Text mining analysis to understand the impact of online news on public health response: case of syphilis epidemic in Brazil.

Background: To effectively combat the rising incidence of syphilis, the Brazilian Ministry of Health (MoH) created a National Rapid Response to Syphilis with actions aimed at bolstering epidemiological surveillance of acquired, congenital syphilis, and syphilis during pregnancy complemented with communication activities to raise population awareness and to increase uptake of testing that targeted mass media outlets from November 2018 to March 2019 throughout Brazil, and mainly areas with high rates of syphilis. This study analyzes the volume and quality of online news content on syphilis in Brazil between 2015 and 2019 and examines its effect on testing. Methods: The collection and processing of online news were automated by means of a proprietary digital health ecosystem established for the study. We applied text data mining techniques to online news to extract patterns from categories of text. The presence and combination of such categories in collected texts determined the quality of news that were analyzed to classify them as high-, medium-and low-quality news. We examined the correlation between the quality of news and the volume of syphilis testing using Spearman's Rank Correlation Coefficient. Results: 1,049 web pages were collected using a Google Search API, of which 630 were categorized as earned media. We observed a steady increase in the number of news on syphilis in 2015 (n = 18), 2016 (n = 26), and 2017 (n = 42), with a substantial rise in the number of news in 2018 (n = 107) and 2019 (n = 437), although the relative proportion of high-quality news remained consistently high (77.6 and 70.5% respectively) and in line with similar years. We found a correlation between news quality and syphilis testing performed in primary health care with an increase of 82.32, 78.13, and 73.20%, respectively, in the three types of treponemal tests used to confirm an infection. Conclusion: Effective communication strategies that lead to dissemination of high quality of information are important to increase uptake of public health policy actions.

Extraction of collagenolytic proteases from Aspergillus heteromorphus URM 0269 in an aqueous two-phase system for application in collagen hydrolysis.

Collagenolytic proteases produced by Aspergillus heteromorphus URM0269 were extracted using a PEG/sulfate aqueous two-phase system (ATPS). A 23 factorial design was performed to analyze the independent variables: PEG molar mass (MPEG), PEG concentration (CPEG), and sulfate concentration (Csulf). The extracted proteases were also evaluated for their optimum pH and stability at different pH levels (4.0 - 11.0) after 20 h of incubation. Collagen was extracted from mutton snapper (Lutjanus analis) skin using acetic acid (0.5 mol L-1). The enzyme was preferentially partitioned to the PEG-rich phase (K > 1), whose highest purification factor and recovery (PF = 6.256 and Y = 404.432%) were obtained under specific conditions: MPEG 8000 g.mol-1, CPEG 30%, Csulf 10%. The ATPS extraction provided an enzymatic activity range of pH 7.0 - 11.0, exhibiting greater stability compared to the crude extract. Approximately 80% of protease activity was maintained after 20 hours of incubation at all analyzed pH levels, except pH 11.0. Collagen extraction from L. analis skin yielded 8.056%, and both crude extract samples and ATPS-derived samples successfully hydrolyzed the extracted collagen, reaching peak hydrolysis after 36 hours of treatment. These findings demonstrate the feasibility of extracting highly purified and active proteases capable of hydrolyzing L. analis collagen.

Effects of lingual frenotomy on breastfeeding and electrical activity of the masseter and suprahyoid muscles.

PURPOSE: To analyze the effects of lingual frenotomy on the breastfeeding of infants, based on the electrical activity of the masseter and suprahyoid muscles and assessment of the breastfeeding. METHODS: Observational study developed between October 2017 and June 2018 with a sample of 20 newborns and infants who attended a dental clinic and were diagnosed with ankyloglossia. Another 20 were excluded for meeting some of the following exclusion criteria: babies more than 6 months old, who were not on exclusive or mixed breastfeeding, who had other clinical impairments that interfered with breastfeeding, who had other foods introduced into their diet, who had neurological changes and/or craniofacial deformities, and/or who did not finish all the stages of the study. Breastfeeding was assessed with the UNICEF Breastfeeding Assessment and Observation Protocol, while the muscle electrical activity was assessed with the Electrical Activity Assessment Protocol for the Masseter and Suprahyoid Muscles in Newborns During Breastfeeding. The same speech-language-hearing therapist conducted the two assessments both before the conventional frenotomy and 7 days after it. RESULTS: The signs suggestive of breastfeeding difficulties changed 7 days after the surgery, with a p-value ≤ 0.002 for general observation of the mother, position of the infant, latch, and sucking. The maximum voluntary contraction of the masseter was the only integral parameter with a difference, as the electrical activity had decreased. CONCLUSION: Behaviors favorable to breastfeeding increased 7 days after the frenotomy in all the breastfeeding assessment categories, whereas the electrical activity of the masseter decreased.

