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1.
Artigo em Inglês | MEDLINE | ID: mdl-31474083

RESUMO

Banana planting altered microbial communities and induced the enrichment of Fusarium oxysporum in rhizosphere compared with that of forest soil. Diseased plant rhizosphere soil (WR) harboured increased pathogen abundance and showed distinct microbial structures from healthy plant rhizosphere soil (HR). The enriched taxon of Bordetella and key taxon of Chaetomium together with some other taxa showed negative associations with pathogen in HR, indicating their importance in pathogen inhibition. Furthermore, more stable microbiota was observed in HR than in WR. Taken together, the lower pathogen abundance, specific beneficial microbial taxa and stable microbiota contributed to disease suppression.

2.
FEMS Microbiol Ecol ; 95(10)2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31504451

RESUMO

Rhizosphere community assembly is simultaneously affected by both plants and bulk soils and is vital for plant health. However, it is still unclear how and to what extent disease-suppressive rhizosphere microbiota can be constructed from bulk soil, and the underlying agents involved in the process that render the rhizosphere suppressive against pathogenic microbes remain elusive. In this study, the evolutionary processes of the rhizosphere microbiome were explored based on transplanting plants previously growing in distinct disease-incidence soils to one disease-suppressive soil. Our results showed that distinct rhizoplane bacterial communities were assembled on account of the original bulk soil communities with different disease incidences. Furthermore, the bacterial communities in the transplanted rhizosphere were noticeably influenced by the second disease-suppressive microbial pool, rather than that of original formed rhizoplane microbiota and homogenous nontransplanted rhizosphere microbiome, contributing to a significant decrease in the pathogen population. In addition, Spearman's correlations between relative abundances of bacterial taxa and the abundance of Ralstonia solanacearum indicated Anoxybacillus, Flavobacterium, Permianibacter and Pseudomonas were predicted to be associated with disease-suppressive function formation. Altogether, our results showed that bulk soil played an important role in the process of assembling and reassembling the rhizosphere microbiome of plants.

3.
Bioresour Technol ; 288: 121576, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31176934

RESUMO

A consortium of key bacterial taxa plays critical roles in the composting process. In order to elucidate the identity and mechanisms by which specific bacterial species drive high-efficiency composting, the succession of key bacterial consortia and extracellular enzymes produced during the composting process were monitored in composting piles with varying initial C/N ratios. Results showed that C/N ratios of 25 and 35 enhanced composting efficiency through elevated temperatures, higher germination indices, enhanced cellulose and hemicellulose degradation, and higher cellulase and dehydrogenase activities. The activities of cellulase and ß-glucosidase, cellulase and protease, and cellulase and ß-glucosidase exhibited significant relationships with bacterial community composition within the mesophilic, thermophilic, and mature phases, respectively. Putative key taxa, linked to a higher composting efficiency, such as Nonomuraea, Desemzia, Cellulosimicrobium, Virgibacillus, Clostridium, and Achromobacter, exhibited significantly positive relationships with extracellular enzyme activities, suggesting a significant contribution to these taxa to the development of composting maturity.


Assuntos
Celulase , Compostagem , Bactérias , Celulose , Solo , beta-Glucosidase
4.
Microb Biotechnol ; 12(3): 515-527, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30838803

RESUMO

Microbiome plays a key role in determining soil suppressiveness against invading pathogens. Our previous study revealed that microbial community of bulk soil could be manipulated by lime and ammonium bicarbonate fumigation followed by biofertilizer application. However, the assembly of microbial community suppressive to banana Panama disease in the rhizosphere is still unclear. In this study, we used high-throughput sequencing and quantitative PCR to explore the assembly of rhizosphere microbiome associated with banana Panama disease suppression in a two-seasonal pot experiment. We found biofertilizer applied to lime and ammonium bicarbonate fumigated soil significantly (P < 0.05) reduced the abundance of rhizosphere Fusarium oxysporum compared to biofertilizer applied to non-fumigated soil. Principal coordinate analysis revealed that biofertilizer applied to lime and ammonium bicarbonate fumigated soil re-shaped the rhizosphere bacterial community composition by increasing the phylogenetic relatedness, and stimulating indigenous microbes, for example, Gemmatimonas, Sphingomonas, Pseudomonas, Lysobacter and Bacillus. Co-occurrence analysis revealed that potential species involved in disease suppression were more interrelated in disease-suppressive soils. Taken together, lime and ammonium bicarbonate fumigation followed by biofertilizer application could induce banana rhizosphere to assemble beneficial microbes dominated consortia to suppress banana Panama disease.


