Induction of somatic embryogenesis as an example of stress-related plant reactions

In this review, we address the role of stress as one of the principal causes for a cell or tissue to change its pre-existing somatic program, reprogramming itself to express the embryogenic pathway. The focus of this paper is the effect of different stress conditions on the induction phase of plant somatic embryogenesis, as well as the development of embryogenic competence as a result of the applied stresses. We also present a variety of data that link plant somatic embryogenesis, DNA methylation and oxidative stress response

Pathogenic fungi: an unacknowledged risk at coastal resorts? New insights on microbiological sand quality in Portugal

Whilst the potential impact on beach users from microorganisms in water has received considerable attention, there has been relatively little investigation into microbial contaminants in sand. Thirty three beaches across Portugal were analyzed during a five year period (2006–2010) to determine the presence of yeasts, pathogenic fungi, dermatophytes, total coliforms, Escherichia coli and intestinal enterococci in sand. Our results showed that 60.4% of the samples were positive for fungi and that 25.2% were positive for the bacterial parameters. The most frequent fungal species found were Candida sp. and Aspergillus sp., whereas intestinal enterococci were the most frequently isolated bacteria. Positive associations were detected among analyzed parameters and country-regions but none among those parameters and sampling period. Regarding threshold values, we propose 15 cfu/g for yeasts, 17 cfu/g for potential pathogenic fungi, 8 cfu/g for dermatophytes, 25 cfu/g for E. coli, and 10 cfu/g for intestinal enterococci

Estudos sobre a nutrição mineral do arroz: XI. Marcha de absorção de micronutrientes pela variedade IAC-47

Dry matter yield and uptake of B, Cu, Fe, Mn and Zn by the rice variety IAC-47 were studied under controlled conditions, namely, by growing plants in nutrient solution and by falcing samples for analyses in set physiological periods. It was observed that only the curves describing dry matter production and accumulation of B and Fe was verified.A produção de matéria seca e a absorção de micronutrientes (B, Cu, Fe, Mn e Zn) pelo arroz var. IAC-47 foram estudadas usando-se plantas cultivadas em solução nutritiva. Verificou-se que: enquanto as curvas que descrevem o crescimento e a acumulação de B e Fe mostram tendência sigmóide, as demais não o fazem, evidência de redistribuição foi observada somente nos casos do B (diminuição no conteúdo foliar) e no do Fe (diminuição no conteúdo da raiz)

Estudos sobre a nutrição mineral do arroz: VII. exigências nutricionais das variedades IAC-25 e IAC-47

Rice plants, varieties IAC 25 and IAC 47, were grown in nutrient solution till the end of the life cycle when they were analysed both for macro and micronutrients. Main conclusions were the following: IAC 47, higher yielding, showed larger requirements than IAC 25; for production (total) and export (grain), the demand for nutrients was the same in both varieties.As exigências nutricionais das variedades de arroz IAC 25 e IAC 47 foram determinadas analisando-se os diferentes órgãos de plantas cultivadas em solução nutritiva até o fim do ciclo. Verificou-se serem distintas as exigências, maior na IAC 47 (mais tardia) que deu também maior produção de grãos com casca

Studies on the mineral nutrition of the rice plant: IX. time course on the uptake of macronutrients by the variety IAC-47

Rice plants, variety IAC-47, were grown in the nº 2 nutrient solution of HOAGLAND & ARNON (1950) until the end of the life cycle. Plants were sampled at well defined physiological periods for analyses. It was verified that trends for levvelling off occurred in the case of accumulation of N, K and Ca. Translocation from leaves to grain was observed with respect to N, P and K. Maximum rates of uptake of all elements took place from 50 to 100 days after germination.Foram estudadas, em condições controladas, a acumulação de matéria seca e a de macronutrientes na variedade de arroz IAC-47. Ambos os processos em geral são descritos por sigmóides típicas; picos para os valores totais de produção de matéria seca e de acumulação de elementos entre: 100 e 140 dias depois da germinação

Estudos sobre a nutrição mineral do arroz: XIII. efeitos das deficiências de micronutrientes nas variedades IAC-25 e IAC-47