Effects of lingual frenotomy on breastfeeding and electrical activity of the masseter and suprahyoid muscles / Efeito da frenotomia lingual na amamentação e na atividade elétrica dos músculos masseter e supra-hióideos

ABSTRACT Purpose To analyze the effects of lingual frenotomy on the breastfeeding of infants, based on the electrical activity of the masseter and suprahyoid muscles and assessment of the breastfeeding. Methods Observational study developed between October 2017 and June 2018 with a sample of 20 newborns and infants who attended a dental clinic and were diagnosed with ankyloglossia. Another 20 were excluded for meeting some of the following exclusion criteria: babies more than 6 months old, who were not on exclusive or mixed breastfeeding, who had other clinical impairments that interfered with breastfeeding, who had other foods introduced into their diet, who had neurological changes and/or craniofacial deformities, and/or who did not finish all the stages of the study. Breastfeeding was assessed with the UNICEF Breastfeeding Assessment and Observation Protocol, while the muscle electrical activity was assessed with the Electrical Activity Assessment Protocol for the Masseter and Suprahyoid Muscles in Newborns During Breastfeeding. The same speech-language-hearing therapist conducted the two assessments both before the conventional frenotomy and 7 days after it. Results The signs suggestive of breastfeeding difficulties changed 7 days after the surgery, with a p-value ≤ 0.002 for general observation of the mother, position of the infant, latch, and sucking. The maximum voluntary contraction of the masseter was the only integral parameter with a difference, as the electrical activity had decreased. Conclusion Behaviors favorable to breastfeeding increased 7 days after the frenotomy in all the breastfeeding assessment categories, whereas the electrical activity of the masseter decreased.

RESUMO Objetivo Analisar os efeitos da frenotomia lingual na amamentação de recém-nascidos, com base na atividade elétrica dos músculos masseter e supra-hióideos e avaliação da mamada. Método Estudo observacional, desenvolvido entre outubro de 2017 e junho de 2018. Amostra de 20 recém-nascidos e lactentes de uma clínica odontológica, diagnosticados com anquiloglossia; 20 foram excluídos por se encaixarem em algum dos critérios de exclusão: ter mais de seis meses de vida, não fazer aleitamento materno exclusivo ou misto, apresentar outro comprometimento clínico que interfira na amamentação, ter iniciado a ingestão de outros alimentos, alterações neurológicas e/ou deformidades craniofaciais e não ter finalizado todas as etapas do estudo. A avaliação da amamentação seguiu o Protocolo de Observação e Avaliação da Mamada da UNICEF, e a avaliação da atividade elétrica muscular o Protocolo de Avaliação da Atividade Elétrica dos Músculos Masseter e Supra-hióideos em Recém-Nascidos Durante a Alimentação, ambas realizadas pela mesma fonoaudióloga antes da frenotomia convencional e sete dias após. Resultados Os sinais sugestivos de dificuldade na amamentação mudaram sete dias após a cirurgia, com valor de p≤0,002 para a observação geral da mãe, posição do bebê, pega e sucção. Houve diferença apenas no parâmetro integral da Contração Voluntária Máxima do masseter, com diminuição da atividade elétrica. Conclusão Sete dias após a frenotomia observou-se aumento de comportamentos favoráveis ​​à amamentação em todas as categorias de avaliação da mamada e diminuição da atividade elétrica do masseter.

Engineering Resistance against Sclerotinia sclerotiorum Using a Truncated NLR (TNx) and a Defense-Priming Gene.

