We report here the closed and near-complete genome sequence and annotation ofBacillus velezensisstrain AGVL-005, a bacterium isolated from soybean seeds in Brazil and used for phytopathogen biocontrol.
- Publication type
- Journal Article MeSH
Fungi are considered model organisms for the analysis of important phenomena of eukaryotes. For example, some of them have been described as models to understand the phenomenon of multicellularity acquisition by different unicellular organisms phylogenetically distant. Interestingly, in this work, we describe the multicellular development in the model fungus S. reilianum. We observed that Sporisorium reilianum, a Basidiomycota cereal pathogen that at neutral pH grows with a yeast-like morphology during its saprophytic haploid stage, when incubated at acid pH grew in the form of multicellular clusters. The multicellularity observed in S. reilianum was of clonal type, where buds of "stem" cells growing as yeasts remain joined by their cell wall septa, after cytokinesis. The elaboration and analysis of a regulatory network of S. reilianum showed that the putative zinc finger transcription factor CBQ73544.1 regulates a number of genes involved in cell cycle, cellular division, signal transduction pathways, and biogenesis of cell wall. Interestingly, homologous of these genes have been found to be regulated during Saccharomyces cerevisiae multicellular growth. In adddition, some of these genes were found to be negatively regulated during multicellularity of S. reilianum. With these data, we suggest that S. reilianum is an interesting model for the study of multicellular development.
- MeSH
- Basidiomycota drug effects genetics growth & development MeSH
- Cell Division drug effects MeSH
- Cell Cycle drug effects MeSH
- Fungal Proteins genetics MeSH
- Phylogeny MeSH
- Hydrogen-Ion Concentration MeSH
- Acids pharmacology MeSH
- Signal Transduction drug effects MeSH
- Publication type
- Journal Article MeSH
The citrus black spot (CBS), caused by Phyllosticta citricarpa, is one of the most important citrus diseases in subtropical regions of Africa, Asia, Oceania, and the Americas, and fruits with CBS lesions are still subject to quarantine regulations in the European Union. Despite the high application of fungicides, the disease remains present in the citrus crops of Central and South America. In order to find alternatives to help control CBS and reduce the use of fungicides, we explored the antifungal potential of endophytic actinomycetes isolated from the Brazilian medicinal plant Vochysia divergens found in the Pantanal biome. Two different culture media and temperatures were selected to identify the most efficient conditions for the production of active secondary metabolites. The metabolites produced by strain Microbacterium sp. LGMB471 cultured in SG medium at 36 °C considerably inhibited the development of P. citricarpa. Three isoflavones and five diketopiperazines were identified, and the compounds 7-O-β-D-glucosyl-genistein and 7-O-β-D-glucosyl-daidzein showed high activity against P. citricarpa, with the MIC of 33 μg/mL and inhibited the production of asexual spores of P. citricarpa on leaves and citrus fruits. Compounds that inhibit conidia formation may be a promising alternative to reduce the use of fungicides in the control of CBS lesions, especially in regions where sexual reproduction does not occur, as in the USA. Our data suggest the use of Microbacterium sp. LGMB471 or its metabolites as an ecological alternative to be used in association with the fungicides for the control of CBS disease.
- MeSH
- Actinomycetales chemistry MeSH
- Ascomycota drug effects MeSH
- Citrus microbiology MeSH
- Diketopiperazines isolation & purification pharmacology MeSH
- Fungicides, Industrial isolation & purification pharmacology MeSH
- Isoflavones isolation & purification pharmacology MeSH
- Culture Media MeSH
- Plant Leaves microbiology MeSH
- Microbial Sensitivity Tests MeSH
- Plant Diseases microbiology MeSH
- Secondary Metabolism MeSH
- Spores, Fungal drug effects MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Asia MeSH
- Brazil MeSH
- United States MeSH
It is known that volatile emissions from some beneficial rhizosphere microorganisms promote plant growth. Here we show that volatile compounds (VCs) emitted by phylogenetically diverse rhizosphere and non-rhizhosphere bacteria and fungi (including plant pathogens and microbes that do not normally interact mutualistically with plants) promote growth and flowering of various plant species, including crops. In Arabidopsis plants exposed to VCs emitted by the phytopathogen Alternaria alternata, changes included enhancement of photosynthesis and accumulation of high levels of cytokinins (CKs) and sugars. Evidence obtained using transgenic Arabidopsis plants with altered CK status show that CKs play essential roles in this phenomenon, because growth and flowering responses to the VCs were reduced in mutants with CK-deficiency (35S:AtCKX1) or low receptor sensitivity (ahk2/3). Further, we demonstrate that the plant responses to fungal VCs are light-dependent. Transcriptomic analyses of Arabidopsis leaves exposed to A. alternata VCs revealed changes in the expression of light- and CK-responsive genes involved in photosynthesis, growth and flowering. Notably, many genes differentially expressed in plants treated with fungal VCs were also differentially expressed in plants exposed to VCs emitted by the plant growth promoting rhizobacterium Bacillus subtilis GB03, suggesting that plants react to microbial VCs through highly conserved regulatory mechanisms.
