Redefining the Genus Corollospora Based on Morphological and Phylogenetic Approaches

The present study, initially to resolve the cryptic species within Corollospora maritima, is to determine how to attain taxonomic discrimination at species and generic levels. Multiple sequence alignments (MSAs) of the ITS, 28S, and 18S regions of the nuclear ribosomal cistron were separately subjected to pairwise distance assessments, Bayesian, and Maximum likelihood phylogenetic analyses. Morphological descriptions of 15 type strains of Corollospora species, along with MSAs involving representatives of the whole genus Corollospora (268 isolates, many from C. maritima sensu lato) totaling 355 published sequences, allowed phylogenetic assessments conducted to the following p-distance thresholds in the ITS/28S regions: ≥3%/1% for species segregation and ≥8%/2% for generic segregation. This resulted in the introduction of 10 new genera encompassing 13 new combinations of current Corollospora species: Ajigaurospora pseudopulchella, Corollosporella anglusa, Corollosporella ramulosa, Corollosporopsis portsaidica, Garethelia parvula, Honshuriella fusca, Keraliethelia pulcehlla, Nakagariella filiformis, Paracorollospora angusta, Paracorollospora luteola, Paracorollospora marina, Shirahamella gracilis, and Tokuratelia colossa. Furthermore, seven undefined genera considered putative new genera (pNGenus A to G), and 16 undefined putative new species (seven spp. come from the resolution of the C. maritima complex), await re-assessment of their morphology and additional molecular data, which may result in the recognition of new taxa.info:eu-repo/semantics/publishedVersio

Assessment of the presence of Hepatitis E virus in surface water and drinking water in Portugal

© 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).Hepatitis E virus (HEV) is a non-enveloped single-stranded positive-sense RNA virus, belonging to the Hepeviridae family, resistant to environmental conditions, and transmitted by the consumption of contaminated water. This virus is responsible for both sporadic and epidemic outbreaks, leading to thousands of infections per year in several countries, and is thus considered an emerging disease in Europe and Asia. This study refers to a survey in Portugal during 2019, targeting the detection and eventual quantification of enteric viruses in samples from surface and drinking water. Samples positive for HEV RNA were recurrently found by reverse transcription quantitative PCR (RT-qPCR), in both types of matrix. The infectivity of these samples was evaluated in cultured Vero E6 cells and RNA from putative viruses produced in cultures evidencing cytopathic effects and was subjected to RT-qPCR targeting HEV genomic RNA. Our results evidenced the existence of samples positive either for HEV RNA (77.8% in surface water and 66.7% in drinking water) or for infectious HEV (23.0% in surface water and 27.7% in drinking water). These results highlight the need for effective virological control of water for human consumption and activities.This research was funded by Empresa Portuguesa das Águas Livres (EPAL) and Foundation for Science and Technology (FCT) Portugal through a Ph.D. grant to D. Salvador (PDE/BDE/114582/2016) and FCT/MCTES projects UIDP/50017/2020+UIDB/50017/2020 and UIDB/04295/2020 through national funds.info:eu-repo/semantics/publishedVersio

Does Arbuscular Mycorrhiza Determine Soil Microbial Functionality in Nutrient-Limited Mediterranean Arid Ecosystems?

Arbuscular mycorrhizal fungi (AMF) are determinant for the performance of plant communities and for the functionality of terrestrial ecosystems. In natural ecosystems, grazing can have a major impact on mycorrhizal fungi and consequently on plant growth. The objective of this study was to evaluate the statements referred above in Mediterranean arid areas in Tunisia. Root samples and rhizosphere soils of five dominant herbaceous plants were studied at six distinct arid sites differing on soil proprieties and grazing intensity. At each site, chemical and dynamic properties of the soil were characterized as well as the AMF colonization intensity and the soil functionality. Results showed that the mycorrhizal frequency and intensity and spore density, varied between plants in the same site and, for each plant, between sites and evidenced a positive effect of mycorrhized plants on soil microbial activity. Grazing and soil properties strongly affected AMF composition and the soil microbial and biochemical dynamics, which presented the lowest values at the sites with the highest grazing intensities. In conclusion, these results demonstrate that AMF improve soil biological properties, supporting the hypothesis that mycorrhiza and grazing compete for plant photosynthates, and highlight the importance of mycorrhizal symbiosis towards soil functionality under arid conditions.info:eu-repo/semantics/publishedVersio

