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1.
PLoS One ; 15(11): e0242258, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33211760

RESUMO

Endophytic fungi play an important role in plant growth. The composition and structure of endophytes vary in different plant tissues, which are specific habitats for endophyte colonization. To analyze the diversity and structural composition of endophytic fungi from toothed clubmoss (Huperzia serrata) that was artificially cultivated for 3 years, we investigated endophytic fungi from the roots, stems and leaves using comparative sequence analysis of the ITS2 region of the fungal rRNA genes sequenced with high-throughput sequencing technology. Seven fungal phyla were identified, and fungal diversity and structure varied across different tissues, with the most distinctive community features found in the roots. A total of 555 operational taxonomic units (OTUs) were detected, and 198 were common to all samples, and 43, 16, 16 OTUs were unique to the root, stem, leaf samples, respectively. Taxonomic classification showed that Ascomycota and Basidiomycota were dominant phyla, and Cladosporium, Oidiodendron, Phyllosticta, Sebacina and Ilyonectria were dominant genera. The relative abundance heat map at the genus level suggested that H. serrata had characteristic endophytic fungal microbiomes. Line discriminant analysis effect size analysis and principal coordinate analysis demonstrated that fungal communities were tissue-type and tissue-site specific. Overall, our study provides new insights into the complex composition of endophytic fungi in H. serrata.


Assuntos
Fungos/genética , Huperzia/microbiologia , Ascomicetos/classificação , Ascomicetos/genética , Ascomicetos/isolamento & purificação , Basidiomycota/classificação , Basidiomycota/genética , Basidiomycota/isolamento & purificação , Fungos/classificação , Fungos/isolamento & purificação , Sequenciamento de Nucleotídeos em Larga Escala , Filogenia , Folhas de Planta/microbiologia , Raízes de Plantas/microbiologia , Caules de Planta/microbiologia , Análise de Componente Principal , RNA Ribossômico/química , RNA Ribossômico/genética , RNA Ribossômico/metabolismo , Análise de Sequência de DNA
2.
J Agric Food Chem ; 68(21): 5863-5872, 2020 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-32375483

RESUMO

In this study, the effect of soluble polysaccharides (SPs) derived from agricultural waste, rice straw, on fermentation-associated stresses (temperature and concentrations of glucose and ethanol) was investigated to achieve high-performance ethanol production. The increase in temperature and concentrations of glucose and ethanol significantly inhibited Saccharomyces cerevisiae growth and lowered ethanol fermentation efficiency. Flow cytometric assays indicated that SPs could alleviate membrane permeability damage caused by fermentation-associated stresses. Atomic force microscopy and transmission electron microscopy revealed that fermentation-associated stresses induced cell surface shrinkage, causing a decrease in the cell size, whereas SPs stimulated the formation of extracellular matrices (EMs), which made the cell surface smooth and the cell morphology regular. Cells with EMs induced by SPs could efficiently produce ethanol under severe stresses. As a result, the titer of ethanol in the fermentation with SPs was 1.40-fold (from 26.40 to 36.98 g/L) higher than that in the fermentation without SPs, suggesting the stress-alleviating effect of SPs on ethanol production.


Assuntos
Etanol/metabolismo , Saccharomyces cerevisiae/metabolismo , Biocombustíveis/análise , Fermentação , Glucose/metabolismo , Oryza/metabolismo , Oryza/microbiologia , Caules de Planta/metabolismo , Caules de Planta/microbiologia , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/crescimento & desenvolvimento , Resíduos/análise
3.
Plant Physiol Biochem ; 151: 292-298, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32251954

RESUMO

The effects of two purified fractions (formerly D-SXM and ND-SXM) produced in vitro by defoliating (Vd312D) and non-defoliating (Vd315ND) strains of Verticillium dahliae were studied on twigs of Olea europaea cvs Frantoio and Leccino. Symptoms, such as leaf curling, yellowing, vein clearing and defoliation, which are observed on the two cultivars naturally affected by Verticillium wilt, were produced by these fractions. Physiological changes were induced during the first seven days after the absorption of solutions containing ND-SXM or D-SXM. Both fractions increased the transpiration flow from abaxial leaf surfaces. Cell membrane and antioxidant activity were the most important action sites of ND-SXM and D-SXM. ND-SXM influenced malondialdehyde concentration in 'Leccino' leaves, while D-SXM increased the percentage of electrolyte leakage in 'Frantoio'. Both fractions reduced the total non-enzymatic antioxidant activity on the leaves of the treated twigs. The total phenol content increased in both cultivars, without differences to the control. Variations on electrolyte leakage and total antioxidant activity were effective in discriminating the two tested olive cultivars for V. dahliae tolerance or susceptibility. If V. dahliae strains Vd315ND and Vd312D produce ND-SXM and D-SXM in the infected plants, these metabolites may move via the xylem sap, accumulate in the leaves and induce changes that will lead symptoms on the leaf by compromising the cell membranes physiology.