The association of both cell-surface PRRs (Pattern Recognition Receptors) and intracellular receptor NLRs (Nucleotide-Binding Leucine-Rich Repeat) in engineered plants have the potential to activate strong defenses against a broad range of pathogens. Here, we describe the identification, characterization, and in planta functional analysis of a novel truncated NLR (TNx) gene from the wild species Arachis stenosperma (AsTIR19), with a protein structure lacking the C-terminal LRR (Leucine Rich Repeat) domain involved in pathogen perception. Overexpression of AsTIR19 in tobacco plants led to a significant reduction in infection caused by Sclerotinia sclerotiorum, with a further reduction in pyramid lines containing an expansin-like B gene (AdEXLB8) potentially involved in defense priming. Transcription analysis of tobacco transgenic lines revealed induction of hormone defense pathways (SA; JA-ET) and PRs (Pathogenesis-Related proteins) production. The strong upregulation of the respiratory burst oxidase homolog D (RbohD) gene in the pyramid lines suggests its central role in mediating immune responses in plants co-expressing the two transgenes, with reactive oxygen species (ROS) production enhanced by AdEXLB8 cues leading to stronger defense response. Here, we demonstrate that the association of potential priming elicitors and truncated NLRs can produce a synergistic effect on fungal resistance, constituting a promising strategy for improved, non-specific resistance to plant pathogens.

Similarity Analysis in Understanding Online News in Response to Public Health Crisis.

BACKGROUND: The "Syphilis No!" campaign the Brazilian Ministry of Health (MoH) launched between November 2018 and March 2019, brought forward the concept "Test, Treat and Cure" to remind the population of the importance of syphilis prevention. In this context, this study aims to analyze the similarity of syphilis online news to comprehend how public health communication interventions influence media coverage of the syphilis issue. METHODS: This paper presented a computational approach to assess the effectiveness of communication actions on a public health problem. Data were collected between January 2015 and December 2019 and processed using the Hermes ecosystem, which utilizes text mining and machine learning algorithms to cluster similar content. RESULTS: Hermes identified 1049 google-indexed web pages containing the term 'syphilis' in Brazil. Of these, 619 were categorized as news stories. In total, 157 were grouped into clusters of at least two similar news items and a single cluster with 462 news classified as "single" for not featuring similar news items. From these, 19 clusters were identified in the pre-campaign period, 23 during the campaign, and 115 in the post-campaign. CONCLUSIONS: The findings presented in this study show that the volume of syphilis-related news reports has increased in recent years and gained popularity after the SNP started, having been boosted during the campaign and escalating even after its completion.

Religious/spiritual coping, symptoms of depression, stress, and anxiety in caregivers of children and adolescents with type 1 diabetes.

BACKGROUND: It was verified the level of religiosity and spirituality, and symptoms of depression, stress, and anxiety of caregivers of children and adolescents with type 1 diabetes, and its interference in glycaemic control. METHODS: Socio-economic and demographic data were collected from caregivers of 59 children and adolescents with type 1 diabetes and obtained dosages of fasting glucose (FG); postprandial glycaemia (PPG); fructosamine (FRUTO); and HbA1c, as well as the glycaemic variability-∆HbA1c. Levels of religiosity were obtained by the DUREL scale; the use of religious/spiritual coping was verified by the SRCOPE-Brief scale. Symptoms of depression, anxiety, and stress were analysed by the DASS-21 scale. The correlations between the variables were analysed by the Pearson coefficient, with significance at 5% level. RESULTS: Inverse correlations were observed between caregivers' schooling with PPG (r = -0.30; P = 0.002) and FRUTO (r = -0.34; P = 0.008) and between family income and FRUTO (r = -0.37; P = 0.004). Direct, moderate correlations were observed between negative religious/spiritual coping (NSRCOPE) with symptoms of depression (r = 0.588; P < 0.0001), stress (r = 0.500; P < 0.0001), and anxiety (r = 0.551; P < 0.0001). CONCLUSION: The direct association between NSRCOPE with symptoms of depression, stress, and anxiety was the highlighted item in the present study emphasizing the need for greater attention to the emotional health of informal caregivers of children and adolescents with DM1. It is necessary to reflect on the religious/spiritual support especially for the main caregiver of children and adolescents with DM1.

