RESUMO
Pairs polyphylla var. yunnanensis (Paris L.) is a valuable medicinal plant used in traditional Chinese medicine. The market demand for P. polyphylla has increased over time, but it has slow growth and a low natural propagation rate. Endophytic bacteria are bioactive microorganisms that form a mutualistic relationship with host plants in long-term coordinated evolution, and they can promote the growth and accumulation of effective components in host plants. The aims of this study were to identify endophytic bacteria of P. polyphylla and to characterize their properties in promoting plant growth. A total of 10 endophytic bacteria were isolated from rhizomes of P. polyphylla. The isolated endophytes exhibited a variable capacity for indole acetic acid production, phosphate solubilization and nitrogen fixation. To investigate the effects of the endophytes on plant growth, four endophyte strains, G5, J2, G20, and Y2, were selected to compare their ability to promote plant growth. The results indicated that microbial endophytes isolated from P. polyphylla rhizomes play a vital role in improving P. polyphylla plant growth and could be used as inoculants to establish a sustainable crop production system.
Assuntos
Fenômenos Fisiológicos Bacterianos , Endófitos/fisiologia , Melanthiaceae/crescimento & desenvolvimento , Melanthiaceae/microbiologia , Desenvolvimento Vegetal , Rizoma/microbiologia , DNA Bacteriano , Interações entre Hospedeiro e Microrganismos , Ácidos Indolacéticos/metabolismo , Plantas Medicinais/crescimento & desenvolvimento , Plantas Medicinais/microbiologia , SimbioseRESUMO
Penctrimertone (1), a novel citrinin dimer bearing a 6/6/6/6 tetracyclic ring scaffold, along with two known compounds xerucitrinic acid A (2) and citrinin (3) were isolated from the endophytic fungus Penicillium sp. T2-11. Their structures were unequivocally established by a comprehensive interpretation of the spectroscopic data, with the stereochemistry for 1 was defined by a combination of TDDFT-ECD calculations and the DP4+ probability analysis based on NMR chemical shift calculations. Bioassays revealed that compound 1 exhibited noticeable antimicrobial activities and moderate cytotoxicity. A plausible biosynthetic pathway of 1 was also proposed.
Assuntos
Antibacterianos/farmacologia , Antineoplásicos/farmacologia , Citrinina/farmacologia , Gastrodia/microbiologia , Penicillium/química , Antibacterianos/isolamento & purificação , Antineoplásicos/isolamento & purificação , Produtos Biológicos/isolamento & purificação , Produtos Biológicos/farmacologia , Linhagem Celular Tumoral , Queixo , Citrinina/isolamento & purificação , Endófitos/química , Humanos , Estrutura Molecular , Rizoma/microbiologiaRESUMO
Protease mediated proteolysis has been widely implicated in virulence of necrotrophic fungal pathogens. This is counteracted in plants by evolving new and effective antimicrobial peptides (AMP) that constitute important components of innate immune system. Peptide extraction from rhizome of Zingiber zerumbet was optimized using ammonium sulphate (50-80% w/v) and acetone (60 and 100% v/v) with maximal protein recovery of 1.2 ± 0.4 mg/g obtained using 100% acetone. Evaluation of inhibitory potential of Z. zerumbet rhizome protein extract to prominent hydrolases of necrotrophic Pythium myriotylum revealed maximal inhibition of proteases (75.8%) compared to other hydrolytic enzymes. Protein was purified by Sephacryl S200HR resin resulting in twofold purification and protease inhibition of 84.4%. Non-reducing polyacrylamide gel electrophoresis (PAGE) of the fractions yielded two bands of 75 kDa and 25 kDa molecular size. Peptide mass fingerprint of the protein bands using matrix assisted laser desorption/ionization (MALDI)-time of flight (TOF) mass spectroscopy (MS) and subsequent MASCOT searches revealed peptide match to methylesterase from Arabidopsis thaliana (15%) and to hypothetical protein from Oryza sativa (98%) respectively. Further centrifugal filter purification using Amicon Ultra (10,000 MW cut-off) filter, yielded a prominent band of 25 kDa size. Concentration dependent inhibition of zoospore viability by Z. zerumbet AMP designated as ZzAMP was observed with maximal inhibition of 89.5% at 4 µg protein and an IC50 value of 0.59 µg. Studies are of particular relevance in the context of identifying the molecules involved in imparting below ground defense in Z. zerumbet as well in development of AMPs as potential candidate molecules for control of necrotrophic pathogens of agricultural relevance.