Assuntos
Olea , Verticillium , Olea/microbiologia , Doenças das Plantas/microbiologia , Folhas de Planta/microbiologia , Caules de Planta/microbiologia , Verticillium/química , Xilema/metabolismo
4.
J Agric Food Chem ; 68(15): 4305-4314, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32227887

RESUMO

The rise of environmental and health concerns due to the excessive use of the conventional fungicide urges the search for sustainable alternatives of agronanofungicides where the latter is aimed to enhance plant uptake and minimize the volatilization, leaching, and runoff of fungicides. With this in mind, fungicides of hexaconazole and/or dazomet were encapsulated into chitosan nanoparticles for the formulation of chitosan-based agronanofungicides. In the present study, chitosan nanoparticles (2 nm), chitosan-hexaconazole nanoparticles (18 and 168 nm), chitosan-dazomet nanoparticles (7 and 32 nm), and chitosan-hexaconazole-dazomet nanoparticles (5 and 58 nm) were synthesized and used as potent antifungal agents in combating the basal stem rot (BSR) disease caused by Ganoderma boninense in which they were evaluated via an artificial inoculation of oil palm seedlings with the rubber woodblock, which was fully colonized with the fungal Ganoderma boninense mycelium. The results revealed that chitosan nanoparticles could act as dual modes of action, which are themselves as a biocide or as a nanocarrier for the existing fungicides. In addition, the particle size of the chitosan-based agronanofungicides plays a crucial role in suppressing and controlling the disease. The synergistic effect of the double-fungicide system of 5 nm chitosan-hexaconazole-dazomet nanoparticles can be observed as the system showed the highest disease reduction with 74.5%, compared to the untreated infected seedlings.


Assuntos
Quitosana/química , Fungicidas Industriais/farmacologia , Ganoderma/efeitos dos fármacos , Triazóis/farmacologia , Portadores de Fármacos/química , Composição de Medicamentos , Fungicidas Industriais/química , Ganoderma/fisiologia , Nanopartículas/química , Doenças das Plantas/microbiologia , Caules de Planta/microbiologia , Tiadiazinas/química , Tiadiazinas/farmacologia , Triazóis/química
5.
Sci Rep ; 10(1): 6464, 2020 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-32296108

RESUMO

Ground-based LiDAR also known as Terrestrial Laser Scanning (TLS) technology is an active remote sensing imaging method said to be one of the latest advances and innovations for plant phenotyping. Basal Stem Rot (BSR) is the most destructive disease of oil palm in Malaysia that is caused by white-rot fungus Ganoderma boninense, the symptoms of which include flattening and hanging-down of the canopy, shorter leaves, wilting green fronds and smaller crown size. Therefore, until now there is no critical investigation on the characterisation of canopy architecture related to this disease using TLS method was carried out. This study proposed a novel technique of BSR classification at the oil palm canopy analysis using the point clouds data taken from the TLS. A total of 40 samples of oil palm trees at the age of nine-years-old were selected and 10 trees for each health level were randomly taken from the same plot. The trees were categorised into four health levels - T0, T1, T2 and T3, which represents the healthy, mildly infected, moderately infected and severely infected, respectively. The TLS scanner was mounted at a height of 1 m and each palm was scanned at four scan positions around the tree to get a full 3D image. Five parameters were analysed: S200 (canopy strata at 200 cm from the top), S850 (canopy strata at 850 cm from the top), crown pixel (number of pixels inside the crown), frond angle (degree of angle between fronds) and frond number. The results taken from statistical analysis revealed that frond number was the best single parameter to detect BSR disease as early as T1. In classification models, a linear model with a combination of parameters, ABD - A (frond number), B (frond angle) and D (S200), delivered the highest average accuracy for classification of healthy-unhealthy trees with an accuracy of 86.67 per cent. It also can classify the four severity levels of infection with an accuracy of 80 per cent. This model performed better when compared to the severity classification using frond number. The novelty of this research is therefore on the development of new approach to detect and classify BSR using point clouds data of TLS.


Assuntos
Arecaceae/microbiologia , Monitorização de Parâmetros Ecológicos/métodos , Doenças das Plantas/microbiologia , Caules de Planta/microbiologia , Tecnologia de Sensoriamento Remoto/métodos , Monitorização de Parâmetros Ecológicos/instrumentação , Estudos de Viabilidade , Ganoderma/patogenicidade , Lasers , Malásia , Folhas de Planta/microbiologia , Tecnologia de Sensoriamento Remoto/instrumentação , Índice de Gravidade de Doença
6.
Sci Rep ; 10(1): 4599, 2020 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-32165688