- MeSH
- Alternaria physiology MeSH
- Arabidopsis microbiology physiology MeSH
- Cytokinins physiology MeSH
- Photosynthesis physiology MeSH
- Real-Time Polymerase Chain Reaction MeSH
- Flowers growth & development physiology MeSH
- Gene Expression Regulation, Plant physiology MeSH
- Rhizosphere MeSH
- Plants microbiology MeSH
- Volatile Organic Compounds metabolism MeSH
- Transcriptome physiology MeSH
- Plant Development physiology MeSH
- Publication type
- Journal Article MeSH
In field and laboratory experiments during 2014-2017, we investigated the influence of lower and higher cultivation intensity of wheat and ecological factors (weather-temperature and rainfalls, year) on the occurrence of phytopathogenic fungi on the leaves of winter wheat. The prevailing fungi in those years were Mycosphaerella graminicola (Fuckel) J. Schrott and Pyrenophora tritici-repentis (Died.) Drechsler. Using cluster analysis, we statistically evaluated interrelationships of known factors on the abundance of the fungi on leaf surfaces. Our results showed strongest correlation with Mycosphaerella graminicola and Pyrenophora tritici-repentis abundance to be with lower cultivation intensity and year done by the temperature and the rainfalls. The two pathogens-Puccinia tritici Oerst and Hymenula cerealis Ellis & Everh. occurred only very sparsely in some years and had little positive or negative correlation with named factors. The semi-early and semi-late winter wheat varieties Matchball, Annie, Fakir, and Tobak were used for our experiments. Higher cultivation intensity had protective effect against leaf phytopathogenic fungi.
- MeSH
- Ascomycota classification genetics growth & development isolation & purification MeSH
- Basidiomycota classification genetics growth & development isolation & purification MeSH
- Ecosystem MeSH
- Plant Diseases microbiology MeSH
- Triticum microbiology MeSH
- Temperature MeSH
- Publication type
- Journal Article MeSH
The biological activity and the presence of genes sfp and ituD (surfactin and iturin A) among Bacillus strains isolated from the Amazon basin were determined. Bacillus spp. were tested for hemolytic activity and inhibition of fungal growth by agar plate assays in parallel with PCR for identification of sfp and ituD genes. All strains tested produced surface-active compounds, giving evidence by lysis of erythrocytes and emulsifying activity on mineral oil and soybean oil. These strains of Bacillus caused growth inhibition of several phytopathogenic fungi, including Fusarium spp., Aspergillus spp., and Bipolaris sorokiniana. The presence of genes ituD and sfp was confirmed by PCR and sequence analysis. The only exception was Bacillus sp. P34 that lacks sfp gene. Lipopeptides were isolated from culture supernatants and analyzed by mass spectrometry. Characteristic m/z peaks for surfactin and iturin were observed, and some strains also produced fengycin and bacillomycin. The remarkable antifungal activity showed by the strains could be associated with the co-production of three or more lipopeptide antibiotics. Screening for novel bacteria producing useful biosurfactants or biocontrol agents for agriculture is a topic of greatest importance to eliminate chemical pollutants.
- MeSH
- Acyl-Carrier Protein S-Malonyltransferase genetics MeSH
- Antifungal Agents metabolism pharmacology MeSH
- Bacillus genetics metabolism MeSH
- Bacterial Proteins genetics MeSH
- Fungi drug effects growth & development MeSH
- Lipopeptides metabolism pharmacology MeSH
- Surface-Active Agents metabolism MeSH
- Plants microbiology MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Actinomycete strain YIM PH20352, isolated from the rhizosphere soil sample of Panax notoginseng collected in WenShang, Yunnan Province, China, exhibited antifungal activity against some phytopathogenic fungi. The structures of bioactive molecules, isolated from the ethyl acetate extract of the fermentation broth of the strain, were identified as rabelomycin (1) and dehydrorabelomycin (2) based on extensive spectroscopic analyses. Compound 1 exhibited antifungal activity against four tested root-rot pathogens of the Panax notoginseng including Plectosphaerella cucumerina, Alternaria panax, Fusarium oxysporum, and Fusarium solani with the MIC values at 32, 64, 128, and 128 μg/mL, respectively. Compound 2 exhibited antifungal activity against F. oxysporum, P. cucumerina, F. solani, and A. panax with the MIC values at 64, 64, 128, and 128 μg/mL, respectively. Based on the phylogenetic analyses, the closest phylogenetic relative of strain YIM PH20352 is Streptomyces cellulosae NBRC 13027 T (AB184265) (99.88%), so strain YIM PH20352 was identified as Streptomyces cellulosae. To the best of our knowledge, this is the first report of rabelomycin and rabelomycin-type antibiotics from Streptomyces cellulosae and their antifungal activity against root-rot pathogens of the Panax notoginseng.
