH 6.5 and 45°C and another one at pH 9.0 and 25°C. These results demonstrate how to add value to a toxic and worthless residue through the production of lipases with distinct characteristics. This pool of enzymes, produced through a low cost methodology, can be applied in different areas of biotechnology.
Assuntos
Biocombustíveis/microbiologia , Substâncias Perigosas/metabolismo , Lipase/metabolismo , Penicillium/enzimologia , Ricinus communis/metabolismo , Resíduos , Biocombustíveis/economia , Biotecnologia , Brasil , Indústria Química , Meios de Cultura/química , Fermentação , Substâncias Perigosas/toxicidade , Concentração de Íons de Hidrogênio , Penicillium/crescimento & desenvolvimento , Eliminação de Resíduos/métodos , TemperaturaRESUMO
Phytoextraction is a remediation technique that consists in using plants to remove contaminants from soils and water. This study evaluated arsenic (As) accumulation in Castor bean (Ricinus communis cv. Guarany) grown in nutrient solution in order to assess its phytoextraction ability. Castor bean plants were grown under greenhouse conditions in pots containing a nutrient solution amended with increasing doses of As (0, 10, 50, 100, 250, 500 and 5000 microg L(-1)) in a completely randomized design with four replications. Shoot and roots dry matter production as well as arsenic and nutrient tissue concentrations were measured at the end of the experiment. The results showed that increasing As concentration in nutrient solution caused a decrease in shoot and root biomass but did not result in severe toxicity symptoms in castor bean growing under a range of As concentration from 0 to 5000 microg L(-1). The As doses tested did not affect the accumulation of nutrients by castor bean. Although castor bean did not pose characteristics of a plant suitable for commercial phytoextraction, it could be useful for revegetation of As-contaminated areas while providing an additional income by oil production.