RESUMO

Fungal endophytes are sources of novel bioactive compounds but relatively few agriculturally important fruiting plants harboring endophytes have been carefully studied. Previously, we identified a griseofulvin-producing Xylaria species isolated from Vaccinium angustifolium, V. corymbosum, and Pinus strobus. Morphological and genomic analysis determined that it was a new species, described here as Xylaria ellisii. Untargeted high-resolution LC-MS metabolomic analysis of the extracted filtrates and mycelium from 15 blueberry isolates of this endophyte revealed differences in their metabolite profiles. Toxicity screening of the extracts showed that bioactivity was not linked to production of griseofulvin, indicating this species was making additional bioactive compounds. Multivariate statistical analysis of LC-MS data was used to identify key outlier features in the spectra. This allowed potentially new compounds to be targeted for isolation and characterization. This approach resulted in the discovery of eight new proline-containing cyclic nonribosomal peptides, which we have given the trivial names ellisiiamides A-H. Three of these peptides were purified and their structures elucidated by one and two-dimensional nuclear magnetic resonance spectroscopy (1D and 2D NMR) and high-resolution tandem mass spectrometry (HRMS/MS) analysis. The remaining five new compounds were identified and annotated by high-resolution mass spectrometry. Ellisiiamide A demonstrated Gram-negative activity against Escherichia coli BW25113, which is the first reported for this scaffold. Additionally, several known natural products including griseofulvin, dechlorogriseofulvin, epoxy/cytochalasin D, zygosporin E, hirsutatin A, cyclic pentapeptides #1-2 and xylariotide A were also characterized from this species.


Assuntos
Mirtilos Azuis (Planta)/microbiologia , Metabolômica , Peptídeos Cíclicos/metabolismo , Xylariales/metabolismo , Teorema de Bayes , Cromatografia Líquida , DNA Espaçador Ribossômico , Metabolômica/métodos , Filogenia , Folhas de Planta/microbiologia , Caules de Planta/microbiologia , Espectrometria de Massas em Tandem , Xylariales/classificação , Xylariales/genética
7.
Pol J Microbiol ; 69(1): 91-97, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32189484

RESUMO

The root of Paris polyphylla var. yunnanensis, a famous and endangered traditional Chinese herb, has a significant medicinal value. The aim of this study was to analyze the composition and functional characteristics of bacterial endophytes in roots, stems, and leaves of P. polyphylla var. yunnanensis. The 16S rRNA gene sequencing and functional prediction of bacterial endophytes in roots, stems, and leaves of P. polyphylla var. yunnanensis were conducted. The Chao and Shannon indices of the bacteria in roots were significantly higher than those in stems and leaves. The dominant endophyte phyla were Cyanobacteria, Proteobacteria, Bacteroidetes, Firmicutes, and Actinobacteria. The main genera detected in roots were unclassified Cyanobacteria, Rhizobium, Flavobacterium, and Sphingobium; the main genera in stems were norank_c__Cyanobacteria, Bacillus, and Pseudomonas; the main genera in leaves were norank_c__Cyanobacteria and Rhizobium. The microbiota in roots was particularly enriched in functional categories "extracellular structures" and "cytoskeleton" compared with stems and leaves (p < 0.05). Our study reveals the structural and functional characteristics of the endophytic bacteria in roots, stems, and leaves of P. polyphylla var. yunnanensis, which aids in the scientific understanding of this plant.The root of Paris polyphylla var. yunnanensis, a famous and endangered traditional Chinese herb, has a significant medicinal value. The aim of this study was to analyze the composition and functional characteristics of bacterial endophytes in roots, stems, and leaves of P. polyphylla var. yunnanensis. The 16S rRNA gene sequencing and functional prediction of bacterial endophytes in roots, stems, and leaves of P. polyphylla var. yunnanensis were conducted. The Chao and Shannon indices of the bacteria in roots were significantly higher than those in stems and leaves. The dominant endophyte phyla were Cyanobacteria, Proteobacteria, Bacteroidetes, Firmicutes, and Actinobacteria. The main genera detected in roots were unclassified Cyanobacteria, Rhizobium, Flavobacterium, and Sphingobium; the main genera in stems were norank_c__Cyanobacteria, Bacillus, and Pseudomonas; the main genera in leaves were norank_c__Cyanobacteria and Rhizobium. The microbiota in roots was particularly enriched in functional categories "extracellular structures" and "cytoskeleton" compared with stems and leaves (p < 0.05). Our study reveals the structural and functional characteristics of the endophytic bacteria in roots, stems, and leaves of P. polyphylla var. yunnanensis, which aids in the scientific understanding of this plant.