Coronavirus disease-related in-hospital mortality: a cohort study in a private healthcare network in Brazil.

COVID-19-related in-hospital mortality has been reported at 30.7-47.3% in Brazil, however studies assessing exclusively private hospitals are lacking. This is important because of significant differences existing between the Brazilian private and public healthcare systems. We aimed to determine the COVID-19-related in-hospital mortality and associated risk factors in a Brazilian private network from March/2020 to March/2021. Data were extracted from institutional database and analyzed using Cox regression model. Length of hospitalization and death-related factors were modeled based on available independent variables. In total, 38,937 COVID-19 patients were hospitalized of whom 3058 (7.8%) died. Admission to the intensive care unit occurred in 62.5% of cases, and 11.5% and 3.8% required mechanical ventilation (MV) and renal replacement therapy (RRT), respectively. In the adjusted model, age ≥ 61 years-old, comorbidities, and the need for MV and/or RRT were significantly associated with increased mortality (p < 0.05). Obesity and hypertension were associated with the need for MV and RRT (p < 0.05).

Spontaneous generation of diversity in Arachis neopolyploids (Arachis ipaënsis × Arachis duranensis)4x replays the early stages of peanut evolution.

Polyploidy is considered a driving force in plant evolution and domestication. Although in the genus Arachis, several diploid species were traditionally cultivated for their seeds, only the allotetraploid peanut Arachis hypogaea became the successful, widely spread legume crop. This suggests that polyploidy has given selective advantage for domestication of peanut. Here, we study induced allotetraploid (neopolyploid) lineages obtained from crosses between the peanut's progenitor species, Arachis ipaënsis and Arachis duranensis, at earlier and later generations. We observed plant morphology, seed dimensions, and genome structure using cytogenetics (FISH and GISH) and SNP genotyping. The neopolyploid lineages show more variable fertility and seed morphology than their progenitors and cultivated peanut. They also showed sexual and somatic genome instability, evidenced by changes of number of detectable 45S rDNA sites, and extensive homoeologous recombination indicated by mosaic patterns of chromosomes and changes in dosage of SNP alleles derived from the diploid species. Genome instability was not randomly distributed across the genome: the more syntenic chromosomes, the higher homoeologous recombination. Instability levels are higher than observed on peanut lines, therefore it is likely that more unstable lines tend to perish. We conclude that early stages of the origin and domestication of the allotetraploid peanut involved two genetic bottlenecks: the first, common to most allotetraploids, is composed of the rare hybridization and polyploidization events, followed by sexual reproductive isolation from its wild diploid relatives. Here, we suggest a second bottleneck: the survival of the only very few lineages that had stronger mechanisms for limiting genomic instability.

Defining the combined stress response in wild Arachis.

Nematodes and drought are major constraints in tropical agriculture and often occur simultaneously. Plant responses to these stresses are complex and require crosstalk between biotic and abiotic signaling pathways. In this study, we explored the transcriptome data of wild Arachis species subjected to drought (A-metaDEG) and the root-knot nematode Meloidogyne arenaria (B-metaDEG) via meta-analysis, to identify core-stress responsive genes to each individual and concurrent stresses in these species. Transcriptome analysis of a nematode/drought bioassay (cross-stress) showed that the set of stress responsive DEGs to concurrent stress is distinct from those resulting from overlapping A- and B-metaDEGs, indicating a specialized and unique response to combined stresses in wild Arachis. Whilst individual biotic and abiotic stresses elicit hormone-responsive genes, most notably in the jasmonic and abscisic acid pathways, combined stresses seem to trigger mainly the ethylene hormone pathway. The overexpression of a cross-stress tolerance candidate gene identified here, an endochitinase-encoding gene (AsECHI) from Arachis stenosperma, reduced up to 30% of M. incognita infection and increased post-drought recovery in Arabidopsis plants submitted to both stresses. The elucidation of the network of cross-stress responsive genes in Arachis contributes to better understanding the complex regulation of biotic and abiotic responses in plants facilitating more adequate crop breeding for combined stress tolerance.