Assuntos
Antibacterianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/farmacologia , Peptídeo Hidrolases/efeitos dos fármacos , Extratos Vegetais/farmacologia , Pythium/efeitos dos fármacos , Rizoma/microbiologia , Zingiberaceae/microbiologia , Antibacterianos/química , Peptídeos Catiônicos Antimicrobianos/química , Arabidopsis , Inibidores Enzimáticos , Fungos/efeitos dos fármacos , Oryza , Peptídeos/farmacologia , Extratos Vegetais/química , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Zingiberaceae/crescimento & desenvolvimentoRESUMO
An emerging stress of nanomaterials in soil and water is of great concern as it limits crop productivity and affects humans as well. Therefore, it is required to manage this problem. Silicon and plant growth promoting rhizobacteria has gained the engaging role in agriculture as (bio-)fertilizers. However, their role against silver nanoparticles (AgNPs) is still not known. Hence, present study was envisaged to investigate role of Si, PGPR and phytohormone indole acetic acid (IAA) in regulating AgNP stress in Brassica juncea seedlings. The study highlighted the impact of various treatments with respect to overproduction of reactive oxygen species, signaling molecule nitric oxide, oxidative markers like antioxidant enzymes and nonenzymatic components of ascorbate-glutathione pathway. Interestingly, silicon when present with AgNPs enhanced toxicity by reducing growth and mechanistic properties of B. juncea. Moreover, the results highlight the role of PGPR and IAA towards reduction in toxicity by promoting the plant growth under stressed conditions. Treatments AgNP + Si + PGPR/IAA were observed to significantly reduce the stress and enhance plant growth against treatment AgNPs alone. This reversal in toxicity by PGPR and IAA along with Si suggests the idea to formulate and utilize their combination as biofertilizers for eradicating the stress in near future.
Assuntos
Bacillus thuringiensis , Nanopartículas Metálicas/toxicidade , Mostardeira/efeitos dos fármacos , Óxido Nítrico/metabolismo , Rizoma/microbiologia , Silício/toxicidade , Prata/toxicidade , Ácido Ascórbico/metabolismo , Glutationa/metabolismo , Ácidos Indolacéticos/farmacologia , Mostardeira/crescimento & desenvolvimento , Mostardeira/microbiologiaRESUMO
Peniterester (1), a new tricyclic sesquiterpene, together with 6 known compounds (2-7) were isolated from the secondary metabolites of an artificial mutant Penicillium sp. T2-M20 which was obtained from the parental strain Penicillium sp. T2-8 via UV irradiation as well as nitrosoguanidine (NTG) induction. Peniterester was only produced by the mutant T2-M20 on the basis of LC-MS analysis. Meanwhile, the results of in vitro bioactivities screening indicated that peniterester owned obvious antibacterial activities against Bacillus subtilis, Escherichia coli and Staphylococcus aureus with MICs of 8.0, 8.0 and 4.0 µg/mL, respectively.
Assuntos
Antibacterianos/farmacologia , Penicillium/química , Sesquiterpenos/farmacologia , Antibacterianos/isolamento & purificação , Bacillus subtilis/efeitos dos fármacos , Linhagem Celular Tumoral , China , Escherichia coli/efeitos dos fármacos , Gastrodia/microbiologia , Humanos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Rizoma/microbiologia , Metabolismo Secundário , Sesquiterpenos/isolamento & purificação , Staphylococcus aureus/efeitos dos fármacosRESUMO
An endophytic actinobacterium, designated strain KE2-3T, was isolated from surface-sterilised rhizome of Kaempferia elegans. The polyphasic approach was used for evaluating the taxonomic position of this strain. The taxonomic affiliation of this strain at genus level could be confirmed by its chemotaxonomic characteristic, i.e. the presence of ll-diaminopimelic acid in the cell peptidoglycan, MK-9(H4) as the major menaquinone, iso-C16â:â0, anteiso-C15â:â0, iso-C14â:â0 and iso-C15â:â0 as the predominant fatty acids in cells, and the presence of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol and phosphatidylinositol mannoside in its membranes. Based on 16S rRNA gene sequence analysis, strain KE2-3T was identified as a member of the genus Jiangella and showed the highest similarities to Jiangella muralis DSM 45357T (99.3â%) followed by Jiangella albaDSM 45237T (99.2â%), Jiangella alkaliphilia DSM 45079T (99.0â%), Jiangella gansuensisDSM 44835T (98.8â%) and Jiangella mangrovi3SM4-07T (98.6â%). However, the draft genome sequence of strain KE2-3T exhibited low average nucleotide identity values to the reference strains (85.5-90.2â%), which were well below the 95-96â% species circumscription threshold. The DNA G+C content of genomic DNA was 72.3 mol%. With the differences of physiological, biochemical and genotypic data, strain KE2-3T could be discriminated from its closest neighbour. Thus, strain KE2-3T should be recognised as a novel species of genus Jiangella, for which the name Jiangellaendophytica sp. nov. is proposed. The type strain is KE2-3T (=BCC 66359T=NBRC 110004T).
