Bacillus megaterium: bacteria endofítica de callos de Ilex paraguariensis con actividad de promoción del crecimiento

Los microorganismos endófitos viven dentro de plantas sanas y su aislamiento e identificación pueden favorecer las aplicaciones biotecnológicas. Los microorganismos endofíticos fueron encontrados en callos de Ilex paraguariensis cultivados in vitro durante cinco meses. Se usó la secuenciación de la región 16S rRNA para identificar dos aislados como Bacillus megaterium. La presencia de células bacterianas en los espacios intercelulares de los cultivos de callos se detectó mediante análisis ultraestructurales. Los aislamientos también se evaluaron para la producción de ácido indol acético (AIA) y su potencial en la promoción del crecimiento de las plántulas de Phaseolus vulgaris L. La síntesis de ácido AIA en presencia y ausencia de L-triptófano se detectó por análisis colorimétrico para ambos aislamientos. En presencia de extractos de las cepas IPC06 e IPC07, las plántulas de P. vulgaris crecieron más rápido en comparación con las plantas control sin el extracto en pruebas in vitro.Palabras clave: yerba mate, 16S rRNA, secuenciación, cultivo de tejido

Viral diversity in oral cavity from Sapajus nigritus by metagenomic analyses

Sapajus nigritus are non-human primates which are widespread in South America. They are omnivores and live in troops of up to 40 individuals. The oral cavity is one of the main entry routes for microorganisms, including viruses. Our study proposed the identification of viral sequences from oral swabs collected in a group of capuchin monkeys (n = 5) living in a public park in a fragment of Mata Atlantica in South Brazil. Samples were submitted to nucleic acid extraction and enrichment, which was followed by the construction of libraries. After high-throughput sequencing and contig assembly, we used a pipeline to identify 11 viral families, which are Herpesviridae, Parvoviridae, Papillomaviridae, Polyomaviridae, Caulimoviridae, Iridoviridae, Astroviridae, Poxviridae, and Baculoviridae, in addition to two complete viral genomes of Anelloviridae and Genomoviridae. Some of these viruses were closely related to known viruses, while other fragments are more distantly related, with 50% of identity or less to the currently available virus sequences in databases. In addition to host-related viruses, insect and small vertebrate-related viruses were also found, as well as plant-related viruses, bringing insights about their diet. In conclusion, this viral metagenomic analysis reveals, for the first time, the profile of viruses in the oral cavity of wild, free ranging capuchin monkeys

Human rhinovirus spatial-temporal epidemiology in rural coastal Kenya, 2015-2016, observed through outpatient surveillance

Background Human rhinovirus (HRV) is the predominant cause of upper respiratory tract infections, resulting in a significant public health burden. The virus circulates as many different types (~160), each generating strong homologous, but weak heterotypic, immunity. The influence of these features on transmission patterns of HRV in the community is understudied. Methods Nasopharyngeal swabs were collected from patients with symptoms of acute respiratory infection (ARI) at nine out-patient facilities across a Health and Demographic Surveillance System between December 2015 and November 2016. HRV was diagnosed by real-time RT-PCR, and the VP4/VP2 genomic region of the positive samples sequenced. Phylogenetic analysis was used to determine the HRV types. Classification models and G-test statistic were used to investigate HRV type spatial distribution. Demographic characteristics and clinical features of ARI were also compared. Results Of 5,744 NPS samples collected, HRV was detected in 1057 (18.4%), of which 817 (77.3%) were successfully sequenced. HRV species A, B and C were identified in 360 (44.1%), 67 (8.2%) and 390 (47.7%) samples, respectively. In total, 87 types were determined: 39, 10 and 38 occurred within species A, B and C, respectively. HRV types presented heterogeneous temporal patterns of persistence. Spatially, identical types occurred over a wide distance at similar times, but there was statistically significant evidence for clustering of types between health facilities in close proximity or linked by major road networks. Conclusion This study records a high prevalence of HRV in out-patient presentations exhibiting high type diversity. Patterns of occurrence suggest frequent and independent community invasion of different types. Temporal differences of persistence between types may reflect variation in type-specific population immunity. Spatial patterns suggest either rapid spread or multiple invasions of the same type, but evidence of similar types amongst close health facilities, or along road systems, indicate type partitioning structured by local spread

