Imbibition, germination, and early seedling growth responses of light purple and yellow seeds of red clover to distilled water, sodium chloride, and nutrient solution

The seeds of red clover are heteromorphic and two color morphs can be visually recognized, light purple and yellow, resulting from heterozygosity and recessive homozygosity at two loci. Here, we report the responses of seed imbibition, seed germination, and early seedling growth of the two morphs to distilled water, sodium chloride, and complete nutrient solution. The sensitivity of red clover seeds to treatments increased with the stage of development in what seems to be a cumulative process. No differences were found in seed imbibition between morphs or between treatments. In seedling growth, on the contrary, treatments were always effective, but differences between morphs were only observed in seeds that were treated with nutrient solution, whereas in the intermediate stage of seed germination, the effects by treatments were observed together with the appearance of differences between morphs in distilled water and in the treatment by sodium chloride solution. Simultaneously, the superior performance of the yellow morph that was found in germination, which appears to be a trait stable across cultivars of red clover seeds, turned into a superior performance of the light purple morph in seedling growth

Effects of dark or of red, blue or white light on germination of subterranean clover seeds

Dry or imbibed seeds of the negatively photoblastic burr burying subterranean clover cv. ‘Seaton Park’ were treated with dark or with red, blue or white light to evaluate the effects of light on seed germination. Dry seeds treated with constant white light, red light or blue light during 8 days and subsequently incubated in dark had final germination and duration of germination reduced, and the distribution of germination changed from highly asymmetric to symmetric respectively. Imbibing seeds incubated under constant blue or white light had final germination strongly reduced seven days after sowing (7.3% and 50.1% of the germination under dark) with significant differences between them. After transferral to dark, true complete recovery of germination of seeds treated with white light was observed 19 days after sowing, but only partial recovery in seeds treated with blue light. Results of dry and imbibed seeds are consistent with no activity of phytochromes, as expected in negatively photoblastic seeds. Results of dry seeds are seemingly contradictory because total germination data imply the inactivity of red and blue light photoreceptors, the opposite being implied by duration and shape of germination. A tentative hypothetical solution for the contradiction is presented. Results of imbibed seeds are fully consistent with cryptochromes but not with phototropins mediation of responses to light of seed germination in ‘Seaton Park’. The ecological and adaptive significance of such responses are discussed in the framework of light attenuation in soil and the requirement and ability of subterranean clover ‘Seaton Park’ to bury seeds

GENETIC STUDY OF BIOMARKERS INVOLVED IN THE PROCESS OF AGING NEURODEGENERATION

Synaptosomal-associated protein of 25kDa (SNAP-25) is an age-regulated vesicular SNARE protein involved in the exocytosis of neurotransmitters from synapses, a process that is altered in Alzheimer\u2019s disease (AD). Changes in SNAP-25 levels are suggested to contribute to age-related decline of cognitive function, and single nucleotide polymorphisms (SNPs) in the SNAP-25 gene are present in neuropsychiatric conditions and play a role in determining IQ phenotypes. To verify a possible role of SNAP-25 in AD we analyzed five gene polymorphisms in patients with AD (N=607), replicating the study in subjects with amnestic mild cognitive impairment (aMCI)(N=154) and in two groups of age-matched healthy controls (HC1: N=615 and HC2: N=310). Results showed that the intronic rs363050(A) and rs363043(T) alleles, as well as the rs363050/rs363043 A-T haplotype are significantly more frequent in both AD and aMCI. Further analyses indicated that these alleles and haplotype are associated with pathological scores of categorical fluency in AD alone. Finally, SNAP-25 genotypes correlated with a significantly decreased brain activity in the cingulate cortex and in the frontal (middle and superior gyri) and the temporo- parietal (angular gyrus) area, as measured by fMRI. SNAP-25 polymorphisms are associated with AD and correlate with alterations in categorical fluency and a reduced localized brain activity. In conclusion SNAP-25 polymorphisms could be suggested as surrogate markers for the diagnosis of AD and of cognitive deficit; these SNPs might also have a possible predictive role in the natural history of AD. Moreover we investigated a possible correlations between APOE4 and SNAP-25 polymorphisms and the outcome of a multidimensional cognitive, behavioral and functional stimulation (MST). Fifty-eight individuals with mild-to-moderate AD underwent MST for 10 weeks. Mini Mental Scale Evaluation (MMSE), Functional Living Skills Assessment (FLSA) and Neuropsychiatric Inventory scale (NPI) were performed at baseline and after therapy. Molecular genotyping of ApoE4 and SNAP-25 SNPs were correlated with \u394MMSE, \u394NPI and \u394FLSA scores by multinomial logistic regression analysis. Results shown higher overall MMSE scores after rehabilitation in ApoE4 negative compared to ApoE4 positive patients, whereas the SNAP-25 rs363050(G) and rs363039(A) alleles correlated specifically with significant improvements in behavioural parameters after MST. Haplotype analysis of rs363050, rs363039 and rs363043 SNAP-25 SNPs showed the presence of a significant association between SNAP-25 haplotypes and lower \u394NPI. In particular the rs363050(G)-rs363039(A)-rs363043(C): (GAC) haplotype was statistically associated with a better outcome of treatment as measured by the NPI scale. In conclusion polymorphisms in genes known to modulate neural plasticity may predict the outcome of a multistructured rehabilitation protocol in AD