Assuntos
Actinobacteria/classificação , Filogenia , Rizoma/microbiologia , Zingiberaceae/microbiologia , Actinobacteria/isolamento & purificação , Técnicas de Tipagem Bacteriana , Composição de Bases , Sequência de Bases , Parede Celular/química , DNA Bacteriano/genética , Ácido Diaminopimélico/química , Ácidos Graxos/química , Hibridização de Ácido Nucleico , Peptidoglicano/química , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Tailândia , Vitamina K 2/análogos & derivados , Vitamina K 2/químicaRESUMO
Rhizome rot of turmeric caused by Pythium aphanidermatum is a major threat to turmeric-cultivating areas of India. This study intends to evaluate the performance of fluorescent pseudomonads against Rhizome rot disease and understand the resistance mechanism in Turmeric plants. Fluorescent pseudomonads were screened against Pythium aphanidermatum using dual culture. Selected strains were evaluated for the performance of growth promoting attributes and the presence of antibiotic genes through PCR analysis. Strain FP7 recorded the maximum percent inhibition of P. aphanidermatum under in vitro conditions. Strains FP7 and TPF54 both increased plant growth in turmeric plants in vitro. Strain FP7 alone contained all the evaluated antibiotic biosynthetic genes. Talc and liquid-based formulations were prepared with effective strain and tested for its biocontrol activities under both glasshouse and field conditions. Enzymatic activities of the induced defense enzymes such as PO, PPO, PAL, CAT and SOD were estimated and subjected to spectrophotometric analysis. A combination of rhizome dip and soil drench of FP7 liquid formulation treatment remarkably recorded the minimum disease incidence, higher defense enzymes, maximum plant growth and yield under glasshouse and field conditions. Application of strain FP7 increased the defense molecules, plant growth and yield in turmeric plants thereby reducing the incidence of rhizome rot disease. Moreover, this study has a potential to be adopted for sustainable and eco-friendly turmeric production.
Assuntos
Antibacterianos/biossíntese , Antibacterianos/farmacologia , Curcuma/crescimento & desenvolvimento , Curcuma/microbiologia , Resistência à Doença , Desenvolvimento Vegetal/efeitos dos fármacos , Pseudomonas fluorescens/metabolismo , Rizoma/microbiologia , Antibacterianos/química , Antifúngicos/química , Antifúngicos/metabolismo , Antifúngicos/farmacologia , Agentes de Controle Biológico/química , Agentes de Controle Biológico/metabolismo , Agentes de Controle Biológico/farmacologia , Catalase/metabolismo , Catecol Oxidase/metabolismo , Curcuma/efeitos dos fármacos , Genes Bacterianos/genética , Índia , Peroxidase/metabolismo , Fenilalanina Amônia-Liase/metabolismo , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle , Pseudomonas fluorescens/genética , Pythium/efeitos dos fármacos , Pythium/patogenicidade , Rizoma/enzimologia , Microbiologia do SoloRESUMO
We identified a new cyclic lipodepsipeptide, cystargamide B (1), from the mycelial extract of a Kaempferia galanga rhizome-derived actinomycete strain, Streptomyces sp. PB013. The planar structure was elucidated based on high resolution fast-atom bombardment mass spectrometry (HRFABMS) spectroscopy and one-dimensional (1D) and two-dimensional (2D) nuclear magnetic resonance (NMR) spectroscopic data. The absolute configurations of the constituent amino acids were determined using advanced Marfey's method. Cystargamide B (1) includes rare structural units: a 5-hydroxytryptophan residue and a 2,3-epoxy fatty acid side chain. Notably, cystargamide B (1) inhibited the protease activity of the NS2B/NS3 complex from dengue virus.