Assuntos
Bactérias/classificação , Liliaceae/microbiologia , Folhas de Planta/microbiologia , Raízes de Plantas/microbiologia , Caules de Planta/microbiologia , Plantas Medicinais/microbiologia , Endófitos/classificação , Medicina Tradicional Chinesa
8.
Biomedica ; 40(1): 55-71, 2020 03 01.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-32220164

RESUMO

Introduction: Infectious diseases represent one of the leading causes of death worldwide. Considering the growing global challenge of antimicrobial resistance, research into new sources of potentially effective antimicrobial agents from natural origins is of great importance for world health. Objective: To evaluate the antimicrobial activity of endophytic fungi from Mammea americana and Moringa oleifera upon Staphylococcus aureus (ATCC 29213), S. aureus (resistant strain USb003), Escherichia coli (ATCC 25922), and E. coli (resistant strain USb007). Materials and methods: We isolated endophytic fungi from the leaves, seeds, and stems of the two plants under study. We evaluated their antimicrobial activity through the formation of sensitivity haloes in dual tests in vitro, as well as in trials using crude ethanolic extracts from the endophytes. The minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and cytotoxicity o the substances were analyzed. Results: Three ethanolic extracts of Penicillium sp., Cladosporium (001), and Cladosporium (002) exhibited the greatest inhibition halos in sensitive and resistant strains of E. coli and S. aureus. The MIC and CBM found were statistically significant (p≤0.05) compared with the gentamicin control. Furthermore, the cytotoxicity test results of CC50>1,000 demonstrated that the endophytic fungi studied exhibit bactericidal characteristics without causing unintended damage. Conclusion: The endophytic fungi M. oleifera and M. americana represent a source of active secondary metabolites with antimicrobial and non-toxic properties. In light of these findings, further research should proceed with chemical identification of the compounds and the study of their mechanisms of action, especially given the paucity of current scientific knowledge concerning the isolation of endophytes in these plants.


Assuntos
Antibacterianos/isolamento & purificação , Endófitos/fisiologia , Fungos/fisiologia , Mammea/microbiologia , Moringa oleifera/microbiologia , Plantas Medicinais/microbiologia , Animais , Antibacterianos/farmacologia , Chlorocebus aethiops , Cladosporium/química , Cladosporium/isolamento & purificação , Cladosporium/fisiologia , Avaliação Pré-Clínica de Medicamentos , Farmacorresistência Bacteriana Múltipla , Endófitos/isolamento & purificação , Escherichia coli/efeitos dos fármacos , Etanol , Fungos/isolamento & purificação , Testes de Sensibilidade Microbiana , Penicillium/química , Penicillium/isolamento & purificação , Penicillium/fisiologia , Folhas de Planta/microbiologia , Caules de Planta/microbiologia , Sementes/microbiologia , Staphylococcus aureus/efeitos dos fármacos , Células Vero
9.
Int J Mol Sci ; 21(3)2020 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-32033175

RESUMO

In the United Arab Emirates (UAE), royal poinciana (Delonix regia) trees suffer from stem canker disease. Symptoms of stem canker can be characterized by branch and leaf dryness, bark lesions, discoloration of xylem tissues, longitudinal wood necrosis and extensive gumming. General dieback signs were also observed leading to complete defoliation of leaves and ultimately death of trees in advanced stages. The fungus, Neoscytalidium dimidiatum DSM 109897, was consistently recovered from diseased royal poinciana tissues; this was confirmed by the molecular, structural and morphological studies. Phylogenetic analyses of the translation elongation factor 1-a (TEF1-α) of N. dimidiatum from the UAE with reference specimens of Botryosphaeriaceae family validated the identity of the pathogen. To manage the disease, the chemical fungicides, Protifert®, Cidely® Top and Amistrar® Top, significantly inhibited mycelial growth and reduced conidial numbers of N. dimidiatum in laboratory and greenhouse experiments. The described "apple bioassay" is an innovative approach that can be useful when performing fungicide treatment studies. Under field conditions, Cidely® Top proved to be the most effective fungicide against N. dimidiatum among all tested treatments. Our data suggest that the causal agent of stem canker disease on royal poinciana in the UAE is N. dimidiatum.


Assuntos
Ascomicetos/genética , Fabaceae/microbiologia , Doenças das Plantas/microbiologia , Doenças das Plantas/terapia , Caules de Planta/microbiologia , Ascomicetos/efeitos dos fármacos , Fungicidas Industriais/farmacologia , Fator 1 de Elongação de Peptídeos/genética , Filogenia , Emirados Árabes Unidos , Madeira/microbiologia
10.
J Agric Food Chem ; 68(9): 2607-2614, 2020 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-32096642

RESUMO

Fused-ring aromatics, important skeletal components of black carbon (BC), contribute to long-term carbon (C) sequestration in nature. They have previously been thought to be primarily formed by incomplete combustion of organic materials, whereas the nonpyrogenic origins are negligible. Using advanced solid-state 13C nuclear magnetic resonance (NMR), including recoupled long-range C-H dipolar dephasing, exchange with protonated and nonprotonated spectral editing (EXPANSE), and dipolar-dephased double-quantum/single-quantum (DQ/SQ) spectroscopy, we for the first time identify fused-ring aromatics that formed during the decomposition of wheat (Triticum sp.) straw in soil under aerobic, but not anaerobic conditions. The observed formation of polyaromatic units as plant litter decomposes provides direct evidence for humification. Moreover, the estimation of the annual flux of such nonpyrogenic BC could be equivalent to 3-12% of pyrogenic BC added to soils from all other sources. Our findings significantly extend the understanding of potential sources of fused-ring aromatic C and BC in soils as well as the global C cycle.