História da fitovirologia no Brasil

O presente trabalho é uma revisão histórica sucinta da atuação de fitopatologistas, fitovirologistas e outros técnicos no Brasil na área das viroses de plantas. É considerado que a estrutura atual da pesquisa fitovirológica existente a nível federal ou estadual no país é suficiente para enfrentar problemas representados pelas viroses de nossas culturas. Mas é apontado que há falta de uns poucos centros de pesquisa básica com vírus de plantas independentemente de considerações econômicas de problemas existentes. É mencionado que há dificuldade. em obter recursos para qualquer instituição ou grupo que trabalhe em pesquisas mais básicas e que essas são melhor adaptadas a uma universidade ou instituto altamente especializado

Discondroplasia da tíbia como modelo em estudos de mecanobiologia experimental

A discondroplasia da tíbia, consiste numa anomalia espontânea, ou induzida, nas placas de crescimento epifisárias dos ossos longos, das estirpes de rápido crescimento das espécies avícolas, caracterizada pelo aparecimento de uma massa cartilagínea avascular opaca, não calcificada, que se estende até à metáfise, numa zona em que, normalmente, existe osso trabecular. Do ponto de vista citológico, a discondroplasia reflecte alterações na homeostase celular no decurso normal da ossificação endocondral, ou seja, a cartilagem não calcifica e não é substituída por osso endocondral. Deste modo, os processos de proliferação dos condrócitos (que é normal) e de degradação da cartilagem (que não se verifica), não estão em equilíbrio, resultando numa acumulação de matriz extracelular. Com a presente linha de investigação pretende-se, com base em resultados obtidos por um dos autores [Capela e Silva, 2004], designadamente no que diz respeito à expressão das caderinas, e com base noutros trabalhos relativos à expressão de proteínas de stress [Ribeiro e tal., 2004], avaliar da possibilidade de utilização da discondroplasia em estudos de mecanobiologia experimental

DNA vaccines against dengue virus based on the ns1 gene: The influence of different signal sequences on the protein expression and its correlation to the immune response elicited in mice

AbstractWe analyzed four DNA vaccines based on DENV-2 NS1: pcENS1, encoding the C-terminal from E protein plus the NS1 region; pcENS1ANC, similar to pcENS1 plus the N-terminal sequence from NS2a (ANC); pcTPANS1, coding the t-PA signal sequence fused to NS1; and pcTPANS1ANC, similar to pcTPANS1 plus the ANC sequence. The NS1 was detected in lysates and culture supernatants from pcTPANS1-, pcENS1- and pcENS1ANC-transfected cells and not in cells with pcTPANS1ANC. Only the pcENS1ANC leads the expression of NS1 in plasma membrane, confirming the importance of ANC sequence for targeting NS1 to cell surface. High levels of antibodies recognizing conformational epitopes of NS1 were induced in mice immunized with pcTPANS1 and pcENS1, while only few pcENS1ANC-inoculated animals presented detectable anti-NS1 IgG. Protection against DENV-2 was verified in pcTPANS1- and pcENS1-immunized mice, although the plasmid pcTPANS1 induced slight higher protective immunity. These plasmids seem to activate distinct patterns of the immune system

Spirulina does not decrease muscle damage nor oxdidative stress in cycling athletes with adequate nutritional status

The objective of this study was to assess the effect of Spirulina maxima on oxidative stress and muscle damage in cycling athletes subjected to high volume and intensity of training. Eighteen male athletes were randomly divided into an experimental group (n=11) with age 27.8±3.5 and placebo (n=7) with age 34.3±2.3 in a double-blind fashion. They carried out a protocol of Spirulina dietary supplementation (7.5 g/day) of placebo for four weeks and maintained their trainings during this period. A nutritional anamnesis was performed and blood tests were done to determine pre and post levels of creatine kinase (CK), lactic dehydrogenase (LHD), superoxide dismutase (SOD) and malondialdehyde (MDA). The supplemented and placebo groups performed the same volume training, has adequate macronutrients and antioxidant vitamins ingestion before study, as well as initial CK, LDH, SOD and MDA levels. Supplementation did not promote a significant alteration in CK levels on supplemented group (158.4±16.3 for 140.0±16.6 U/l, p>0.05), LDH (420±13.2 for 394.9±27.9 UI/l, p>0.05), MDA (2.8±0.2 for 2.9±0.4 nmol/ml, p>0.05), nor an increase in the SOD (7.3±0.6 for 7.0±0.6 U/mg Hb, p>0.05). We conclude that administration of Spirulina does not interfere in the magnitude of muscle damage nor in antioxidant status of cycling athletes that practice intense training