Assuntos
Depsipeptídeos/isolamento & purificação , Depsipeptídeos/farmacologia , Inibidores de Proteases/isolamento & purificação , Inibidores de Proteases/farmacologia , Streptomyces/química , Vírus da Dengue/enzimologia , Espectroscopia de Ressonância Magnética , Conformação Molecular , Rizoma/microbiologia , Espectrometria de Massas de Bombardeamento Rápido de Átomos , Zingiberaceae/microbiologiaRESUMO
The legume-rhizobial symbiosis results in the formation of root nodules that provide an ecological niche for nitrogen-fixing bacteria. However, plant-bacteria genotypic interactions can lead to wide variation in nitrogen fixation efficiency, and it is not uncommon that a bacterial strain forms functional (Fix+) nodules on one plant genotype but nonfunctional (Fix-) nodules on another. Host genetic control of this specificity is unknown. We herein report the cloning of the Medicago truncatula NFS1 gene that regulates the fixation-level incompatibility with the microsymbiont Sinorhizobium meliloti Rm41. We show that NFS1 encodes a nodule-specific cysteine-rich (NCR) peptide. In contrast to the known role of NCR peptides as effectors of endosymbionts' differentiation to nitrogen-fixing bacteroids, we demonstrate that specific NCRs control discrimination against incompatible microsymbionts. NFS1 provokes bacterial cell death and early nodule senescence in an allele-specific and rhizobial strain-specific manner, and its function is dependent on host genetic background.
Assuntos
Medicago truncatula , Fixação de Nitrogênio/fisiologia , Proteínas de Plantas , Rizoma , Nódulos Radiculares de Plantas , Sinorhizobium meliloti/metabolismo , Simbiose/fisiologia , Transaminases , Medicago truncatula/genética , Medicago truncatula/metabolismo , Medicago truncatula/microbiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Rizoma/genética , Rizoma/metabolismo , Rizoma/microbiologia , Nódulos Radiculares de Plantas/genética , Nódulos Radiculares de Plantas/metabolismo , Nódulos Radiculares de Plantas/microbiologia , Transaminases/genética , Transaminases/metabolismoRESUMO
In legume nodules, rhizobia differentiate into nitrogen-fixing forms called bacteroids, which are enclosed by a plant membrane in an organelle-like structure called the symbiosome. In the Inverted Repeat-Lacking Clade (IRLC) of legumes, this differentiation is terminal due to irreversible loss of cell division ability and is associated with genome amplification and different morphologies of the bacteroids that can be swollen, elongated, spherical, and elongated-branched, depending on the host plant. In Medicago truncatula, this process is orchestrated by nodule-specific cysteine-rich peptides (NCRs) delivered into developing bacteroids. Here, we identified the predicted NCR proteins in 10 legumes representing different subclades of the IRLC with distinct bacteroid morphotypes. Analysis of their expression and predicted sequences establishes correlations between the composition of the NCR family and the morphotypes of bacteroids. Although NCRs have a single origin, their evolution has followed different routes in individual lineages, and enrichment and diversification of cationic peptides has resulted in the ability to impose major morphological changes on the endosymbionts. The wide range of effects provoked by NCRs such as cell enlargement, membrane alterations and permeabilization, and biofilm and vesicle formation is dependent on the amino acid composition and charge of the peptides. These effects are strongly influenced by the rhizobial surface polysaccharides that affect NCR-induced differentiation and survival of rhizobia in nodule cells.