Rice plants were grown in nutrient solution lither in the presence or in the absence of B, Cu and Zn. The symptoms of deficiency were usually in agreement with those described in the literature. Growth of the variety IAC-47 (number of leaves, tillering and total dry matter) was relatively more affected; this variety, however did produce grains under the minus Cu treatment (one fourth of the yield observed in the "complete" treatment), which did not happen in the case of the other variety. At the beginning of the grain filling period the following leaf contents could be considered as indication of deficiency: B-13 to 25 ppm; Zn-20 ppm; no conclusion could be drawn with respect to Cu levels.Plantas de arroz, variedades IAC-25 e IAC-47 foram cultivadas em solução nutritiva e com deficiência de B, Cu e Zn. Foram obtidos sintomas de carência dos três micronutrientes. As deficiências induzidas provocaram diminuição na matéria seca total e no número de folhas das duas variedades. O mesmo ocorreu no numero de perfilhos da var. IAC-47. Foi feita a determinação dos teores dos micronutrientes nas plantas submetidas aos diferentes tratamentos o que forneceu dados que ajudam a avaliação do estado nutricional

Study protocol for the multicentre cohorts of Zika virus infection in pregnant women, infants, and acute clinical cases in Latin America and the Caribbean: The ZIKAlliance consortium

Background: The European Commission (EC) Horizon 2020 (H2020)-funded ZIKAlliance Consortium designed a multicentre study including pregnant women (PW), children (CH) and natural history (NH) cohorts. Clinical sites were selected over a wide geographic range within Latin America and the Caribbean, taking into account the dynamic course of the ZIKV epidemic. Methods: Recruitment to the PW cohort will take place in antenatal care clinics. PW will be enrolled regardless of symptoms and followed over the course of pregnancy, approximately every 4 weeks. PW will be revisited at delivery (or after miscarriage/abortion) to assess birth outcomes, including microcephaly and other congenital abnormalities according to the evolving definition of congenital Zika syndrome (CZS). After birth, children will be followed for 2 years in the CH cohort. Follow-up visits are scheduled at ages 1-3, 4-6, 12, and 24 months to assess neurocognitive and developmental milestones. In addition, a NH cohort for the characterization of symptomatic rash/fever illness was designed, including follow-up to capture persisting health problems. Blood, urine, and other biological materials will be collected, and tested for ZIKV and other relevant arboviral diseases (dengue, chikungunya, yellow fever) using RT-PCR or serological methods. A virtual, decentralized biobank will be created. Reciprocal clinical monitoring has been established between partner sites. Substudies of ZIKV seroprevalence, transmissio

Genetic determinants of telomere length from 109,122 ancestrally diverse whole-genome sequences in TOPMed

Genetic studies on telomere length are important for understanding age-related diseases. Prior GWASs for leukocyte TL have been limited to European and Asian populations. Here, we report the first sequencing-based association study for TL across ancestrally diverse individuals (European, African, Asian, and Hispanic/Latino) from the NHLBI Trans-Omics for Precision Medicine (TOPMed) program. We used whole-genome sequencing (WGS) of whole blood for variant genotype calling and the bioinformatic estimation of telomere length in n = 109,122 individuals. We identified 59 sentinel variants (p < 5 × 10−9) in 36 loci associated with telomere length, including 20 newly associated loci (13 were replicated in external datasets). There was little evidence of effect size heterogeneity across populations. Fine-mapping at OBFC1 indicated that the independent signals colocalized with cell-type-specific eQTLs for OBFC1 (STN1). Using a multi-variant gene-based approach, we identified two genes newly implicated in telomere length, DCLRE1B (SNM1B) and PARN. In PheWAS, we demonstrated that our TL polygenic trait scores (PTSs) were associated with an increased risk of cancer-related phenotypes

Induction of somatic embryogenesis as an example of stress-related plant reactions

In this review, we address the role of stress as one of the principal causes for a cell or tissue to change its pre-existing somatic program, reprogramming itself to express the embryogenic pathway. The focus of this paper is the effect of different stress conditions on the induction phase of plant somatic embryogenesis, as well as the development of embryogenic competence as a result of the applied stresses. We also present a variety of data that link plant somatic embryogenesis, DNA methylation and oxidative stress response