Brazilian Kayabi Indian accessions of peanut, Arachis hypogaea (Fabales, Fabaceae): origin, diversity and evolution.

Peanut is a crop of the Kayabi tribe, inhabiting the Xingu Indigenous Park, Brazil. Morphological analysis of Xingu accessions showed variation exceeding that described for cultivated peanuts. This raised questions as to the origin of the Xingu accessions: are they derived from different species, or is their diversity a result of different evolutionary and selection processes? To answer these questions, cytogenetic and genotyping analyses were conducted. The karyotypes of Xingu accessions analyzed are very similar to each other, to an A. hypogaea subsp. fastigiata accession and to the wild allotetraploid A. monticola. The accessions share the number and general morphology of the chromosomes; DAPI+ bands; 5S and 45S rDNA loci distribution and a high genomic affinity with A. duranensis and A. ipaënsis genomic probes. However, the number of CMA3+ bands differs from those determined for A. hypogaea and A. monticola, which are also different from each other. SNP genotyping grouped all Arachis allotetraploids into four taxonomic groups: Xingu accessions were closer to A. monticola and A. hypogaea subsp. hypogaea. Our data suggests that the morphological diversity within these accessions is not associated with a different origin and can be attributed to morphological plasticity and different selection by the Indian tribes.

Suicidal thinking, depression, and religiosity in a freedom-deprived population.

OBJECTIVE: to analyze the influence of sociodemographic variables, prison context, religiosity, and symptoms of depression on the presence of suicidal thinking in a population deprived of liberty. METHOD: a cross-sectional study with a quantitative approach, conducted with 228 participants, based on a sociodemographic questionnaire, on the prison context, and on the presence of suicidal thinking, from the Duke Religiosity Scale and the Depression, Anxiety and Stress Scale (DASS-21). RESULTS: the variables that showed a statistically significant correlation were the following: female gender, not having a partner, working inside the penitentiary, being a primary defendant and using controlled medication, and females are 7.2 times more likely to present suicidal thinking, for each point more in the depression score, increases by 21% in the chances and not having a partner increases the chances of thinking about suicide by three times. Although the scores of religiosity were high, they did not present a statistically significant correlation with the presence of suicidal thinking. CONCLUSION: the prison context is complex and contains peculiarities that cause the involvement of mental health problems, as well as self-harming thoughts. Considering the relevance of the subject at issue, this work stands out in view of the scarce scientific production on the subject.

Fructo-oligosaccharides production by an Aspergillus aculeatus commercial enzyme preparation with fructosyltransferase activity covalently immobilized on Fe3O4-chitosan-magnetic nanoparticles.

Pectinex Ultra SP-L, a commercial enzyme preparation with fructosyltransferase activity, was successfully immobilized by covalent binding to Fe3O4-chitosan- magnetic nanoparticles. Immobilization carried out according to a 23-full factorial design where glutaraldehyde concentration, activation time and time of contact between enzyme and support were selected as the independent variables and immobilization yield as the response. The highest immobilization yield (94.84%) was obtained using 3.0% (v/v) glutaraldehyde and activation and contact times of 180 and 30 min, respectively. The immobilized biocatalyst, which showed for both hydrolytic and transfructosylating activities optimum pH and temperature of 7.0 and 60 °C, respectively, retained 70 and 86% of them after 6 cycles of reuse. A kinetic/thermodynamic study focused on thermal inactivation of the immobilized construct indicated high thermostability at temperatures commonly used for fructo-oligosaccharides (FOS) production. Maximum FOS concentration obtained in lab-scale experiments was 101.56 g L-1, with predominant presence of 1-kestose in the reaction mixture. The results obtained in this study suggest that the immobilized-enzyme preparation may be effectively exploited for FOS production and easily recovered from the reaction mixture by action of a magnetic field.