Assuntos
Proteínas de Bactérias/metabolismo , Medicago truncatula/microbiologia , Peptídeos/metabolismo , Rhizobiaceae/metabolismo , Rizoma/microbiologia , Simbiose/fisiologia , Proteínas de Bactérias/genética , Peptídeos/genética , Rhizobiaceae/genéticaRESUMO
Tissue culture and mycorrhiza applications can provide disease-free seedlings and enhanced nutrient absorption, respectively, for organic farming. Ginger (Zingiber officinale Roscoe) is rich in phytochemicals and has various health-protective potentials. This study was aimed at determining effects of tissue culture and mycorrhiza applications alone or in combinations in organic farming on phytochemical contents (total phenolics and flavonoids [TP and TF, respectively], gingerol and shogaol homologues, phenolic acids, and carotenoids) and antioxidant capacities (DPPH [2,2-diphenyl-1-picrylhydrazyl] radical scavenging, oxygen radical absorbance (ORAC), and iron-chelating capacities [ICC]) in solvent-extractable (Free) and cell-wall-matrix-bound (Bound) fractions of ginger rhizome and Free fraction of the leaves in comparison with non-organics. Concentrations of the phytochemicals and antioxidant capacities, except for carotenoids and ICC, were significantly higher in organic ginger rhizomes and leaves than in non-organics regardless of the fractions and treatments (P < 0.05). Mycorrhiza application in organic farming significantly increased levels of TP, TF, gingerols, and ORAC in the Free fraction of the rhizome (P < 0.05). Furthermore, the combined application of tissue culture and mycorrhiza significantly increased concentrations of TF and gingerols and ORAC in the Free fraction of the rhizome (P < 0.05), suggesting their synergistic effects. Considerable amounts of phenolics were found in the Bound fractions of the rhizomes. Six-gingerol, ferulic acid, and lutein were predominant ones among gingerols, phenolic acids, and carotenoids, respectively, in ginger rhizomes. The results suggest that organic farming with mycorrhiza and tissue culture applications can increase concentrations of phytochemicals and antioxidant capacities in ginger rhizomes and leaves and therefore improve their health-protective potentials.
Assuntos
Antioxidantes/análise , Micorrizas , Compostos Fitoquímicos/análise , Folhas de Planta/microbiologia , Rizoma/microbiologia , Zingiber officinale/microbiologia , Catecóis/análise , Ácidos Cumáricos/análise , Álcoois Graxos/análise , Flavonoides/análise , Zingiber officinale/química , Hidroxibenzoatos/análise , Luteína/análise , Agricultura Orgânica , Fenóis/análise , Folhas de Planta/química , Rizoma/químicaRESUMO
In this paper, the varying pattern of the amount of rhizospheric microorganisms, including bacteria, actinomycetes and fungus, was observed during the cultivation of Paris polyphylla var. yunnanensis. And the correlations between number of rhizospheric microorganisms and the quality of P. polyphylla var. yunnanensis were also studied. The results showed that the rhizospheric microorganism source of P. polyphylla var. yunnanensis was rich. The distribution of rhizospheric microorganisms (soil bacteria, fungus, actinomycetes, potassium-solubilizing bacteria, inorganic phosphorus-solubilizing bacteria, organic phosphorus-solubilizing bacteria) collected from different origin places existed significant difference (P < 0.05). The varying pattern for the amount of rhizospheric microorganisms was showed as following: the amount of bacteria > the amount of actinomycetes > the amount of fungus. The medicinal quality of P. polyphylla var. yunnanensis was influenced by their habits, and the increase of cultivation years caused the obvious decrease of the quality of P. polyphylla var. yunnanensis. Therefore, the increase of cultivation years will cause the variation of the soil micro-ecology flora, and decrease the nutrient absorption and the utilization of P. polyphylla var. yunnanensis, which will make the decrease of the medical quality of P. polyphylla var. yunnanensis.
Assuntos
Bactérias/isolamento & purificação , Fungos/isolamento & purificação , Liliaceae/química , Extratos Vegetais/análise , Rizosfera , Saponinas/análise , Microbiologia do Solo , Bactérias/genética , Bactérias/crescimento & desenvolvimento , Biodiversidade , China , Fungos/genética , Fungos/crescimento & desenvolvimento , Liliaceae/microbiologia , Rizoma/química , Rizoma/microbiologiaRESUMO
Through potted inoculation test at room temperature and indoor analysis, the photosynthetic parameters and physiological and biochemical indexes of Paris polyphylla var. yunnanensis were observed after 28 arbuscular mycorrhizal (AM) fungi were injected into the P. polyphylla var. yunnanensis growing in a sterile soil environment. The results showed that AM fungi established a good symbiosis with P. polyphylla var. yunnanensis. The AM fungi influenced the photosynthetic parameters and physiological and biochemical indexes of P. polyphylla var. yunnanensis. And the influences were varied depending on different AM fungi. The application of AM fungi improved photosynthesis intensity of P. polyphylla var. yunnanensis mesophyll cells, the contents of soluble protein and soluble sugar, protective enzyme activity of P. polyphylla var. yunnanensis leaf, which was beneficial to resist the adverse environment and promote the growth of P. polyphylla var. yunnanensis. Otherwise, there was a certain mutual selectivity between P. polyphylla var. yunnanensis and AM fungi. From the comprehensive effect of inoculation, Racocetra coralloidea, Scutellospora calospora, Claroideoglomus claroideum, S. pellucida and Rhizophagus clarus were the most suitable AM fungi to P. polyphylla var. yunnanensis when P. polyphylla var. yunnanensis was planted in the field.