Assuntos
Triticum/química , Aerobiose , Bactérias/metabolismo , Biodegradação Ambiental , Caules de Planta/química , Caules de Planta/microbiologia , Microbiologia do Solo , Triticum/microbiologia
11.
Appl Microbiol Biotechnol ; 104(8): 3627-3641, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32078018

RESUMO

Plants associate with numerous microbes, but little is known about how microbiome components, especially fungi, adapt to specific plant compartments. The adaptability of microbial function to the plant compartment is also not clear especially for woody species. Here, we characterized the bacterial and fungal communities in root endosphere, stems, and rhizospheres of 33 Broussonetia papyrifera seedlings, based on amplification of 16S and ITS rRNA. Results showed that the α-diversity indexes of the bacterial community were significantly different in different plant compartments and they significantly increased from stem to root endosphere to the rhizosphere, whereas those of the fungal community were similar (p > 0.05). However, the result of constrained PCoA (CPCoA) and analysis of similarity (ANOSIM) showed that both bacterial and fungal compositions were significantly affected by plant compartments (p < 0.01). In detail, the operational taxonomic units (OTUs) distribution of the bacterial community was significantly different, but 249 of 252 fungal OTUs were shared in different plant compartments. Both the bacterial and fungal compositions were significantly influenced by plant compartments, based on the result on phyla, core OTUs, and indicator OTUs level. Further, 40 of 42 enriched KEGG pathways involving the bacteria also differed significantly among plant compartments (p < 0.01). This study provides an understanding of the influence of plant compartments on the microbiome and confirms that the disperse limitation of fungal OTUs across different plant compartments is smaller. This study sheds light on how the microbial community adapts to and thrives in different plant compartments.


Assuntos
Broussonetia/anatomia & histologia , Broussonetia/microbiologia , Microbiota , Rizosfera , Bactérias/classificação , Bactérias/metabolismo , Fungos/classificação , Fungos/fisiologia , Raízes de Plantas/microbiologia , Caules de Planta/microbiologia
12.
Int J Syst Evol Microbiol ; 70(4): 2440-2448, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32100697

RESUMO

Pectobacterium strains isolated from potato stems in Finland, Poland and the Netherlands were subjected to polyphasic analyses to characterize their genomic and phenotypic features. Phylogenetic analysis based on 382 core proteins showed that the isolates clustered closest to Pectobacterium polaris but could be divided into two clades. Average nucleotide identity (ANI) analysis revealed that the isolates in one of the clades included the P. polaris type strain, whereas the second clade was at the border of the species P. polaris with a 96 % ANI value. In silico genome-to-genome comparisons between the isolates revealed values below 70%, patristic distances based on 1294 core proteins were at the level observed between closely related Pectobacterium species, and the two groups of bacteria differed in genome size, G+C content and results of amplified fragment length polymorphism and Biolog analyses. Comparisons between the genomes revealed that the isolates of the atypical group contained SPI-1-type Type III secretion island and genes coding for proteins known for toxic effects on nematodes or insects, and lacked many genes coding for previously characterized virulence determinants affecting rotting of plant tissue by soft rot bacteria. Furthermore, the atypical isolates could be differentiated from P. polaris by their low virulence, production of antibacterial metabolites and a citrate-negative phenotype. Based on the results of a polyphasic approach including genome-to-genome comparisons, biochemical and virulence assays, presented in this report, we propose delineation of the atypical isolates as a novel species Pectobacterium parvum, for which the isolate s0421T (CFBP 8630T=LMG 30828T) is suggested as a type strain.


Assuntos
Pectobacterium/classificação , Filogenia , Solanum tuberosum/microbiologia , Sistemas de Secreção Tipo III , Análise do Polimorfismo de Comprimento de Fragmentos Amplificados , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Finlândia , Países Baixos , Pectobacterium/isolamento & purificação , Doenças das Plantas/microbiologia , Caules de Planta/microbiologia , Polônia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Virulência
13.
Theor Appl Genet ; 133(4): 1201-1212, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31974667

RESUMO

KEY MESSAGE: A total of 33 additive stem rot QTLs were identified in peanut genome with nine of them consistently detected in multiple years or locations. And 12 pairs of epistatic QTLs were firstly reported for peanut stem rot disease. Stem rot in peanut (Arachis hypogaea) is caused by the Sclerotium rolfsii and can result in great economic loss during production. In this study, a recombinant inbred line population from the cross between NC 3033 (stem rot resistant) and Tifrunner (stem rot susceptible) that consists of 156 lines was genotyped by using 58 K peanut single nucleotide polymorphism (SNP) array and phenotyped for stem rot resistance at multiple locations and in multiple years. A linkage map consisting of 1451 SNPs and 73 simple sequence repeat (SSR) markers was constructed. A total of 33 additive quantitative trait loci (QTLs) for stem rot resistance were detected, and six of them with phenotypic variance explained of over 10% (qSR.A01-2, qSR.A01-5, qSR.A05/B05-1, qSR.A05/B05-2, qSR.A07/B07-1 and qSR.B05-1) can be consistently detected in multiple years or locations. Besides, 12 pairs of QTLs with epistatic (additive × additive) interaction were identified. An additive QTL qSR.A01-2 also with an epistatic effect interacted with a novel locus qSR.B07_1-1 to affect the percentage of asymptomatic plants in a row. A total of 193 candidate genes within 38 stem rot QTLs intervals were annotated with functions of biotic stress resistance such as chitinase, ethylene-responsive transcription factors and pathogenesis-related proteins. The identified stem rot resistance QTLs, candidate genes, along with the associated SNP markers in this study, will benefit peanut molecular breeding programs for improving stem rot resistance.