Modern issues of sugar beet (<i>Beta vulgaris</i> L.) hybrid breeding

High efficiency of the cultivation of unfertilized sugar beet ovules and preparation of haploid regenerants (microclones) of pollinators – maintainers of О-type sterility and MS forms of the RMS 120 hybrid components has been shown. A technological method that accelerates the creation of new uniform starting material is proposed. It speeds up the breeding process two to threefold. The identification of haploid regenerants with sterile cytoplasm in initial populations is of great theoretical and practical importance for breeding, as it facilitates the production of homozygous lines with cytoplasmic male sterility and high-performance hybrids on sterile basis. As shown by molecular analysis, a single-nucleotide polymorphism never reported hitherto is present in the mitochondrial genome of the haploid plant regenerants. It allows identification of microclones as fertile and sterile forms. It has been found that DNA markers of the sugar beet mitochondrial genome belonging to the TR minisatellite family (TR1 and TR3) enable reliable enough identification of haploid microclonal plants as MSor O-type forms. Fragments of 1000 bp in length have been detected in monogenic forms in the analysis of 11 sugar beet plants cultured in vitro by PCR with the OP-S4 random RAPD primer. Testing of the OP-S4 marker’s being in the same linkage group as the genes responsible for expression of the economically valuable trait monogermity demonstrates its relative reliability. By the proposed method, dihaploid lines (DH) of the male-sterile form and the О-type sterility maintainer of the RMS 120 sugar beet hybrid have been obtained in in vitro culture. These lines are highly uniform in biomorphological traits, as proven under field conditions

Evolutionary history of arbuscular mycorrhizal fungi and genomic signatures of obligate symbiosis

Background The colonization of land and the diversification of terrestrial plants is intimately linked to the evolutionary history of their symbiotic fungal partners. Extant representatives of these fungal lineages include mutualistic plant symbionts, the arbuscular mycorrhizal (AM) fungi in Glomeromycota and fine root endophytes in Endogonales (Mucoromycota), as well as fungi with saprotrophic, pathogenic and endophytic lifestyles. These fungal groups separate into three monophyletic lineages but their evolutionary relationships remain enigmatic confounding ancestral reconstructions. Their taxonomic ranks are currently fluid.Results In this study, we recognize these three monophyletic linages as phyla, and use a balanced taxon sampling and broad taxonomic representation for phylogenomic analysis that rejects a hard polytomy and resolves Glomeromycota as sister to a clade composed of Mucoromycota and Mortierellomycota. Low copy numbers of genes associated with plant cell wall degradation could not be assigned to the transition to a plant symbiotic lifestyle but appears to be an ancestral phylogenetic signal. Both plant symbiotic lineages, Glomeromycota and Endogonales, lack numerous thiamine metabolism genes but the lack of fatty acid synthesis genes is specific to AM fungi. Many genes previously thought to be missing specifically in Glomeromycota are either missing in all analyzed phyla, or in some cases, are actually present in some of the analyzed AM fungal lineages, e.g. the high affinity phosphorus transporter Pho89.Conclusion Based on a broad taxon sampling of fungal genomes we present a well-supported phylogeny for AM fungi and their sister lineages. We show that among these lineages, two independent evolutionary transitions to mutualistic plant symbiosis happened in a genomic background profoundly different from that known from the emergence of ectomycorrhizal fungi in Dikarya. These results call for further reevaluation of genomic signatures associated with plant symbiosis

Beta-tubulin and Actin gene phylogeny supports Phaeoacremonium ovale as a new species from freshwater habitats in China

A new species of Phaeoacremonium, P. ovale (Togniniaceae), was isolated during a diversity study of freshwater fungi from Yunnan Province in China. Morphological and cultural studies of the fungus were carried out and its sexual and asexual morphs (holomorph) are introduced herein. This species is characterised by peculiar long-necked, semi-immersed ascomata with oval to ellipsoid ascospores and ellipsoid to ovoid conidia. Phylogenetic analyses of a combined TUB and ACT gene dataset revealed that strains of P. ovale constitute a strongly supported independent lineage and are related to P. griseo-olivaceum and P. africanum. The number of nucleotide differences, across the genes analysed, also supports establishment of P. ovale as a new species

Phylogenomics and the evolution of hemipteroid insects.

Hemipteroid insects (Paraneoptera), with over 10% of all known insect diversity, are a major component of terrestrial and aquatic ecosystems. Previous phylogenetic analyses have not consistently resolved the relationships among major hemipteroid lineages. We provide maximum likelihood-based phylogenomic analyses of a taxonomically comprehensive dataset comprising sequences of 2,395 single-copy, protein-coding genes for 193 samples of hemipteroid insects and outgroups. These analyses yield a well-supported phylogeny for hemipteroid insects. Monophyly of each of the three hemipteroid orders (Psocodea, Thysanoptera, and Hemiptera) is strongly supported, as are most relationships among suborders and families. Thysanoptera (thrips) is strongly supported as sister to Hemiptera. However, as in a recent large-scale analysis sampling all insect orders, trees from our data matrices support Psocodea (bark lice and parasitic lice) as the sister group to the holometabolous insects (those with complete metamorphosis). In contrast, four-cluster likelihood mapping of these data does not support this result. A molecular dating analysis using 23 fossil calibration points suggests hemipteroid insects began diversifying before the Carboniferous, over 365 million years ago. We also explore implications for understanding the timing of diversification, the evolution of morphological traits, and the evolution of mitochondrial genome organization. These results provide a phylogenetic framework for future studies of the group