RESUMO
NEP1 (necrosis- and ethylene-inducing peptide 1)-like proteins (NLPs) have been identified in a variety of taxonomically unrelated plant pathogens and share a common characteristic of inducing responses of plant defense and cell death in dicotyledonous plants. Even though some aspects of NLP action have been well characterized, nothing is known about the global range of modifications in proteome and metabolome of NLP-treated plant cells. Here, using both proteomic and metabolomic approaches we were able to identify the global molecular and biochemical changes in cells of Nicotiana benthamiana elicited by short-term treatment with MpNEP2, a NLP of Moniliophthora perniciosa, the basidiomycete responsible for the witches' broom disease on cocoa (Theobroma cacao L.). Approximately 100 protein spots were collected from 2-DE gels in each proteome, with one-third showing more than twofold differences in the expression values. Fifty-three such proteins were identified by mass spectrometry (MS)/MS and mapped into specific metabolic pathways and cellular processes. Most MpNEP2 upregulated proteins are involved in nucleotide-binding function and oxidoreductase activity, whereas the downregulated proteins are mostly involved in glycolysis, response to stress and protein folding. Thirty metabolites were detected by gas spectrometry (GC)/MS and semi-quantified, of which eleven showed significant differences between the treatments, including proline, alanine, myo-inositol, ethylene, threonine and hydroxylamine. The global changes described affect the reduction-oxidation reactions, ATP biosynthesis and key signaling molecules as calcium and hydrogen peroxide. These findings will help creating a broader understanding of NLP-mediated cell death signaling in plants.
Assuntos
Agaricales/fisiologia , Proteínas Fúngicas/fisiologia , Interações Hospedeiro-Parasita , Metaboloma/fisiologia , Nicotiana/metabolismo , Nicotiana/parasitologia , Células Cultivadas , Ontologia Genética , Anotação de Sequência Molecular , Doenças das Plantas/microbiologia , Proteínas de Plantas/fisiologia , Proteoma/fisiologia , Nicotiana/citologiaRESUMO
BACKGROUND: The hemibiotrophic fungus Moniliophthora perniciosa is the causal agent of Witches' broom, a disease of Theobroma cacao. The pathogen life cycle ends with the production of basidiocarps in dead tissues of the infected host. This structure generates millions of basidiospores that reinfect young tissues of the same or other plants. A deeper understanding of the mechanisms underlying the sexual phase of this fungus may help develop chemical, biological or genetic strategies to control the disease. RESULTS: Mycelium was morphologically analyzed prior to emergence of basidiomata by stereomicroscopy, light microscopy and scanning electron microscopy. The morphological changes in the mycelium before fructification show a pattern similar to other members of the order Agaricales. Changes and appearance of hyphae forming a surface layer by fusion were correlated with primordia emergence. The stages of hyphal nodules, aggregation, initial primordium and differentiated primordium were detected. The morphological analysis also allowed conclusions on morphogenetic aspects. To analyze the genes involved in basidiomata development, the expression of some selected EST genes from a non-normalized cDNA library, representative of the fruiting stage of M. perniciosa, was evaluated. A macroarray analysis was performed with 192 selected clones and hybridized with two distinct RNA pools extracted from mycelium in different phases of basidiomata formation. This analysis showed two groups of up and down-regulated genes in primordial phases of mycelia. Hydrophobin coding, glucose transporter, Rho-GEF, Rheb, extensin precursor and cytochrome p450 monooxygenase genes were grouped among the up-regulated. In the down-regulated group relevant genes clustered coding calmodulin, lanosterol 14 alpha demethylase and PIM1. In addition, 12 genes with more detailed expression profiles were analyzed by RT-qPCR. One aegerolysin gene had a peak of expression in mycelium with primordia and a second in basidiomata, confirming their distinctiveness. The number of transcripts of the gene for plerototolysin B increased in reddish-pink mycelium and indicated an activation of the initial basidiomata production even at this culturing stage. Expression of the glucose transporter gene increased in mycelium after the stress, coinciding with a decrease of adenylate cyclase gene transcription. This indicated that nutrient uptake can be an important signal to trigger fruiting in this fungus. CONCLUSION: The identification of genes with increased expression in this phase of the life cycle of M. perniciosa opens up new possibilities of controlling fungus spread as well as of genetic studies of biological processes that lead to basidiomycete fruiting. This is the first comparative morphologic study of the early development both in vivo and in vitro of M. perniciosa basidiomata and the first description of genes expressed at this stage of the fungal life cycle.
