30 research outputs found
Involvement of a cinnamyl alcohol dehydrogenase of Quercus suber in the defence response to infection by Phytophthora cinnamomi
A gene encoding a potential NADPH-dependent cinnamyl alcohol dehydrogenase (QsCAD1) (GenBank accession no: AY362455) was identified in Quercus suber (cork oak). Its complete cDNA sequence was obtained by RACE-PCR, starting from total RNA extracted from roots of seedlings of Q. suber, infected with Phytophthora cinnamomi, the causal agent of the decline and sudden death of Q. suber and Quercus ilex subsp. rotundifolia in the Iberian Peninsula. Sequence information to perform the RACE-PCR
was acquired from a polymorphic fragment (C9), specifically identified by cDNA-AFLP, in leaves of epicormic shoots of a cork oak
tree that suffered sudden death. RT-PCR and hybridization analysis showed that the QsCAD1 gene is up-regulated in root seedlings
of Q. suber infected with P. cinnamomi. QsCAD1 has a high structural homology with VR-ERE (Vigna radiata), an enzyme that detoxifies eutypine (produced by Eutypa lata, the causal agent of eutypa dieback of grapevines), to eutypinol, and with
QrCAD1 (Q. ilex subsp. rotundifolia), EgCAD1 (Eucalyptus gunnii), MdCAD1 (Malus x domestica). Taken together, these results
suggest that these enzymes, and namely QsCAD1 belong to a new group of CAD potentially involved in deactivation of toxins produced by phytopathogens
Involvement of the beta-cinnamomin elicitin in infection and colonisation of cork oak roots by Phytophthora cinnamomi
The virulence of two wild type (PA45 and
PA37) and two genetically modified (13C: hygromycin resistant; FATSS: hygromycin resistant and β-cin knock-down) Phytophthora cinnamomi strains towards cork oak (Quercus suber) was assessed via a quantitative
evaluation of disease symptoms arising from a
soil infestation assay, and by a istological analysis of
root colonization. Comparison of virulence, as expressed by symptom severity, resulted in the following ranking: highly virulent (wild type strains), medium virulence (strain 13C) and weakly virulent
(FATSS). Both transgenic strains were compromised in their virulence, as expressed by symptom severity, but strain 13C was much less affected than FATSS.
Microscopic observation showed that the FATSS strain
was unable to effectively invade the root, while 13C
and the two wild type strains were all able to rapidly
colonize the whole root, including the vascular tissue.
These results strengthen the notion that elicitins are
associated, either directly or indirectly, with the
infection process of Phytophthora
A survey in natural forest ecosystems of Vietnam reveals high diversity of both new and described Phytophthora taxa including P. ramorum
In 2016 and 2017, surveys of Phytophthora diversity were performed in 25 natural and
semi-natural forest stands and 16 rivers in temperate and subtropical montane and tropical lowland
regions of Vietnam. Using baiting assays from soil samples and rivers and direct isolations from
naturally fallen leaves, 13 described species, five informally designated taxa and 21 previously
unknown taxa of Phytophthora were isolated from 58 of the 91 soil samples (63.7%) taken from the
rhizosphere of 52 of the 64 woody plant species sampled (81.3%) in 20 forest stands (83.7%), and from
all rivers: P. capensis, P. citricola VII, VIII, IX, X and XI, P. sp. botryosa-like 2, P. sp. meadii-like 1 and 2,
P. sp. tropicalis-like 2 and P. sp. multivesiculata-like 1 from Phytophthora major phylogenetic Clade 2;
P. castaneae and P. heveae from Clade 5; P. chlamydospora, P. gregata, P. sp. bitahaiensis-like and P. sp.
sylvatica-like 1, 2 and 3 from Clade 6; P. cinnamomi (Pc), P. parvispora, P. attenuata, P. sp. attenuata-like
1, 2 and 3 and P. ×heterohybrida from Clade 7; P. drechsleri, P. pseudocryptogea, P. ramorum (Pr) and P. sp.
kelmania from Clade 8, P. macrochlamydospora, P. sp. ×insolita-like, P. sp. ×kunnunara-like, P. sp.