Assuntos
Fungos/fisiologia , Liliaceae/metabolismo , Liliaceae/microbiologia , Micorrizas/fisiologia , Fotossíntese , Fungos/classificação , Fungos/isolamento & purificação , Micorrizas/classificação , Micorrizas/isolamento & purificação , Folhas de Planta/metabolismo , Rizoma/microbiologiaRESUMO
The soilborne Oomycete Pythium aphanidermatum is the causal agent of rhizome rot disease, one of the most serious threats to turmeric crops. At present, effective fungicides are not available. Researches on nanoparticles in a number of crops have evidenced the positive changes in gene expression indicating their potential use in crop improvement. Hence, experiments were carried out to determine the effect of ß-D-glucan nanoparticles (nanobiopolymer) in protection of turmeric plants against rot disease by the way of products that reinforce plant's own defense mechanism. Foliar spray of ß-D-glucan nanoparticles (0.1%, w/v) elicited marked increase in the activity of defense enzymes such as peroxidases (E.C.1.11.1.7), polyphenol oxidases (E.C.1.14.18.1), protease inhibitors (E.C.3.4.21.1) and ß-1,3-glucanases (E.C.3.2.1.39) at various age levels. Constitutive and induced isoforms of these enzymes were investigated during this time-course study. ß-D-glucan nanoparticles (GNPs) significantly reduced the rot incidence offering 77% protection. Increased activities of defense enzymes in GNPs-applied turmeric plants may play a role in restricting the development of disease symptoms. These results demonstrated that GNPs could be used as an effective resistance activator in turmeric for control of rhizome rot disease.
Assuntos
Curcuma/microbiologia , Nanopartículas/química , Doenças das Plantas/prevenção & controle , Folhas de Planta/efeitos dos fármacos , Rizoma/microbiologia , beta-Glucanas/farmacologia , Catecol Oxidase/metabolismo , Curcuma/efeitos dos fármacos , Curcuma/enzimologia , Glucosidases/metabolismo , Peroxidase/metabolismo , Doenças das Plantas/microbiologia , Inibidores de Proteases/metabolismo , Rizoma/efeitos dos fármacos , Rizoma/enzimologiaRESUMO
Endophyte microorganisms live inside plants without causing them any apparent damage. Recently, endophytic microorganisms have attracted attention because they can produce bioactive compounds of biotechnological interest. The endophytic microorganisms in Paris polyphylla var. yunnanensis (Liliaceae) - a species used since antiquity in traditional Chinese medicine - are under scrutiny because they may be responsible for producing the bioactive metabolites associated with the plant. The levels of bioactive metabolites in the rhizomes of P. polyphylla increase with rhizome age. To elucidate the roles played by endophytes in the accumulation of bioactive metabolites, we investigated the community structure and diversity of the endophytic microorganisms in P. polyphylla rhizomes of different ages (4, 6, and 8 years) using 16S rRNA and internal transcribed spacer (ITS) sequence analysis. 16S rDNA amplicon pyrosequencing revealed that the number of operational taxonomic units was lower in the 8-year-old samples than in the other samples. A total of 28 phyla were observed in the P. polyphylla samples and the predominant bacteria were of the Cyanobacteria and Proteobacteria phyla. Moreover, the percentage of Cyanobacteria increased with rhizome age. Similarly, ITS1 amplicon pyrosequencing identified developmental changes in the most abundant fungal classes; some classes were more prevalent in the 8-year-old rhizomes than in younger rhizomes, indicating the importance in secondary metabolism in older rhizomes. Our study showed that endophyte microorganism diversity and prevalence depend on P. polyphylla rhizome age. There was also an indication that some endophyte microorganisms contribute to the higher saponin content in older P. polyphylla specimens.