Assuntos
Agaricales/crescimento & desenvolvimento , Agaricales/genética , Perfilação da Expressão Gênica , Doenças das Plantas/microbiologia , Sequência de Aminoácidos , Cacau/microbiologia , Etiquetas de Sequências Expressas , Proteínas Fúngicas/genética , Regulação Fúngica da Expressão Gênica , Biblioteca Gênica , Genes Fúngicos , Genoma Fúngico , Proteínas Hemolisinas/genética , Dados de Sequência Molecular , Micélio/genética , Micélio/crescimento & desenvolvimento , Análise de Sequência com Séries de Oligonucleotídeos , RNA Fúngico/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Alinhamento de Sequência , Análise de Sequência de DNARESUMO
This paper deals with the traditional ichthyological knowledge of fishermens community from the city of Barra, which is located in the west region of Bahia State, Northeast Brazil. These fishermen develop their usual activities at the edges of São Francisco and Grande rivers. Fieldwork was carried out from January to June 2000. A total of 15 informants (ten male and five female) were consulted through open and semi-structured interviews, with the aim to record both the cognitive (ethnotaxonomy, reproduction, behaviour, food ecology, habitat) and cultural aspects (restrictions to the fish eating and their use as folk medicine) towards the local fish species. Eighteen fish specimens were usually collected and identified, and they are deposited at the Laboratory of Ichthyology of the Feira de Santana State University. Results show that Barras fishermen still hold an important theoretical and practical knowledge that should be taken into account in the management, conservation actions, and sustainable use of the local fishing resources. As noted, men-made ecological problems such as predatory fishing and the introduction of exotic species, have been already affecting fishermens ordinary life both from the city of Barra and surroundings.
No artigo discute-se o conhecimento ictiológico tradicional de uma comunidade pesqueira da cidade de Barra, localizada na região oeste do Estado da Bahia, nordeste do Brasil. Os pescadores de Barra desenvolvem suas atividades habituais às margens dos rios São Francisco e Grande. O trabalho de campo foi realizado no período de janeiro a junho de 2000. Foram consultados 15 informantes (10 homens e 5 mulheres) através de entrevistas livres e semi-estruturadas com o objetivo de registrar os aspectos cognitivos (etnotaxonomia, reprodução, comportamento, ecologia trófica, hábitat) e culturais (restrições ao consumo de peixes e usos na medicina popular) relacionados com as espécies de peixes locais. Dezoito espécies foram coletadas, identificadas e encontram-se depositadas no Laboratório de Ictiologia da Universidade Estadual de Feira de Santana. Os resultados revelam que os pescadores ainda possuem conhecimentos teóricos e práticos importantes que devem ser considerados em estudos de manejo, conservação e uso sustentável dos recursos pesqueiros. Problemas ecológicos de origem antrópica, tais como pesca predatória e introdução de espécies exóticas, vêm afetando o modo de vida dos pescadores tradicionais, tanto os da cidade de Barra como os das áreas adjacentes.
RESUMO
This paper deals with the traditional ichthyological knowledge of fishermens community from the city of Barra, which is located in the west region of Bahia State, Northeast Brazil. These fishermen develop their usual activities at the edges of São Francisco and Grande rivers. Fieldwork was carried out from January to June 2000. A total of 15 informants (ten male and five female) were consulted through open and semi-structured interviews, with the aim to record both the cognitive (ethnotaxonomy, reproduction, behaviour, food ecology, habitat) and cultural aspects (restrictions to the fish eating and their use as folk medicine) towards the local fish species. Eighteen fish specimens were usually collected and identified, and they are deposited at the Laboratory of Ichthyology of the Feira de Santana State University. Results show that Barras fishermen still hold an important theoretical and practical knowledge that should be taken into account in the management, conservation actions, and sustainable use of the local fishing resources. As noted, men-made ecological problems such as predatory fishing and the introduction of exotic species, have been already affecting fishermens ordinary life both from the city of Barra and surroundings.
No artigo discute-se o conhecimento ictiológico tradicional de uma comunidade pesqueira da cidade de Barra, localizada na região oeste do Estado da Bahia, nordeste do Brasil. Os pescadores de Barra desenvolvem suas atividades habituais às margens dos rios São Francisco e Grande. O trabalho de campo foi realizado no período de janeiro a junho de 2000. Foram consultados 15 informantes (10 homens e 5 mulheres) através de entrevistas livres e semi-estruturadas com o objetivo de registrar os aspectos cognitivos (etnotaxonomia, reprodução, comportamento, ecologia trófica, hábitat) e culturais (restrições ao consumo de peixes e usos na medicina popular) relacionados com as espécies de peixes locais. Dezoito espécies foram coletadas, identificadas e encontram-se depositadas no Laboratório de Ictiologia da Universidade Estadual de Feira de Santana. Os resultados revelam que os pescadores ainda possuem conhecimentos teóricos e práticos importantes que devem ser considerados em estudos de manejo, conservação e uso sustentável dos recursos pesqueiros. Problemas ecológicos de origem antrópica, tais como pesca predatória e introdução de espécies exóticas, vêm afetando o modo de vida dos pescadores tradicionais, tanto os da cidade de Barra como os das áreas adjacentes.