Arbuscular mycorrhizal fungi in soil, roots and rhizosphere of Medicago truncatula: diversity and heterogeneity under semi-arid conditions

Mycorrhizal symbioses are considered indicators of ecosystem biodiversity. However, their diversity and relevance in arid and semi-arid ecosystems are poorly understood. This study addressed this subject, the main objective being to evaluate arbuscular mycorrhizal fungi (AMF) diversity and heterogeneity in a semi-arid region. Samples of bulk and rhizosphere soil and fine roots of Medicago truncatula were collected at four different sites with the same aridity index (6.1), in Bou-Hedma National Park, Tunisia, a semi-arid ecosystem. AMF taxa were assessed by 454- pyrosequencing and identified by BLAST matching of operational taxonomic units (OTUs) against the MaarjAM database, targeting AMF SSU rRNA gene diversity. Roots were the hotspots of AMF diversity (107 OTUs out of a total of 138). Of the 138 OTUs, 113 found correspondence in the MaarjAM database, with 32 AMF virtual taxa (VTX),19 Site-exclusive (SE) and 13 common to at least two sites (Non-site exclusive, NSE); the remaining 25 OTUs grouped in 16 putative new AMF taxa (pNTX), each one consisting of OTUs sharing pairwise distances not higher than 3%. We found a high diversity and heterogeneity of AMF across the four sites, which showed, in a regression analysis, significant relation to six out of the eight environmental parameters evaluated: grazing activity and soil texture, electrical conductivity, organic matter, total phosphorus and total nitrogen. AMF colonization of plants also presented significant differences among the four sites, as well as spore density, microbial biomass and several enzymatic activities (dehydrogenase, β-glucosidase and phosphatase) evaluated in rhizosphere soils. The four sites clustered in two groups in a hierarchical clustering evaluation based on their AMF diversity (total numbers of OTU, VTX and pNTX) and the parameters referred above. The crucial role of abiotic factors, other than aridity index, on AMF community composition, was evidenced by the high heterogeneity found between AMF communities across sites under identical aridity conditions

Gymnodinium catenatum Graham isolated from the Portuguese coast: Toxin content and genetic characterization

The bloom forming marine dinoflagellate Gymnodinium catenatum Graham has been linked to paralytic shellfish poisoning (PSP) outbreaks in humans. Along the Portuguese coast (NE Atlantic), G. catenatum shows a complex bloom pattern, raising questions about the origin and affinities of each bloom population. In this work, the variability within six cultured strains of G. catenatum isolated from Portuguese coastal waters (S coast, W coast and NW coast), between 1999 and 2011, was investigated. The strains were analyzed for toxin profiling and intra-specific genetic diversity. Regarding the toxin profile, differences recorded between strains could not be assigned to the time of isolation or geographical origin. The parameter that most influenced the toxin profile was the life-cycle stage that originated the culture: vegetative cell versus hypnozygote (resting cyst). At the genetic level, all strains showed similar sequences for the D1-D2 region of the large subunit (LSU) of the nuclear ribosomal DNA (rDNA) and shared complete identity with strains from Spain, Algeria, China and Australia. Conversely, we did not find a total identity match for the ITS-5.8S nuclear rDNA fragment. After sequence analysis, two guanine/adenine (R) single nucleotide polymorphisms (SNP 1 and 2) were detected for all strains, in the ITS1 region. This species has been reported to present very conservative LSU and ITS-5.8S rDNA regions, though with few SNP, including SNP1 of this study, already attributed to strains from certain locations. The SNP here described characterize G. catenatum populations from Portuguese waters and may represent valuable genetic markers for studies on the phylogeography of this species.info:eu-repo/semantics/publishedVersio

Delineation of estuarine management units: evaluation of an automatic procedure

info:eu-repo/semantics/publishedVersio

Vaccinia Virus Mutants with Alanine Substitutions in the Conserved G5R Gene Fail To Initiate Morphogenesis at the Nonpermissive Temperature