×virginiana-like s.l. and three new taxa, P. sp. quininea-like, P. sp. ×Grenada 3-like and P. sp. ×Peru
4-like, from Clade 9; and P. sp. gallica-like 1 and 2 from Clade 10. The A1 and A2 mating types of
both Pc and Pr co-occurred. The A2 mating type of Pc was associated with severe dieback of montane
forests in northern Vietnam. Most other Phytophthora species, including Pr, were not associated with
obvious disease symptoms. It is concluded that (1) Vietnam is within the center of origin of most
Phytophthora taxa found including Pc and Pr, and (2) Phytophthora clades 2, 5, 6, 7, 8, 9, and 10 are
native to Indochina.info:eu-repo/semantics/publishedVersio
tackling malaria
Malaria is an infectious disease that affects over 216 million people worldwide, killing over 445,000 patients annually. Due to the constant emergence of parasitic resistance to the current antimalarial drugs, the discovery of new drug candidates is a major global health priority. Aiming to make the drug discovery processes faster and less expensive, we developed binary and continuous Quantitative Structure-Activity Relationships (QSAR) models implementing deep learning for predicting antiplasmodial activity and cytotoxicity of untested compounds. Then, we applied the best models for a virtual screening of a large database of chemical compounds. The top computational predictions were evaluated experimentally against asexual blood stages of both sensitive and multi-drug-resistant Plasmodium falciparum strains. Among them, two compounds, LabMol-149 and LabMol-152, showed potent antiplasmodial activity at low nanomolar concentrations (EC50 <500 nM) and low cytotoxicity in mammalian cells. Therefore, the computational approach employing deep learning developed here allowed us to discover two new families of potential next generation antimalarial agents, which are in compliance with the guidelines and criteria for antimalarial target candidates.publishersversionpublishe
Saúde mental e estratégias de coping em trabalhadores aeroportuários / Mental health and coping strategies in airport workers
O objetivo deste estudo foi identificar sinais e sintomas de transtornos psiquiátricos, e estratégias de coping utilizadas por trabalhadores aeroportuários. Participaram do estudo 203 trabalhadores aeroportuários. Utilizaram-se os seguintes instrumentos: questionário sociodemográfico, Questionário de Morbidade Psiquiátrica do Adulto e Escala de Modos de Enfrentamento de Problemas. De acordo com o Questionário de Morbidade Psiquiátrica do Adulto, 47 sujeitos (23,2%) apresentaram critério positivo sugestivo de sinais e sintomas de distúrbios psiquiátricos. Já segundo a Escala de Modos de Enfrentamento de Problemas, houve predomínio de estratégias “focadas no problema” e uma “busca de suporte social”, além do predomínio de estratégias “focadas na emoção”, em associação positiva com o enfrentamento focado na religiosidade e no pensamento fantasioso (p<0,0001), e maior suspeita de doença mental (p<0,000). Sugerem-se avaliação e acompanhamento psicológico dos trabalhadores, com intervenções de medida preventiva em saúde mental e ocupacional.
Caracteristicas demográficas e epidemiológicas de doadores aptos e inaptos clinicamente em um banco de sangue regional de Santa Cruz do Sul-RS
Analisar o perfil de doadores (aptos clínicos) e não doadores (inaptos clínicos), com relação às características demográficas e socioeconômicas, o tipo de doação predominante, bem como os principais motivos para a inaptidão clínica. O estudo, de caráter transversal, contou com 2.876 sujeitos, de ambos os sexos. De acordo com os resultados, observa-se que os homens apresentam porcentagem bastante superior (65,0%) em relação às mulheres (35,0%), quanto à aptidão clínica para a doação; já, as mulheres, apresentam maior porcentagem de inaptidão clínica (53,8%). De maneira geral, o perfil dos sujeitos, tanto aptos, quanto inaptos clinicamente, demonstra que, quanto às características demográficas e sócio-econômicas, a faixa etária predominante é de 18 a 29 anos, com ensino médio completo, solteiros e de etnia branca, sendo a maior parte semi-qualificado profissionalmente; quanto ao tipo de doação, há um destaque para a voluntária e, quanto ao motivo de inaptidão clínica, observam-se diferenças entre os sexos, onde os homens apresentam maior porcentagem de hematócrito elevado e hipertensão arterial e as mulheres, hematócrito baixo, gripe e hipotensão. Assim, pode-se concluir que a determinação do perfil do doador é importante para formular estratégias especificas para a captação de doadores de sangue
Nothophytophthora gen. nov., a new sister genus of Phytophthora from natural and semi-natural ecosystem
During various surveys of Phytophthora diversity in Europe, Chile and Vietnam slow growing oomycete
isolates were obtained from rhizosphere soil samples and small streams in natural and planted forest stands.