Assuntos
Arachis/genética , Mapeamento Cromossômico , Resistência à Doença/genética , Epistasia Genética , Genes de Plantas , Doenças das Plantas/genética , Caules de Planta/microbiologia , Locos de Características Quantitativas/genética , Ascomicetos/fisiologia , Ligação Genética , Fenótipo , Doenças das Plantas/microbiologia
14.
Curr Microbiol ; 77(5): 746-754, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31915985

RESUMO

Arctium lappa L. is widely used for medicinal purposes across China, and significant effort has been directed toward enhancing its quality. Association with microorganisms has been shown to influence both plant growth and metabolites, providing a possible avenue for its quality improvement. In this study, we investigated the microorganism compositions of the root, stem, leaf, fruit and rhizospheric soil of A. lappa through high-throughput Illumina sequencing of 16S rRNA genes and ITS regions. A total of 796,891 16S rRNA and 626,270 ITS reads were obtained from the samples. Analysis of the sequencing data revealed that bacterial and fungal communities were more diverse in the rhizospheric soil sample compared with other samples. Cyanobacteria, Actinobacteria, Proteobacteria, Firmicutes, and Bacteroidetes phyla were found in all samples. Cyanobacteria was particularly enriched in the root, stem, leaf and fruit at 88.59%, 86.15%, 98.31% and 93.57%, respectively; Actinobacteria was the highest in rhizospheric soil, at 37.53%. Ascomycota was the most dominant fungal phylum, representing 69.17%, 58.18%, 87.93%, 90.18% and 80.21% in the root, stem, leaf, fruit, and rhizospheric soil, respectively. Several novel unclassifiable bacterial and fungal species were also detected. In total, we detected about 922 bacterial and 334 fungal species, which include a number of unclassifiable species. Additionally, the root, stem, leaf, fruit and rhizospheric soil of A. lappa were sources for screening new bioactive metabolites.


Assuntos
Arctium/microbiologia , Microbiota , Rizosfera , Microbiologia do Solo , Ascomicetos/classificação , Bactérias/classificação , DNA Bacteriano/genética , DNA Fúngico/genética , Frutas/microbiologia , Folhas de Planta/microbiologia , Raízes de Plantas/microbiologia , Caules de Planta/microbiologia , RNA Ribossômico 16S/genética
15.
Int Microbiol ; 23(2): 345-354, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31823202

RESUMO

Endophytes have been shown to play a crucial role in determining the fitness of host plant during their association, yet the cross-functional effect of endophytes of one plant on another plant remains largely uncharacterized. In this study, we attempt to analyze the effect of native endophytes of Coleus forskohlii (Phialemoniopsis cornearis (SF1), Macrophomina pseudophaseolina (SF2), and Fusarium redolens (RF1), isolated from stem and root parts) on plant growth and secondary metabolite enhancement in medicinal plant Andrographis paniculata, and aromatic plants Pelargonium graveolens and Artemisia pallens. Here, we report, endophytic treatments with SF2 (21%) and RF1 (9%) in A. paniculata resulted in significant enhancement of andrographolide along with plant primary productivity. Correspondingly, application of fungal endophytes RF1, SF1, and SF2 significantly improved the plant growth (11 to 40%), shoot weight (28 to 34%), oil content (44 to 58%), and oil yield (72 to 122%) in P. graveolens. Interestingly, treatment of A. pallens with three fungal endophytes resulted in significant enhancement of plant productivity and oil content (12 to 80%) and oil yield (32 to 139%). Subsequently, the endophyte treatments RF1 and SF1 enhanced davanone (13 to 22%) and ethyl cinnamate (11 to 22%) content. However, SF2 endophyte-treated plants did not show any improvement in ethyl cinnamate content but enhanced the content of davanone (10%), a signature component of davana essential oil. Overall, results depict cross-functional role of native endophytes of C. forskohlii and repurposing of functional endophytes for sustainable cultivation of economically important medicinal and aromatic crops.


