RESUMO
BACKGROUND: New strategies are needed to combat multidrug-resistant bacteria. The restriction of iron uptake by bacteria is a promising way to inhibit their growth. We aimed to suppress the growth of Vibrio bacterial species by inhibiting their ferric ion-binding protein (FbpA) using food components. METHODS: Twenty spices were selected for the screening of FbpA inhibitors. The candidate was applied to antibacterial tests, and the mechanism was further studied. RESULTS: An active compound, rosmarinic acid (RA), was screened out. RA binds competitively and more tightly than Fe3+ to VmFbpA, the FbpA from V. metschnikovii, with apparent KD values of 8 µM vs. 17 µM. Moreover, RA can inhibit the growth of V. metschnikovii to one-third of the control at 1000 µM. Interestingly, sodium citrate (SC) enhances the growth inhibition effect of RA, although SC only does not inhibit the growth. The combination of RA/SC completely inhibits the growth of not only V. metschnikovii at 100/100 µM but also the vibriosis-causative pathogens V. vulnificus and V. parahaemolyticus, at 100/100 and 1000/100 µM, respectively. However, RA/SC does not affect the growth of Escherichia coli. CONCLUSIONS: RA/SC is a potential bacteriostatic agent against Vibrio species while causing little damage to indigenous gastrointestinal bacteria.
Assuntos
Cinamatos/farmacologia , Depsídeos/farmacologia , Ferro/metabolismo , Citrato de Sódio/farmacologia , Vibrio parahaemolyticus/efeitos dos fármacos , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Sítios de Ligação , Cinamatos/química , Cinamatos/metabolismo , Depsídeos/química , Depsídeos/metabolismo , Sinergismo Farmacológico , Proteínas de Ligação ao Ferro/química , Proteínas de Ligação ao Ferro/metabolismo , Simulação de Acoplamento Molecular , Extratos Vegetais/química , Ligação Proteica , Vibrio parahaemolyticus/metabolismo , Ácido RosmarínicoRESUMO
Magnesium (Mg) is an essential macronutrient, functioning as both a cofactor of many enzymes and as a component of Chl. Mg is abundant in plants; however, further investigation of the Mg transporters involved in Mg uptake and distribution is needed. Here, we isolated an Arabidopsis thaliana mutant sensitive to high calcium (Ca) conditions without Mg supplementation. The causal gene of the mutant encodes MRS2-4, an Mg transporter.MRS2-4 single mutants exhibited growth defects under low Mg conditions, whereas an MRS2-4 and MRS2-7 double mutant exhibited growth defects even under normal Mg concentrations. Under normal Mg conditions, the Mg concentration of the MRS2-4 mutant was lower than that of the wild type. The transcriptome profiles of mrs2-4-1 mutants under normal conditions were similar to those of wild-type plants grown under low Mg conditions. In addition, both mrs2-4 and mrs2-7 mutants were sensitive to high levels of Mg. These results indicate that both MRS2-4 and MRS2-7 are essential for Mg homeostasis, even under normal and high Mg conditions. MRS2-4-green fluorescent protein (GFP) was mainly detected in the endoplasmic reticulum. These results indicate that these two MRS2 transporter genes are essential for the ability to adapt to a wide range of environmental Mg concentrations.
Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Proteínas de Transporte de Cátions/metabolismo , Magnésio/metabolismo , Adaptação Fisiológica/genética , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/genética , Proteínas de Transporte de Cátions/genética , Retículo Endoplasmático/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Homeostase , Magnésio/farmacocinética , Raízes de Plantas/metabolismoRESUMO
Manganese (Mn) is an essential micronutrient for plants, but is toxic when present in excess. The rice plant (Oryza sativa L.) accumulates high concentrations of Mn in the aerial parts; however, the molecular basis for Mn tolerance is poorly understood. In the present study, genes encoding Mn tolerance were screened for by expressing cDNAs of genes from rice shoots in Saccharomyces cerevisiae. A gene encoding a cation diffusion facilitator (CDF) family member, OsMTP8.1, was isolated, and its expression was found to enhance Mn accumulation and tolerance in S. cerevisiae. In plants, OsMTP8.1 and its transcript were mainly detected in shoots. High or low supply of Mn moderately induced an increase or decrease in the accumulation of OsMTP8.1, respectively. OsMTP8.1 was detected in all cells of leaf blades through immunohistochemistry. OsMTP8.1 fused to green fluorescent protein was localized to the tonoplast. Disruption of OsMTP8.1 resulted in decreased chlorophyll levels, growth inhibition in the presence of high concentrations of Mn, and decreased accumulation of Mn in shoots and roots. However, there was no difference in the accumulation of other metals, including Zn, Cu, Fe, Mg, Ca, and K. These results suggest that OsMTP8.1 is an Mn-specific transporter that sequesters Mn into vacuoles in rice and is required for Mn tolerance in shoots.
Assuntos
Adaptação Fisiológica/efeitos dos fármacos , Manganês/toxicidade , Oryza/fisiologia , Proteínas de Plantas/metabolismo , Sequência de Aminoácidos , Cátions , DNA Complementar/genética , DNA Complementar/isolamento & purificação , Difusão , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Técnicas de Silenciamento de Genes , Dados de Sequência Molecular , Mutação/genética , Oryza/efeitos dos fármacos , Oryza/genética , Fenótipo , Proteínas de Plantas/química , Proteínas de Plantas/genética , Transporte Proteico/efeitos dos fármacos , Saccharomyces cerevisiae/efeitos dos fármacos , Análise de Sequência de Proteína , Frações Subcelulares/efeitos dos fármacos , Frações Subcelulares/metabolismoRESUMO
Understanding of the molecular mechanisms of boron (B) transport has been greatly advanced in the last decade. BOR1, the first B transporter in living systems, was identified by forward genetics using Arabidopsis mutants. Genes similar to BOR1 have been reported to share different physiological roles in plants. NIPS;1, a member of aquaporins in Arabidopsis, was then identified as a boric acid channel gene responsible for the B uptake into roots. NIP6;1, the most similar gene to NIPS;1, encodes a B channel essential for B distribution to young leaves. In the present chapter, recent advancement of the understanding of molecular mechanisms of B transport and roles of NIP genes are discussed.