Lichen xanthones as models for new antifungal agents

Due to the emergence of multidrug-resistant pathogenic microorganisms, the search for new antimicrobial compounds plays an important role in current medicinal chemistry research. Inspired by lichen antimicrobial xanthones, a series of novel chlorinated xanthones was prepared using five chlorination methods (Methods A–E) to obtain different patterns of substitution in the xanthone scaffold. All the synthesized compounds were evaluated for their antimicrobial activity. Among them, 3-chloro-4,6-dimethoxy-1-methyl-9H-xanthen-9-one 15 showed promising antibacterial activity against E. faecalis (ATCC 29212 and 29213) and S. aureus ATCC 29213. 2,7-Dichloro-3,4,6-trimethoxy-1-methyl-9H-xanthen-9-one 18 revealed a potent fungistatic and fungicidal activity against dermatophytes clinical strains (T. rubrum, M. canis, and E. floccosum (MIC = 4–8 µg/mL)). Moreover, when evaluated for its synergistic effect for T. rubrum, compound 18 exhibited synergy with fluconazole (ΣFIC = 0.289). These results disclosed new hit xanthones for both antibacterial and antifungal activity.This work was partially supported through national funds provided by FCT/MCTES - Foundation for Science and Technology from the Ministry of Science, Technology, and Higher Education (PIDDAC) and the European Regional Development Fund (ERDF) through the COMPETE - Programa Operacional Factores de Competitividade (POFC) programme, under the Strategic Funding UID/Multi/04423/2013, the projects POCI-01-0145-FEDER-028736 and POCI-01-0145-FEDER-016790 (PTDC/MAR-BIO/4694/2014; 3599-PPCDT) in the framework of the programme PT2020, as well as by the project INNOVMAR - Innovation and Sustainability in the Management and Exploitation of Marine Resources (reference NORTE-01-0145-FEDER-000035, within Research Line NOVELMAR), supported by North Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). Diana I. S. P. Resende also acknowledge for her grant (NOVELMAR/BPD_2/2016-019) and Patrícia Pereira-Terra for her grant (NOVELMAR/BPD/2017/012)

The Syntaxin-1A gene single nucleotide polymorphism rs4717806 associates with the risk of ischemic heart disease

Ischemic heart disease (IHD) has a genetic predisposition and a number of cardiovascular risk factors are known to be affected by genetic factors. Development of metabolic syndrome and insulin resistance, strongly influenced by lifestyle and environmental factors, frequently occur in subjects with a genetic susceptibility. The definition of genetic factors influencing disease susceptibility would allow to identify individuals at higher risk and thus needing to be closely monitored.To this end, we focused on a complex of soluble-N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs), playing an important role in metabolic syndrome and insulin resistance, involved in endothelial dysfunction and heart disease. We assessed if genetic variants of the SNARE genes are associated with IHD.SNAP25 rs363050, Stx-1A rs4717806, rs2293489, and VAMP2 26bp ins/del genetic polymorphisms were analyzed in a cohort of 100 participants who underwent heart surgery; 56 of them were affected by IHD, while 44 were not. A statistical association of plasma glycemia and insulin resistance, calculated as Triglyceride glucose (TyG) index, was observed in IHD (P<.001 and P=.03, respectively) after binomial logistic stepwise regression analysis, adjusted by age, gender, diabetes positivity, waist circumference, and cholesterol plasma level. Among genetic polymorphisms, rs4717806(A) and rs2293489(T), as well as the rs4717806 - rs2293489 (A-T) haplotype were associated with higher risk for IHD (Pc=.02; Pc=.02; P=.04, respectively). Finally, a statistical association of rs4717806(AA) genotype with higher TyG index in IHD patients (P=.03) was highlighted by multiple regression analysis considering log-transformed biochemical parameters as dependent variable and presence of coronary artery disease, age, gender, waist circumference, presence of diabetes as predictors. These results point to a role of the Stx-1A rs4717806 SNP in IHD, possibly due to its influence on Stx-1A expression and, as a consequence, on insulin secretion and glucose metabolism

Large phenotype jumps in biomolecular evolution

By defining the phenotype of a biopolymer by its active three-dimensional shape, and its genotype by its primary sequence, we propose a model that predicts and characterizes the statistical distribution of a population of biopolymers with a specific phenotype, that originated from a given genotypic sequence by a single mutational event. Depending on the ratio g0 that characterizes the spread of potential energies of the mutated population with respect to temperature, three different statistical regimes have been identified. We suggest that biopolymers found in nature are in a critical regime with g0 in the range 1-6, corresponding to a broad, but not too broad, phenotypic distribution resembling a truncated Levy flight. Thus the biopolymer phenotype can be considerably modified in just a few mutations. The proposed model is in good agreement with the experimental distribution of activities determined for a population of single mutants of a group I ribozyme.Comment: to appear in Phys. Rev. E; 7 pages, 6 figures; longer discussion in VII, new fig.