Assuntos
Endófitos/metabolismo , Plectranthus/microbiologia , Ascomicetos/isolamento & purificação , Ascomicetos/metabolismo , Diterpenos/metabolismo , Fusarium/isolamento & purificação , Fusarium/metabolismo , Interações entre Hospedeiro e Microrganismos , Raízes de Plantas/metabolismo , Raízes de Plantas/microbiologia , Caules de Planta/metabolismo , Caules de Planta/microbiologia , Plantas/metabolismo , Plantas/microbiologia , Plantas Medicinais/metabolismo , Plantas Medicinais/microbiologia , Plectranthus/crescimento & desenvolvimento , Plectranthus/metabolismo , Metabolismo Secundário , Sesquiterpenos/metabolismo
16.
New Phytol ; 225(2): 913-929, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31513293

RESUMO

Fusaric acid (FSA) is a phytotoxin produced by several Fusarium species and has been associated with plant disease development, although its role is still not well understood. Mutation of key genes in the FSA biosynthetic gene (FUB) cluster in Fusarium oxysporum f. sp. cubense tropical race 4 (Foc TR4) reduced the FSA production, and resulted in decreased disease symptoms and reduced fungal biomass in the host banana plants. When pretreated with FSA, both banana leaves and pseudostems exhibited increased sensitivity to Foc TR4 invasion. Banana embryogenic cell suspensions (ECSs) treated with FSA exhibited a lower rate of O2 uptake, loss of mitochondrial membrane potential, increased reactive oxygen species (ROS) accumulation, and greater nuclear condensation and cell death. Consistently, transcriptomic analysis of FSA-treated ECSs showed that FSA may induce plant cell death through regulating the expression of genes involved in mitochondrial functions. The results herein demonstrated that the FSA from Foc TR4 functions as a positive virulence factor and acts at the early stage of the disease development before the appearance of the fungal hyphae in the infected tissues.


Assuntos
Ácido Fusárico/farmacologia , Fusarium/patogenicidade , Musa/microbiologia , Apoptose/efeitos dos fármacos , Vias Biossintéticas/efeitos dos fármacos , Vias Biossintéticas/genética , Morte Celular/efeitos dos fármacos , Ácido Fusárico/biossíntese , Fusarium/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Modelos Biológicos , Família Multigênica , Fenótipo , Filogenia , Caules de Planta/microbiologia , Protoplastos/efeitos dos fármacos , Protoplastos/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Virulência/efeitos dos fármacos
17.
Funct Integr Genomics ; 20(2): 237-243, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31482368

RESUMO

Leifsonia sp. ku-ls is an endophytic bacterial strain colonizing in high numbers the stem and leaf of the high-yielding and widely grown indica rice cultivar RP Bio-226. Whole genome sequencing of this strain using Illumina Hiseq-2500 system resulted in generation of 10,103,994 paired-end reads of 150 nucleotides length. De novo assembly of the reads with A5MySeq resulted in 51 scaffolds. Kmer analysis with KAT estimated the genome size as 3.83 Mbp with 70% GC content. Annotation of the genome resulted in identification of 3930 protein-coding genes, 45 tRNA genes, and 3 rRNA genes. Detailed analysis of the genes predicted resulted in identification of host beneficial genes which include genes associated with hormone production, nitrogen metabolism, and stress response. There is an elaborate defense against oxidative stress present in this bacterium which also can mitigate plant oxidative stress resulting from disease/abiotic stress. Comparison of this endophytic bacterial genome with non-endophytic Leifsonia sp. showed presence of additional genes, increase in copy number of some of the genes and regulators. Many genes with eukaryotic-like domains have also been identified in this bacterium.


Assuntos
Micrococcaceae/genética , Oryza/microbiologia , Sequenciamento Completo do Genoma , Biblioteca Gênica , Genoma Bacteriano , Estresse Oxidativo , Folhas de Planta/microbiologia , Caules de Planta/microbiologia , RNA Ribossômico/genética , RNA de Transferência/genética , Espécies Reativas de Oxigênio
18.
Theor Appl Genet ; 133(1): 259-270, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31637459

RESUMO

KEY MESSAGE: The widely deployed, oat stem rust resistance gene Pg13 was mapped by linkage analysis and association mapping, and KASP markers were developed for marker-assisted selection in breeding programs. Pg13 is one of the most extensively deployed stem rust resistance genes in North American oat cultivars. Identification of markers tightly linked to this gene will be useful for routine marker-assisted selection, identification of gene pyramids, and retention of the gene in backcrosses and three-way crosses. To this end, high-density linkage maps were constructed in four bi-parental mapping populations using SNP markers identified from 6K oat Infinium iSelect and genotyping-by-sequencing platforms. Additionally, genome-wide associations were identified using two sets of association panels consisting of diverse elite oat lines in one set and landrace accessions in the other. The results showed that Pg13 was located at approximately 67.7 cM on linkage group Mrg18 of the consensus genetic map. The gene co-segregated with the 7C-17A translocation breakpoint and with crown rust resistance gene Pc91. Co-segregating markers with the best prediction accuracy were identified at 67.7-68.5 cM on Mrg18. KASP assays were developed for linked SNP loci for use in oat breeding.


