RESUMO
Pfaffia glomerata is a medically important species because it produces the phytoecdysteroid 20-hydroxyecdysone (20-E). However, there has been no ready-to-use transcriptome data available in the literature for this plant. Here, we present de novo transcriptome sequencing of RNA from P. glomerata in order to investigate the 20-E production as well as to understand the biochemical pathway of secondary metabolites in this non-model species. We then analyze the effect of photoautotrophy on the production of 20-E genes phylogenetically identified followed by expression analysis. For this, total messenger RNA (mRNA) from leaves, stems, roots, and flowers was used to construct indexed mRNA libraries. Based on the similarity searches against plant non-redundant protein database, gene ontology, and eukaryotic orthologous groups, 164,439 transcripts were annotated. In addition, the effect of photoautotrophy in two genes putatively involved in the 20-E synthesis pathway was analyzed. The Phantom gene (CYP76C), a precursor of the route, showed increased expression in P. glomerata plants cultured under photoautotrophic conditions. This was accompanied by increased production of this metabolite indicating a putative involvement in 20-E synthesis. This work reveals that several genes in the P. glomerata transcriptome are related to secondary metabolism and stresses, that genes of the P450 family participate in the 20-E biosynthesis route, and that plants cultured under photoautotrophic conditions promote an upregulated Phantom gene and enhance the productivity of 20-E. The data will be used for future investigations of the 20-E synthesis pathway in P. glomerata while offering a better understanding of the metabolism of the species.
Assuntos
Amaranthaceae/genética , Processos Autotróficos , Sistema Enzimático do Citocromo P-450/genética , Ecdisterona/biossíntese , Genes de Plantas , Família Multigênica , Processos Fototróficos , Transcriptoma/genética , Processos Autotróficos/genética , Vias Biossintéticas/genética , Regulação da Expressão Gênica de Plantas , Ontologia Genética , Anotação de Sequência Molecular , Fases de Leitura Aberta/genética , Processos Fototróficos/genética , Filogenia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reprodutibilidade dos Testes , Análise de Sequência de RNARESUMO
In vitro tests conducted with extracts rich in tannins have identified several biological activities of this class of substance. Thus, this paper intends to evaluate the antibacterial activity of tannin-rich fraction obtained from leaf extracts of Anacardium humile A.St.-Hil. Extracts of A. humile leaves in 70% acetone were semi-purified with ethyl acetate and butanol. We quantified the total tannins of the semi-purified fractions, of the crude extract and of aqueous residues and then performed tests of the antibacterial activity of the tannins against Staphylococcus aureus ATCC 6538, Pseudomonas aeruginosa ATCC 27853 and Enterococcus faecalis ATCC 29212. All positive extracts underwent tannin isolation using a Sephadex LH-20 column. The tannins isolated from the samples were quantified and tested for the minimal inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC). The tannins from crude extracts, semi-purifications and residues showed inhibition of S. aureus growth with MIC=500 g mL-1. All tannin fractions showed MIC against all strains and MBC, except against E. faecalis. The tannin fractions from Anacardium humile have antibacterial activity against Staphylococcus aureus, Pseudomononas aeruginosa and Enterococcus faecalis and, therefore, may be promising for future synthesis of new antibacterial agents.
Testes in vitro realizados com extratos ricos em taninos têm identificado muitas atividades biológicas dessa classe de substâncias. Nesse contexto, esse artigo propõe a avaliação da atividade antibacteriana de frações tânicas, obtidas de extratos de folhas de Anacardium humile A.St.-Hil. Extratos de A. humile em acetona 70% foram particionados com acetato de etila e butanol. Foram quantificados taninos totais das frações particionadas, do extrato bruto e dos resíduos aquosos, e foi realizado teste de atividade antibacteriana dos taninos contra Staphylococcus aureus ATCC 6538, Pseudomonas aeruginosa ATCC 27853 e Enterococcus faecalis ATCC 29212. Todos os extratos positivos foram submetidos ao isolamento de taninos, utilizando-se coluna de Sephadex LH-20. Os taninos isolados das amostras foram quantificados e testados sua concentração inibitória mínima (CIM) e concentração bactericida mínima (CBM). Os taninos do extrato bruto, partições e resíduos apresentaram inibição do crescimento de S.aureus com CIM =500 g mL-1. As frações tânicas apresentaram CIM contra todas as cepas e CBM, exceto contra E. faecalis. As frações tânicas de Anacardium humile possuem atividade antibacteriana contra Staphylococcus aureus, Pseudomononas aeruginosa e Enterococcus faecalis e, portanto, podem ser promissoras em sínteses futuras de novos agentes antimicrobianos.