- MeSH
- Anthraquinones MeSH
- Antifungal Agents chemistry MeSH
- Phylogeny MeSH
- Fungi MeSH
- Plant Diseases microbiology MeSH
- Panax notoginseng * microbiology MeSH
- Soil * MeSH
- Streptomyces MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- China MeSH
The ability of Diplodia pinea to inhibit Armillaria sp., Bjerkandera adusta, Botrytis cinerea, and Rhizoctonia sp. mycelium growth was analyzed using the double-culture method. Wild-type fungal strains were incubated in a biochemical oxygen demand incubator using potato agar dextrose medium at 24 ± 2 °C for 35 days in darkness. D. pinea significantly inhibited the growth of all fungi species tested (30.75 to 98.37% inhibition) and showed moderate antagonistic activity (antagonistic index, 14.5). Chemical analysis of D. pinea culture broth extracts revealed steroids, triterpenes, and phenolic compounds. Alkaloids were qualitatively detected in the mycelium crude extract. The presence of these compounds may be related to the antagonistic activity observed. The inhibition ability of D. pinea is due to competition with the tested fungi for substrate and space.
- MeSH
- Alkaloids chemistry MeSH
- Antibiosis * MeSH
- Ascomycota growth & development physiology MeSH
- Botrytis growth & development physiology MeSH
- Culture Media chemistry MeSH
- Oxygen metabolism MeSH
- Mycelium growth & development physiology MeSH
- Plant Diseases microbiology MeSH
- Triterpenes chemistry MeSH
- Publication type
- Journal Article MeSH
The complete mitochondrial genome of the ascomycete fungus Phomopsis longicolla was sequenced using Illumina HiSeq platform. It consists of 53,439 bp with high (65.6%) A + T content and includes 14 conserved protein subunits of the mitochondrial oxidative phosphorylation system, two ribosomal RNAs and 25 tRNA genes. To our knowledge, this is the first complete mitochondrial genome of the Diaporthales member.
- MeSH
- Ascomycota genetics MeSH
- Genome Size MeSH
- Genome, Fungal MeSH
- Genome, Mitochondrial * MeSH
- Codon, Initiator MeSH
- Genes, Mitochondrial * MeSH
- Evolution, Molecular MeSH
- Gene Order * MeSH
- Sequence Analysis, DNA MeSH
- Codon, Terminator MeSH
- High-Throughput Nucleotide Sequencing MeSH
- Base Composition MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
BACKGROUND: Ixodes scapularis is the most common tick species in North America and a vector of important pathogens that cause diseases in humans and animals including Lyme disease, anaplasmosis and babesiosis. Tick defensins have been identified as a new source of antimicrobial agents with putative medical applications due to their wide-ranging antimicrobial activities. Two multigene families of defensins were previously reported in I. scapularis. The objective of the present study was to characterise the potential antimicrobial activity of two defensins from I. scapularis with emphasis on human pathogenic bacterial strains and important phytopathogenic fungi. METHODS: Scapularisin-3 and Scapularisin-6 mature peptides were chemically synthesised. In vitro antimicrobial assays were performed to test the activity of these two defensins against species of different bacterial genera including Gram-positive bacteria Staphylococcus aureus, Staphylococcus epidermidis, and Listeria spp. as well as Gram-negative bacteria Escherichia coli, Pseudomonas aeruginosa along with two plant-pathogenic fungi from the genus Fusarium. In addition, the tissue-specific expression patterns of Scapularisin-3 and Scapularisin-6 in I. scapularis midgut, salivary glands and embryo-derived cell lines were determined using PCR. Finally, tertiary structures of the two defensins were predicted and structural analyses were conducted. RESULTS: Scapularisin-6 efficiently killed L. grayi, and both Scapularisin-3 and Scapularisin-6 caused strong inhibition (IC50 value: ~1 μM) of the germination of plant-pathogenic fungi Fusarium culmorum and Fusarium graminearum. Scapularisin-6 gene expression was observed in I. scapularis salivary glands and midgut. However, Scapularisin-3 gene expression was only detected in the salivary glands. Transcripts from the two defensins were not found in the I. scapularis tick cell lines ISE6 and ISE18. CONCLUSION: Our results have two main implications. Firstly, the anti-Listeria and antifungal activities of Scapularisin-3 and Scapularisin-6 suggest that these peptides may be useful for (i) treatment of antibiotic-resistant L. grayi in humans and (ii) plant protection. Secondly, the antimicrobial properties of the two defensins described in this study may pave the way for further studies regarding pathogen invasion and innate immunity in I. scapularis.
- MeSH
- Anti-Infective Agents chemical synthesis chemistry isolation & purification pharmacology MeSH
- Defensins chemical synthesis chemistry isolation & purification pharmacology MeSH
- Fusarium drug effects MeSH
- Ixodes chemistry MeSH
- Protein Conformation MeSH
- Humans MeSH
- Listeria drug effects MeSH
- Microbial Sensitivity Tests MeSH
- Models, Molecular MeSH
- Guinea Pigs MeSH
- Staphylococcus epidermidis MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Guinea Pigs MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