Assuntos
Biota/efeitos dos fármacos , Compostos de Cálcio/metabolismo , Carbonatos/metabolismo , Fertilizantes , Fumigação , Óxidos/metabolismo , Doenças das Plantas/prevenção & controle , Microbiologia do Solo , Bactérias/classificação , Bactérias/genética , Fusarium/isolamento & purificação , Sequenciamento de Nucleotídeos em Larga Escala , Musa/crescimento & desenvolvimento , Reação em Cadeia da Polimerase em Tempo Real , Rizosfera
5.
Microb Ecol ; 75(3): 739-750, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28791467

RESUMO

The continuous cropping of banana in the same field may result in a serious soil-borne Fusarium wilt disease and a severe yield decline, a phenomenon known as soil sickness. Although soil microorganisms play key roles in maintaining soil health, the alternations of soil microbial community and relationship between these changes and soil sickness under banana monoculture are still unclear. Bacterial and fungal communities in the soil samples collected from banana fields with different monoculture spans were profiled by sequencing of the 16S rRNA genes and internal transcribed spacer using the MiSeq platform to explore the relationship between banana monoculture and Fusarium wilt disease in the present study. The results showed that successive cropping of banana was significantly correlated with the Fusarium wilt disease incidence. Fungal communities responded more obviously and quickly to banana consecutive monoculture than bacterial community. Moreover, a higher fungal richness significantly correlated to a higher banana Fusarium wilt disease incidence but a lower yield. Banana fungal pathogenic genus of Fusarium and Phyllosticta were closely associated with banana yield depletion and disease aggravation. Potential biocontrol agents, such as Funneliformis, Mortierella, Flavobacterium, and Acidobacteria subgroups, exhibited a significant correlation to lower disease occurrence. Further networks analysis revealed that the number of functionally interrelated modules decreased, the composition shifted from bacteria- to fungi-dominated among these modules, and more resources-competitive interactions within networks were observed after banana long-term monoculture. Our results also showed that bacterial and fungal communities were mainly driven by soil organic matter. Overall, the findings indicated that the bacterial and fungal community structures altered significantly after banana long-term monoculture, and the fungal richness, abundance of Fusarium, interactions between and within bacteria and fungi in ecological networks, and soil organic matter were associated with banana soil-borne Fusarium wilt disease.

6.
Front Microbiol ; 8: 2070, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29123509

RESUMO

Banana production is seriously hindered by Meloidogyne spp. all over the world. Endophytes are ideal candidates compared to pesticides as an environmentally benign agent. In the present study, endophytes isolated from banana roots infected by Meloidogyne spp. with different disease levels were tested in vitro, and in sterile and nature banana monoculture soils against Meloidogyne javanica. The proportion of antagonistic endophytes were higher in the roots of middle and high disease levels. Among those, bacteria were dominant, and Pseudomonas spp., Bacillus spp. and Streptomyces spp. showed more abundant populations. One strain, named as SA, with definite root inner-colonization ability was isolated and identified as Streptomyces sp. This strain showed an inhibiting rate of >50% in vitro and biocontrol efficiency of 70.7% in sterile soil against Meloidogyne javanica, compared to the control. Greenhouse experiment results showed that the strain SA exhibits excellent biological control ability for plant-parasites both in roots and in root-knot nematode infested soil. SA treatment showed a higher number of bacterivores, especially Mesorhabditis and Cephalobus. The maturity index was significantly lower, while enrichment index (EI) was significantly higher in the SA treatment. In conclusion, this study presents an important potential application of the endophytic strain Streptomyces sp. for the control of plant-parasitic nematodes, especially Meloidogyne javanica, and presents the effects on the associated variation of the nematode community.

8.
Sci Rep ; 5: 11124, 2015 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-26242751

RESUMO

Panama disease caused by Fusarium oxysporum f. sp. cubense infection on banana is devastating banana plantations worldwide. Biological control has been proposed to suppress Panama disease, though the stability and survival of bio-control microorganisms in field setting is largely unknown. In order to develop a bio-control strategy for this disease, 16S rRNA gene sequencing was used to assess the microbial community of a disease-suppressive soil. Bacillus was identified as the dominant bacterial group in the suppressive soil. For this reason, B. amyloliquefaciens NJN-6 isolated from the suppressive soil was selected as a potential bio-control agent. A bioorganic fertilizer (BIO), formulated by combining this isolate with compost, was applied in nursery pots to assess the bio-control of Panama disease. Results showed that BIO significantly decreased disease incidence by 68.5%, resulting in a doubled yield. Moreover, bacterial community structure was significantly correlated to disease incidence and yield and Bacillus colonization was negatively correlated with pathogen abundance and disease incidence, but positively correlated to yield. In total, the application of BIO altered the rhizo-bacterial community by establishing beneficial strains that dominated the microbial community and decreased pathogen colonization in the banana rhizosphere, which plays an important role in the management of Panama disease.