Assuntos
Cianobactérias/genética , Liliaceae/genética , Proteobactérias/genética , RNA Ribossômico 16S/genética , Rizoma/microbiologia , Bactérias/genética , Cianobactérias/isolamento & purificação , Endófitos/genética , Liliaceae/microbiologia , Medicina Tradicional Chinesa , Proteobactérias/isolamento & purificação , Rizoma/genéticaRESUMO
BACKGROUND: Plant growth promoting rhizobacteria (PGPR) are functionally diverse group of bacteria having immense potential as biofertilizers and biopesticides. Depending upon their function, they may serve as partial replacements for chemical fertilizer or pesticides as an eco-friendly and cost-effective alternatives as compared to their synthetic counterparts. Therefore, isolation, characterization and practical evaluation of PGPRs having the aforementioned multifaceted beneficial characteristics, are essentially required. This study describes the detailed polyphasic characterization of Bacillus sp. strain RMB7 having profound broad spectrum antifungal activity and plant growth promoting potential. RESULTS: Based on 16S rRNA gene sequencing, strain RMB7 was identified as Bacillus specie. This strain exhibited the production of 8 mg. L(-1)of indole-3-acetic acid (IAA) in tryptophan-supplemented medium. It was able to solubilize 50.6 mg. L(-1) tri-calcium phosphate, reduced 601ηmol acetylene h(-1)/vial and inhibited >70% growth of nine fungal phytopathogens tested in vitro. Under natural pathogen pressure, inoculation with strain RMB7 and RMB7-supernatant conferred resistance by arugula plant against Pythium irregulare with a concurrent growth improvement over non-inoculated plants. The T-RFLP analysis based on 16S rRNA gene showed that inoculation with RMB7 or its supernatant have a major impact on the indigenous rhizosphere bacterial population. Mass spectrometric analysis revealed the production of lipopeptide surfactins as well as iturin A presence in crude extract of RMB7. PCR-amplification further confirmed the presence of genes involved in the biosynthesis of these two bioactive lipopeptide compounds. CONCLUSIONS: The data show that Bacillus sp. strain RMB7 has multifaceted beneficial characteristics. It may be an ideal plant growth promoting as well as biocontrol agent, for its integrated use in disease and nutrient management strategies.
Assuntos
Bacillus , Pythium , Rizoma , Acetileno/metabolismo , Antifúngicos/metabolismo , Bacillus/genética , Bacillus/isolamento & purificação , Bacillus/metabolismo , Ácidos Indolacéticos/metabolismo , Pythium/crescimento & desenvolvimento , Pythium/microbiologia , RNA Ribossômico 16S/genética , Rizoma/crescimento & desenvolvimento , Rizoma/microbiologiaRESUMO
This study was conducted to investigate the use of elevated carbon dioxide (CO2), plant growth-promoting rhizobacterium Burkholderia sp. D54 (PGPR) and ethylenediaminetetraacetic acid (EDTA) to enhance the phytoextraction efficiency of ryegrass in response to multiple heavy metal (or metalloid)-polluted soil containing zinc (Zn), arsenic (As), cadmium (Cd) and lead (Pb). All of the single or combined CO2, PGPR and EDTA treatments promoted ryegrass growth. The stimulation of ryegrass growth by CO2 and PGPR could primarily be attributed to the regulation of photosynthesis rather than decreased levels of Zn, As and Cd in the shoots. Most treatments seemed to reduce the Zn, As and Cd contents in the shoots, which might be associated with enhanced shoot biomass, thus causing a "dilution effect" regarding their levels. The combined treatments seemed to perform better than single treatments in removing Zn, As, Cd and Pb from soil, judging from the larger biomass and relatively higher total amounts (TAs) of Zn, As, Cd and Pb in both the shoots and roots. Therefore, we suggest that the CO2 plus PGPR treatment will be suitable for removing Zn, As, Cd and Pb from heavy metal (or metalloid)-polluted soils using ryegrass as a phytoremediation material.