Suicidal thinking, depression, and religiosity in a freedom-deprived population / Pensamento suicida, depressão e religiosidade em uma população privada de liberdade / Pensamiento suicida, depresión y religiosidad en una población privada de libertad

Objective: to analyze the influence of sociodemographic variables, prison context, religiosity, and symptoms of depression on the presence of suicidal thinking in a population deprived of liberty. Method: a cross-sectional study with a quantitative approach, conducted with 228 participants, based on a sociodemographic questionnaire, on the prison context, and on the presence of suicidal thinking, from the Duke Religiosity Scale and the Depression, Anxiety and Stress Scale (DASS-21). Results: the variables that showed a statistically significant correlation were the following: female gender, not having a partner, working inside the penitentiary, being a primary defendant and using controlled medication, and females are 7.2 times more likely to present suicidal thinking, for each point more in the depression score, increases by 21% in the chances and not having a partner increases the chances of thinking about suicide by three times. Although the scores of religiosity were high, they did not present a statistically significant correlation with the presence of suicidal thinking. Conclusion: the prison context is complex and contains peculiarities that cause the involvement of mental health problems, as well as self-harming thoughts. Considering the relevance of the subject at issue, this work stands out in view of the scarce scientific production on the subject.

Objetivo: analisar a influência das variáveis sociodemográficas, de contexto prisional, religiosidade e sintomas de depressão sobre a presença do pensamento suicida em uma população privada de liberdade. Método: estudo transversal, com abordagem quantitativa, realizado com 228 participantes, a partir de um questionário sociodemográfico, de contexto prisional e presença do pensamento suicida, da escala de Religiosidade de Duke e da Escala de Depressão, Ansiedade e Estresse (DASS-21). Resultados: as variáveis que apresentaram correlação estatisticamente significativa foram: sexo feminino, não possuir companheiro(a), trabalhar dentro da penitenciária, ser réu primário e fazer uso de medicamento controlado, sendo que o sexo feminino possui 7,2 vezes mais chances de apresentar pensamento suicida, para cada ponto a mais no escore de depressão, aumenta em 21% nas chances e não possuir companheiro(a) aumenta em três vezes as chances de pensar em suicídio. Ainda que os escores de religiosidade tenham sido elevados, não apresentaram correlação estatisticamente significativa com a presença do pensamento suicida. Conclusão: o contexto prisional é complexo e contém peculiaridades que ensejam o acometimento dos agravos à saúde mental, bem como dos pensamentos autolesivos. Considerando a relevância do assunto em questão, esse trabalho se destaca diante da escassa produção científica acerca do tema.

Objetivo: analizar la influencia de variables sociodemográficas de contexto carcelario, religiosidad y síntomas de depresión en la presencia de pensamientos suicidas en una población privada de libertad. Método: estudio transversal, con enfoque cuantitativo, realizado con 228 participantes, basado en un cuestionario sociodemográfico, de contexto carcelario y la presencia de pensamientos suicidas, la Escala de Religiosidad de Duke y la Escala de Depresión, Ansiedad y Estrés (DASS-21). Resultados: las variables que mostraron una correlación estadísticamente significativa fueron: género femenino, no tener pareja, trabajar en la prisión, ser reo primario y usar medicamentos controlados, advirtiéndose que el sexo femenino presenta 7,2 veces más posibilidades de tener pensamiento suicida, por cada punto adicional en el puntaje de depresión, aumenta las posibilidades en un 21% y no tener una pareja aumenta tres veces las posibilidades de pensar en el suicidio tres Aunque los puntajes de religiosidad fueron altos, no mostraron una correlación estadísticamente significativa con la presencia de pensamientos suicidas. Conclusión: el contexto de la prisión es complejo y conlleva peculiaridades que causan el deterioro de los problemas de salud mental, así como los pensamientos autolesivos. Teniendo en cuenta la relevancia del tema en cuestión, este trabajo se destaca en vista de la escasa producción científica sobre el tema.

Contrasting Effects of Wild Arachis Dehydrin Under Abiotic and Biotic Stresses.