Assuntos
Musa/microbiologia , Doenças das Plantas/prevenção & controle , Rizosfera , Bacillus/classificação , Bacillus/genética , Sequência de Bases , Agentes de Controle Biológico/farmacologia , Fusarium/efeitos dos fármacos , Fusarium/crescimento & desenvolvimento , Microbiota , Dados de Sequência Molecular , Musa/crescimento & desenvolvimento , Panamá , Filogenia , Doenças das Plantas/microbiologia , Raízes de Plantas/microbiologia , RNA Ribossômico 16S/química , RNA Ribossômico 16S/metabolismo , Análise de Sequência de DNA , Microbiologia do Solo
9.
Ying Yong Sheng Tai Xue Bao ; 26(2): 481-9, 2015 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-26094464

RESUMO

A field experiment was conducted for two years to investigate the effects of different fertilization applications on the suppression of banana fusarium wilt disease, crop yield, fruit quality and culturable microflora in a banana orchard which has been monocultured with banana for 12 years and suffered serious banana fusarium wilt disease. The fertilizers included chemical fertilizer (CF), cow manure compost (CM), pig manure compost (PM) and bio-organic fertilizer (BIO). The banana soil microflora was invested using plate-counting method and culture-dependent polymerase chain reaction denaturing gradient gel electrophoresis method (CD PCR-DGGE). Results showed that, compared with the other treatments, 2-year consecutive application of BIO significantly reduced the banana fusarium wilt disease incidence, and improved the banana mass per tree, crop yield, total soluble sugar content and the ratio of total soluble sugar to titratable acidity of fruits (sugar/acid ratio). Moreover, the analysis of culturable microflora showed that BIO application significantly increased the soil microbial biomass, soil culturable bacteria, bacillus and actinomycetes, and the ratio of bacteria to fungi (B/F) , while decreased the Fusarium oxysporum. Based on the CD PCR-DGGE results, the BIO application significantly altered the soil culturable bacterial structure and showed highest richness and diversity after 2 years of BIO application. The phylogenetic analysis of the selected bands showed that BIO application enriched the soil with the species of Paenibacillus sp., Burkholderia sp., uncultured Verrucomicrobia sp. and Bacillus aryabhattai, and depressed the species of Ralstonia sp., Chryseobacterium gleum, Fluviicola taffensis, Enterobacter sp. and Bacillus megaterium. These results confirmed that the continuous application of BIO effectively controlled the fusarium wilt disease, improved the crop yield and fruit quality, and modulated the soil culturable microflora under field condition.


Assuntos
Fertilizantes , Esterco , Musa/crescimento & desenvolvimento , Doenças das Plantas/microbiologia , Microbiologia do Solo , Animais , Bactérias , Biomassa , Bovinos , Fusarium , Musa/microbiologia , Filogenia , Solo , Suínos
10.
PLoS One ; 9(5): e98420, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24871319

RESUMO

Our previous work demonstrated that application of a bio-organic fertilizer (BIO) to a banana mono-culture orchard with serious Fusarium wilt disease effectively decreased the number of soil Fusarium sp. and controlled the soil-borne disease. Because bacteria are an abundant and diverse group of soil organisms that responds to soil health, deep 16 S rRNA pyrosequencing was employed to characterize the composition of the bacterial community to investigate how it responded to BIO or the application of other common composts and to explore the potential correlation between bacterial community, BIO application and Fusarium wilt disease suppression. After basal quality control, 137,646 sequences and 9,388 operational taxonomic units (OTUs) were obtained from the 15 soil samples. Proteobacteria, Acidobacteria, Bacteroidetes, Gemmatimonadetes and Actinobacteria were the most frequent phyla and comprised up to 75.3% of the total sequences. Compared to the other soil samples, BIO-treated soil revealed higher abundances of Gemmatimonadetes and Acidobacteria, while Bacteroidetes were found in lower abundance. Meanwhile, on genus level, higher abundances compared to other treatments were observed for Gemmatimonas and Gp4. Correlation and redundancy analysis showed that the abundance of Gemmatimonas and Sphingomonas and the soil total nitrogen and ammonium nitrogen content were higher after BIO application, and they were all positively correlated with disease suppression. Cumulatively, the reduced Fusarium wilt disease incidence that was seen after BIO was applied for 1-year might be attributed to the general suppression based on a shift within the bacteria soil community, including specific enrichment of Gemmatimonas and Sphingomonas.


Assuntos
Fertilizantes/microbiologia , Microbiota/genética , Musa/microbiologia , Doenças das Plantas/microbiologia , Microbiologia do Solo , Compostos de Amônio/análise , Análise de Variância , Sequência de Bases , China , Biologia Computacional , Fusarium/genética , Sequenciamento de Nucleotídeos em Larga Escala , Dados de Sequência Molecular , Nitrogênio/análise , Agricultura Orgânica/métodos , RNA Ribossômico 16S/genética , Solo/química , Especificidade da Espécie
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