Phylogenetic analyses of sequences from the nuclear ITS, LSU, β-tubulin and HSP90 loci and the mitochondrial
cox1 and NADH1 genes revealed they belong to six new species of a new genus, officially described here as
Nothophytophthora gen. nov., which clustered as sister group to Phytophthora. Nothophytophthora species share
numerous morphological characters with Phytophthora: persistent (all Nothophytophthora spp.) and caducous
(N. caduca, N. chlamydospora, N. valdiviana, N. vietnamensis) sporangia with variable shapes, internal differentiation
of zoospores and internal, nested and extended (N. caduca, N. chlamydospora) and external (all Nothophytophthora
spp.) sporangial proliferation; smooth-walled oogonia with amphigynous (N. amphigynosa) and paragynous
(N. amphigynosa, N. intricata, N. vietnamensis) attachment of the antheridia; chlamydospores (N. chlamydospora)
and hyphal swellings. Main differing features of the new genus are the presence of a conspicuous, opaque plug
inside the sporangiophore close to the base of most mature sporangia in all known Nothophytophthora species and
intraspecific co-occurrence of caducity and non-papillate sporangia with internal nested and extended proliferation
in several Nothophytophthora species. Comparisons of morphological structures of both genera allow hypotheses
about the morphology and ecology of their common ancestor which are discussed. Production of caducous sporangia
by N. caduca, N. chlamydospora and N. valdiviana from Valdivian rainforests and N. vietnamensis from a
mountain forest in Vietnam suggests a partially aerial lifestyle as adaptation to these humid habitats. Presence of
tree dieback in all forests from which Nothophytophthora spp. were recovered and partial sporangial caducity of
several Nothophytophthora species indicate a pathogenic rather than a saprophytic lifestyle. Isolation tests from
symptomatic plant tissues in these forests and pathogenicity tests are urgently required to clarify the lifestyle of the
six Nothophytophthora species.info:eu-repo/semantics/publishedVersio
Unravelling hybridization in Phytophthora using phylogenomics and genome size estimation
The genus Phytophthora comprises many economically and ecologically important plant pathogens. Hybrid species have previously been identified in at least six of the 12 phylogenetic clades. These hybrids can potentially infect a wider host range and display enhanced vigour compared to their progenitors. Phytophthora hybrids therefore pose a serious threat to agriculture as well as to natural ecosystems. Early and correct identification of hybrids is therefore essential for adequate plant protection but this is hampered by the limitations of morphological and traditional molecular methods. Identification of hybrids is also important in evolutionary studies as the positioning of hybrids in a phylogenetic tree can lead to suboptimal topologies. To improve the identification of hybrids we have combined genotyping-by-sequencing (GBS) and genome size estimation on a genus-wide collection of 614 Phytophthora isolates. Analyses based on locus- and allele counts and especially on the combination of species-specific loci and genome size estimations allowed us to confirm and characterize 27 previously described hybrid species and discover 16 new hybrid species. Our method was also valuable for species identification at an unprecedented resolution and further allowed correct naming of misidentified isolates. We used both a concatenation- and a coalescent-based phylogenomic method to construct a reliable phylogeny using the GBS data of 140 non-hybrid Phytophthora isolates. Hybrid species were subsequently connected to their progenitors in this phylogenetic tree. In this study we demonstrate the application of two validated techniques (GBS and flow cytometry) for relatively low cost but high resolution identification of hybrids and their phylogenetic relations.info:eu-repo/semantics/publishedVersio
Whole-genome sequencing of 1,171 elderly admixed individuals from Brazil
As whole-genome sequencing (WGS) becomes the gold standard tool for studying population genomics and medical applications, data on diverse non-European and admixed individuals are still scarce. Here, we present a high-coverage WGS dataset of 1,171 highly admixed elderly Brazilians from a census-based cohort, providing over 76 million variants, of which ~2 million are absent from large public databases. WGS enables identification of ~2,000 previously undescribed mobile element insertions without previous description, nearly 5 Mb of genomic segments absent from the human genome reference, and over 140 alleles from HLA genes absent from public resources. We reclassify and curate pathogenicity assertions for nearly four hundred variants in genes associated with dominantly-inherited Mendelian disorders and calculate the incidence for selected recessive disorders, demonstrating the clinical usefulness of the present study. Finally, we observe that whole-genome and HLA imputation could be significantly improved compared to available datasets since rare variation represents the largest proportion of input from WGS. These results demonstrate that even smaller sample sizes of underrepresented populations bring relevant data for genomic studies, especially when exploring analyses allowed only by WGS
A comprehensive assessment of the transcriptome of cork oak (Quercus suber) through EST sequencing
Background: Cork oak (Quercus suber) is one of the rare trees with the ability to produce cork, a material widely used to make wine bottle stoppers, flooring and insulation materials, among many other uses. The molecular mechanisms of cork formation are still poorly understood, in great part due to the difficulty in studying a species with a long life-cycle and for which there is scarce molecular/genomic information. Cork oak forests are of great ecological importance and represent a major economic and social resource in Southern Europe and Northern Africa. However, global warming is threatening the cork oak forests by imposing thermal, hydric and many types of novel biotic stresses. Despite the economic and social value of the Q. suber species, few genomic resources have been developed, useful for biotechnological applications and improved forest management.
Results: We generated in excess of 7 million sequence reads, by pyrosequencing 21 normalized cDNA libraries derived from multiple Q. suber tissues and organs, developmental stages and physiological conditions. We deployed a stringent sequence processing and assembly pipeline that resulted in the identification of ~159,000 unigenes. These were annotated according to their similarity to known plant genes, to known Interpro domains, GO classes and E.C. numbers. The phylogenetic extent of this ESTs set was investigated, and we found that cork oak revealed a significant new gene space that is not covered by other model species or EST sequencing projects. The raw data, as well as the full annotated assembly, are now available to the community in a dedicated web portal at http://www.corkoakdb.org.
Conclusions: This genomic resource represents the first trancriptome study in a cork producing species. It can be explored to develop new tools and approaches to understand stress responses and developmental processes in forest trees, as well as the molecular cascades underlying cork differentiation and disease response.Peer Reviewe