Plant dehydrins (DNHs) belong to the LEA (Late Embryogenesis Abundant) protein family and are involved in responses to multiple abiotic stresses. DHNs are classified into five subclasses according to the organization of three conserved motifs (K-; Y-; and S-segments). In the present study, the DHN protein family was characterized by molecular phylogeny, exon/intron organization, protein structure, and tissue-specificity expression in eight Fabaceae species. We identified 20 DHN genes, encompassing three (YnSKn, SKn, and Kn) subclasses sharing similar gene organization and protein structure. Two additional low conserved DHN Φ-segments specific to the legume SKn-type of proteins were also found. The in silico expression patterns of DHN genes in four legume species (Arachis duranensis, A. ipaënsis, Glycine max, and Medicago truncatula) revealed that their tissue-specific regulation is associated with the presence or absence of the Y-segment. Indeed, DHN genes containing a Y-segment are mainly expressed in seeds, whereas those without the Y-segment are ubiquitously expressed. Further qRT-PCR analysis revealed that, amongst stress responsive dehydrins, a SKn-type DHN gene from A. duranensis (AdDHN1) showed opposite response to biotic and abiotic stress with a positive regulation under water deficit and negative regulation upon nematode infection. Furthermore, transgenic Arabidopsis lines overexpressing (OE) AdDHN1 displayed improved tolerance to multiple abiotic stresses (freezing and drought) but increased susceptibility to the biotrophic root-knot nematode (RKN) Meloidogyne incognita. This contradictory role of AdDHN1 in responses to abiotic and biotic stresses was further investigated by qRT-PCR analysis of transgenic plants using a set of stress-responsive genes involved in the abscisic acid (ABA) and jasmonic acid (JA) signaling pathways and suggested an involvement of DHN overexpression in these stress-signaling pathways.

Comparative root transcriptome of wild Arachis reveals NBS-LRR genes related to nematode resistance.

BACKGROUND: The Root-Knot Nematode (RKN), Meloidogyne arenaria, significantly reduces peanut grain quality and yield worldwide. Whilst the cultivated species has low levels of resistance to RKN and other pests and diseases, peanut wild relatives (Arachis spp.) show rich genetic diversity and harbor high levels of resistance to many pathogens and environmental constraints. Comparative transcriptome analysis can be applied to identify candidate resistance genes. RESULTS: Transcriptome analysis during the early stages of RKN infection of two peanut wild relatives, the highly RKN resistant Arachis stenosperma and the moderately susceptible A. duranensis, revealed genes related to plant immunity with contrasting expression profiles. These included genes involved in hormone signaling and secondary metabolites production and also members of the NBS-LRR class of plant disease resistance (R) genes. From 345 NBS-LRRs identified in A.duranensis reference genome, 52 were differentially expressed between inoculated and control samples, with the majority occurring in physical clusters unevenly distributed on eight chromosomes with preferential tandem duplication. The majority of these NBS-LRR genes showed contrasting expression behaviour between A. duranensis and A. stenosperma, particularly at 6 days after nematode inoculation, coinciding with the onset of the Hypersensitive Response in the resistant species. The physical clustering of some of these NBS-LRR genes correlated with their expression patterns in the contrasting genotypes. Four NBS-LRR genes exclusively expressed in A. stenosperma are located within clusters on chromosome Aradu. A09, which harbors a QTL for RKN resistance, suggesting a functional role for their physical arrangement and their potential involvement in this defense response. CONCLUSION: The identification of functional novel R genes in wild Arachis species responsible for triggering effective defense cascades can contribute to the crop genetic improvement and enhance peanut resilience to RKN.

Early responses to dehydration in contrasting wild Arachis species.

Wild peanut relatives (Arachis spp.) are genetically diverse and were selected throughout evolution to a range of environments constituting, therefore, an important source of allelic diversity for abiotic stress tolerance. In particular, A. duranensis and A. stenosperma, the parents of the reference Arachis A-genome genetic map, show contrasting transpiration behavior under limited water conditions. This study aimed to build a comprehensive gene expression profile of these two wild species under dehydration stress caused by the withdrawal of hydroponic nutrient solution. For this purpose, roots of both genotypes were collected at seven time-points during the early stages of dehydration and used to construct cDNA paired-end libraries. Physiological analyses indicated initial differences in gas exchange parameters between the drought-tolerant genotype of A. duranensis and the drought-sensitive genotype of A. stenosperma. High-quality Illumina reads were mapped against the A. duranensis reference genome and resulted in the identification of 1,235 and 799 Differentially Expressed Genes (DEGs) that responded to the stress treatment in roots of A. duranensis and A. stenosperma, respectively. Further analysis, including functional annotation and identification of biological pathways represented by these DEGs confirmed the distinct gene expression behavior of the two contrasting Arachis species genotypes under dehydration stress. Some species-exclusive and common DEGs were then selected for qRT-PCR analysis, which corroborated the in silico expression profiling. These included genes coding for regulators and effectors involved in drought tolerance responses, such as activation of osmosensing molecular cascades, control of hormone and osmolyte content, and protection of macromolecules. This dataset of transcripts induced during the dehydration process in two wild Arachis genotypes constitute new tools for the understanding of the distinct gene regulation processes in these closely related species but with contrasting drought responsiveness. In addition, our findings provide insights into the nature of drought tolerance in wild germoplasm, which might be explored as novel sources of diversity and useful wild alleles to develop climate-resilient crop varieties.