Assuntos
Avena/genética , Avena/microbiologia , Basidiomycota/fisiologia , Mapeamento Cromossômico , Resistência à Doença/genética , Genes de Plantas , Doenças das Plantas/genética , Caules de Planta/microbiologia , Segregação de Cromossomos/genética , Estudos de Associação Genética , Marcadores Genéticos , Haplótipos/genética , Doenças das Plantas/microbiologia , Caules de Planta/genética , Polimorfismo de Nucleotídeo Único/genética
19.
Plant Dis ; 103(12): 3218-3225, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31596688

RESUMO

Basal stem rot (BSR), caused by the Ganoderma fungus, is an infectious disease that affects oil palm (Elaeis guineensis) plantations. BSR leads to a significant economic loss and reductions in yields of up to Malaysian Ringgit (RM) 1.5 billion (US$400 million) yearly. By 2020, the disease may affect ∼1.7 million tonnes of fresh fruit bunches. The plants appear symptomless in the early stages of infection, although most plants die after they are infected. Thus, early, accurate, and nondestructive disease detection is crucial to control the impact of the disease on yields. Terrestrial laser scanning (TLS) is an active remote-sensing, noncontact, cost-effective, precise, and user-friendly method. Through high-resolution scanning of a tree's dimension and morphology, TLS offers an accurate indicator for health and development. This study proposes an efficient image processing technique using point clouds obtained from TLS ground input data. A total of 40 samples (10 samples for each severity level) of oil palm trees were collected from 9-year-old trees using a ground-based laser scanner. Each tree was scanned four times at a distance of 1.5 m. The recorded laser scans were synched and merged to create a cluster of point clouds. An overhead two-dimensional image of the oil palm tree canopy was used to analyze three canopy architectures in terms of the number of pixels inside the crown (crown pixel), the degree of angle between fronds (frond angle), and the number of fronds (frond number). The results show that the crown pixel, frond angle, and frond number are significantly related and that the BSR severity levels are highly correlated (R2 = 0.76, P < 0.0001; R2 = 0.96, P < 0.0001; and R2 = 0.97, P < 0.0001, respectively). Analysis of variance followed post hoc tests by Student-Newman-Keuls (Newman-Keuls) and Dunnett for frond number presented the best results and showed that all levels were significantly different at a 5% significance level. Therefore, the earliest stage that a Ganoderma infection could be detected was mildly infected (T1). For frond angle, all post hoc tests showed consistent results, and all levels were significantly separated except for T0 and T1. By using the crown pixel parameter, healthy trees (T0) were separated from unhealthy trees (moderate infection [T2] and severe infection [T3]), although there was still some overlap with T1. Thus, Ganoderma infection could be detected as early as the T2 level by using the crown pixel and the frond angle parameters. It is hard to differentiate between T0 and T1, because during mild infection, the symptoms are highly similar. Meanwhile, T2 and T3 were placed in the same group, because they showed the same trend. This study demonstrates that the TLS is useful for detecting low-level infection as early as T1 (mild severity). TLS proved beneficial in managing oil palm plantation disease.


Assuntos
Arecaceae , Ganoderma , Arecaceae/microbiologia , Ganoderma/fisiologia , Lasers , Caules de Planta/microbiologia , Tecnologia de Sensoriamento Remoto
20.
Microb Pathog ; 136: 103713, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31491553

RESUMO

Forty-five bacterial isolates recovered from surface-sterilized root, stem and leaf tissues of tomato were studied for their antifungal activity against phytopathogens, and plant growth-promoting (PGP) and biocontrol traits. Six plant-associated bacteria suppressed all the pathogens tested under in vitro plate assay and also shown PGP and biocontrol traits. The six isolates showing PGP and biocontrol properties were identified as Bacillus spp., based on the microbial identification system (Biolog) and partial sequence analysis of 16S rDNA. Two independent field trials were conducted with biocontrol bacteria along with chemical control (Thiram+Fytolan) and control (Without treatment). The averaged results of two field trails revealed that tomato plants inoculated with BETS11 (11.73 t/ha) and BETR11 (11.24 t/ha) strains showed significantly higher yield and disease reduction on par with chemical control (11.81 t/ha). However, there was an increase in the yield with respect to uninoculated control except the isolate BETS5 (9.09 t/ha). Therefore, the isolates BETS11 and BETR11 may be used as efficient biofertilizer and bio-control agent for tomato production in the Island agricultural ecosystem.


Assuntos
Antifúngicos/metabolismo , Bactérias/metabolismo , Lycopersicon esculentum/crescimento & desenvolvimento , Lycopersicon esculentum/microbiologia , Reguladores de Crescimento de Planta/metabolismo , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Análise por Conglomerados , DNA Ribossômico/química , DNA Ribossômico/genética , Controle Biológico de Vetores , Filogenia , Doenças das Plantas/prevenção & controle , Folhas de Planta/microbiologia , Raízes de Plantas/microbiologia , Caules de Planta/microbiologia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
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