The initial characterization of the product of the vaccinia virus G5R gene, which is conserved in all poxviruses sequenced to date, is described. The G5 protein was detected in the core fraction of purified virions, and transcription and translation of the G5R open reading frame occurred early in infection, independently of DNA replication. Attempts to delete the G5R gene and isolate a replication-competent virus were unsuccessful, suggesting that G5R encodes an essential function. We engineered vaccinia virus mutants with clusters of charged amino acids changed to alanines and determined that several were unable to replicate at 40°C but grew well at 37°C. At the nonpermissive temperature, viral gene expression and DNA replication and processing were unperturbed. However, tyrosine phosphorylation and proteolytic cleavage of the A17 membrane protein and proteolytic cleavage of core proteins were inhibited at 40°C, suggesting an assembly defect. The cytoplasm of cells that had been infected at the nonpermissive temperature contained large granular areas devoid of cellular organelles or virus structures except for occasional short crescent-shaped membranes and electron-dense lacy structures. The temperature-sensitive phenotype of the G5R mutants closely resembled the phenotypes of vaccinia virus mutants carrying conditionally lethal F10R protein kinase and H5R mutations. F10, although required for phosphorylation of A17 and viral membrane formation, was synthesized by the G5R mutants under nonpermissive conditions. An intriguing possibility is that G5 participates in the formation of viral membranes, a poorly understood event in poxvirus assembly

Arbuscular mycorrhizal traits are good indicators of soil multifunctionality in drylands

Drylands are highly susceptible to degradation and climate change, which has important ecological and socio- economic consequences worldwide. To halt drylands degradation, plant species selection for restoration is starting to include also a functional approach, but does not integrate belowground functional traits yet. Therefore we tested the use of mycorrhizal traits to identify native plant species which host guilds of beneficial microbes and therefore enhance multiple soil functions simultaneously – soil multifunctionality. We used a soil organic matter (SOM) gradient (0.9–1.9%) and evaluated the effect of 14 common and abundant native herbaceous plant species (+bare soil) on soil functionality. We measured several soil functions (soil microbial biomass, metabolic quotient, and enzymatic activities – dehydrogenase, β-glucosidase and phosphatase) and built a soil multi- functionality index. Soil multifunctionality was strongly associated with mycorrhizal traits across the analysed SOM gradient. Bare soils and soils under non- or low-mycorrhizal plant species displayed the lower soil func- tionality (both individual functions and multifunctionality), while soils under Fabaceae species (Medicago truncatula, Astragalus corrugatus and Lotus halophilus) displayed the highest. For each plant species, the highest soil multifunctionality was observed at the SOM-richer site. Soil multifunctionality was strongly associated with all the mycorrhizal traits but mycorrhizal intensity and AMF spores abundance were more correlated with soil multifunctionality than mycorrhizal frequency. Our data show that: i) AM traits can be good indicators of simultaneous multiple soil functions in drylands; and ii) soil multifunctionality in drylands can be improved by management practices promoting SOM accumulation and favouring specific native plant species.info:eu-repo/semantics/publishedVersio

Assessing heavy metal contamination in Sado Estuary

The Sado Estuary in Portugal is a good example of a site where human pressures and ecological values collide with each other. An overall contamination assessment has never been conducted in a way that is comprehensible to estuary managers. One of the aims of this work was to select different types of index to aggregate and assess heavy metal contamination in the Sado Estuary in an accessible manner. Another aim was to use interpolation surfaces per metal to compare and gauge the results of the indices and to assess the contamination separately per metal. Seventy-eight stations were sampled within the main bay of the estuary and a set of heavy metals and metalloids was established, Cd, Cu, Pb, Cr, Hg, Al, Zn and As. The sediment fine fraction content, organic matter and redox potential were also analysed. Various indices for contamination, background enrichment and ecological risk were used, tested, compared and performance-evaluated. All metals and metalloids were strongly correlated, and the indices appear to reflect heavy metal variability satisfactorily. Difficulties were found in some indices regarding boundary definition (minimum and maximum) and comparability with other estuaries, thus better methods of standardization should be a priority issue. According to the index that has the highest performance score within the group of ecological risk indices – the Sediment Quality Guideline Quotient – only 3% of the stations are highly contaminated and register a high potential for observing adverse biological effects, whereas 47% display moderate contamination. This index can be complemented with the contamination index, which allows more site-specific and accurate information on contaminant levels. If the aim of work on contamination evaluation is to assess the overall contamination of a study area, the indices are highly appropriate. For spatial and source evaluation per metal, interpolation surfaces should also be used