Comparative transcriptomic analysis indicates genes associated with local and systemic resistance to Colletotrichum graminicola in maize.

The hemibiotrophic fungus Colletotrichum graminicola may cause severe damage to maize, affecting normal development of the plant and decreasing grain yield. In this context, understanding plant defense pathways at the inoculation site and systemically in uninoculated tissues can help in the development of genetic engineering of resistance against this pathogen. Previous work has discussed the molecular basis of maize - C. graminicola interaction. However, many genes involved in defense have not yet been exploited for lack of annotation in public databases. Here, changes in global gene expression were studied in root, male and female inflorescences of maize under local and systemic fungal infection treatments, respectively. RNA-Seq with qPCR was used to indicate genes involved in plant defense. We found that systemic acquired resistance induction in female inflorescences mainly involves accumulation of salicylic acid (SA)-inducible defense genes (ZmNAC, ZmHSF, ZmWRKY, ZmbZIP and PR1) and potential genes involved in chromatin modification. Furthermore, transcripts involved in jasmonic acid (JA) and ethylene (ET) signaling pathways were also accumulated and may participate in plant immunity. Moreover, several genes were functionally re-annotated based on domain signature, indicating novel candidates to be tested in strategies involving gene knockout and overexpression in plants.

Ex vitro hairy root induction in detached peanut leaves for plant-nematode interaction studies.

BACKGROUND: Peanut (Arachis hypogaea) production is largely affected by a variety of abiotic and biotic stresses, including the root-knot nematode (RKN) Meloidogyne arenaria that causes yield losses worldwide. Transcriptome studies of wild Arachis species, which harbor resistance to a number of pests and diseases, disclosed several candidate genes for M. arenaria resistance. Peanut is recalcitrant to genetic transformation, so the use of Agrobacterium rhizogenes-derived hairy roots emerged as an alternative for in-root functional characterization of these candidate genes. RESULTS: The present report describes an ex vitro methodology for hairy root induction in detached leaves based on the well-known ability of peanut to produce roots spontaneously from its petiole, which can be maintained for extended periods under high-humidity conditions. Thirty days after infection with the A. rhizogenes 'K599' strain, 90% of the detached leaves developed transgenic hairy roots with 5 cm of length in average, which were then inoculated with M. arenaria. For improved results, plant transformation, and nematode inoculation parameters were adjusted, such as bacterial cell density and growth stage; moist chamber conditions and nematode inoculum concentration. Using this methodology, a candidate gene for nematode resistance, AdEXLB8, was successfully overexpressed in hairy roots of the nematode-susceptible peanut cultivar 'Runner', resulting in 98% reduction in the number of galls and egg masses compared to the control, 60 days after M. arenaria infection. CONCLUSIONS: This methodology proved to be more practical and cost-effective for functional validation of peanut candidate genes than in vitro and composite plant approaches, as it requires less space, reduces analysis costs and displays high transformation efficiency. The reduction in the number of RKN galls and egg masses in peanut hairy roots overexpressing AdEXLB8 corroborated the use of this strategy for functional characterization of root expressing candidate genes. This approach could be applicable not only for peanut-nematode interaction studies but also to other peanut root diseases, such as those caused by fungi and bacteria, being also potentially extended to other crop species displaying similar petiole-rooting competence.