Assuntos
Burkholderia , Dióxido de Carbono/farmacologia , Ácido Edético/farmacologia , Lolium/metabolismo , Rizoma/microbiologia , Poluentes do Solo/metabolismo , Arsênio/metabolismo , Biodegradação Ambiental , Biomassa , Quelantes/farmacologia , Lolium/efeitos dos fármacos , Lolium/crescimento & desenvolvimento , Lolium/microbiologia , Metais Pesados/metabolismo , Desenvolvimento Vegetal , Raízes de Plantas/química , Rizoma/efeitos dos fármacos , Rizoma/crescimento & desenvolvimento , Rizoma/metabolismoRESUMO
Micrococcus sp. MU1 and Klebsiella sp. BAM1, the cadmium-resistant plant growth-promoting rhizobacteria (PGPR), produce high levels of indole-3-acetic acid (IAA) during the late stationary phase of their growth. The ability of PGPR to promote root elongation, plant growth and cadmium uptake in sunflowers (Helianthus annuus) was evaluated. Both species of bacteria were able to remove cadmium ions from an aqueous solution and enhanced cadmium mobilization in contaminated soil. Micrococcus sp. and Klebsiella sp. use aminocyclopropane carboxylic acid as a nitrogen source to support their growth, and the minimum inhibitory concentrations of cadmium for Micrococcus sp. and Klebsiella sp. were 1000 and 800mM, respectively. These bacteria promoted root elongation in H. annuus seedlings in both the absence and presence of cadmium compared to uninoculated seedlings. Inoculation with these bacteria was found to increase the root lengths of H. annuus that had been planted in cadmium-contaminated soil. An increase in dry weight was observed for H. annuus inoculated with Micrococcus sp. Moreover, Micrococcus sp. enhanced the accumulation of cadmium in the root and leaf of H. annuus compared to untreated plants. The highest cadmium accumulation in the whole plant was observed when the plants were treated with EDTA following the treatment with Micrococcus sp. In addition, the highest translocation of cadmium from root to the above-ground tissues of H. annuus was found after treatment with Klebsiella sp. in the fourth week after planting. Our results show that plant growth and cadmium accumulation in H. annuus was significantly enhanced by cadmium-resistant PGPRs, and these bacterial inoculants are excellent promoters of phytoextraction for the rehabilitation of heavy metal-polluted environments.
Assuntos
Cádmio/isolamento & purificação , Helianthus/microbiologia , Helianthus/fisiologia , Klebsiella/fisiologia , Micrococcus/fisiologia , Poluentes do Solo/isolamento & purificação , Biodegradação Ambiental , Cádmio/metabolismo , Rizoma/microbiologia , Rizoma/fisiologia , Poluentes do Solo/metabolismoRESUMO
To compare the effects of inoculated or non-inoculated with arbuscular mycorrhizal (AM) fungi on the steroidal saponin component in root of Paris polyphylla var. yunnanensis. By pot experiments, steroid saponin component in root of P. polyphylla var. yunnanensis was determined and compared by HPLC. The results showed there was difference in the effects of different AM fungal on the secondary metabolite steroid saponin in P. polyphylla var. yunnanensis. After elicitors treatment, AM fungal did not change the chemical backgrounds of P. polyphylla var. yunnanensis, but can improve partly the content of chemical compositions in roots. In conclusion, there was selectivity between AM fungal and P. polyphylla var. yunnanensis. Glomus intraradices was the most appropriate strain for inoculation P. polyphylla var. yunnanensis.
Assuntos
Liliaceae/química , Liliaceae/microbiologia , Micorrizas/crescimento & desenvolvimento , Saponinas/metabolismo , Plantas Medicinais/química , Plantas Medicinais/microbiologia , Rizoma/química , Rizoma/microbiologiaRESUMO
Lipopolysaccharide (LPS) can produce endotoxic shock by triggering the systemic inflammatory response. Here, we evaluated the in vitro and in vivo protective effects of unfermented and fermented Rhizoma coptidis (RC and FRC, respectively) against LPS-insult. In general, RC suppressed the LPS-induced expression of key inflammatory mediators in RAW264.7 cells, in a dose-dependent manner. Notably, FRC at a 20 µg/ml dose in combination with the probiotic used for fermentation showed more potent in vitro anti-inflammatory activities than that exhibited by the corresponding dose of RC. Moreover, oral treatment with FRC in association with the probiotic, but not oral administration of RC, significantly attenuated blood endotoxin and C-reactive protein (CRP) levels, and gut permeability, and significantly augmented the intestinal population of Bifodobacterium spp. and Lactobacillus spp. in LPS-treated animals. Our results demonstrate the beneficial impact of fermented RC in combination with the associated probiotic in combating LPS-insult both in vitro and in vivo.