62 research outputs found

    Isolation and characterization of cgchi3, a nodule-specific gene from Casuarina glauca encoding a class III chitinase

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    Chitinases (EC 3.2.1.14) catalyse the hydrolysis of chitin, a homopolymer of b-1,4-linked N-acetyl-D-glucosamine residues. Plant chitinases are involved in a wide variety of processes; in particular, their expression has been found to be enhanced in symbiotic and pathogenic plant–microbe interactions. During this work we have cloned and characterized a gene encoding a class III chitinase from actinorhizal nodules of Casuarina glauca (cgchi3). CGCHI3 was found to be encoded by a single gene that was specifically activated in nodules as compared with uninoculated control roots and leaves. The expression of this gene was further enhanced in nodules after salicylic acid treatment and completely repressed after wounding. In situ hybridisation analysis revealed that cgchi3 is an early nodulin gene, being expressed in the meristem and in the uninfected cortical cells of young nodules. Based on the obtained results we suggest that this gene is involved in nodule development. This is the first report on a class III chitinase coding gene that is specifically activated during actinorhizal symbiosis.info:eu-repo/semantics/publishedVersio

    Olive tree (Olea europaea L.) diversity in traditional small farms of Ficalho, Portugal

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    The genetic diversity of “Gama” and “Bico de Corvo”, local cultivars of olive tree (Olea europaea) from seven traditional orchards of Ficalho (Alentejo region, Portugal), was studied to characterize the local diversity and assess the level of on farm diversity. Two different analytical systems were used: endocarp morphological characteristics and genetic analysis by microsatellite markers (Simple Sequence Repeats or SSR). The seven screened loci were polymorphic and allowed the identification of 23 distinct SSR profiles within the 27 trees analyzed. A total of 52 different alleles were scored, with an average of 7.43 alleles/SSR locus, and considerable genetic diversity was found. Neighbor-Joining algorithm cluster analysis and principal co-ordinate analysis (PCoA) allowed for the identification of the genetic relationships between several accessions. The 27 Olea accessions were clearly separated into three different groups. SSR analysis was more precise than endocarp characterization in the classification of genetic diversity among the olive tree cultivars. The study shows reasonable olive tree diversity in Ficalho, indicating that these traditional orchards are important reservoirs of old minor cultivars and incubators of new genotypesinfo:eu-repo/semantics/publishedVersio

    Experimental Frog Virus 3 infection using Brazilian strain: amphibians susceptibility

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    Um número alarmante de notificações globais sobre surtos de mortalidade de anfíbios tem sido realizado nos últimos anos. As doenças emergentes destacam-se como as principais causas potenciais. O ranavírus é uma doença altamente infecciosa disseminada em todo o mundo, capaz de afetar até outros animais ectotérmicos como peixes e répteis. Uma questão importante em relação a essa patologia é a falta de sinais clínicos antes de levar à morte. Com o objetivo de compreender melhor a suscetibilidade dos anuros, o presente trabalho analisou a taxa de sobrevivência de rãs-touro (Lithobates catesbeianus), desafiadas com três doses de uma estirpe brasileira do Frog virus 3 (FV3). A análise de qPCR indicou baixa taxa de infectividade nesses animais, tanto como larvas quanto como adultos. Procurando esclarecer os resultados, foram formuladas as seguintes hipóteses: 1) A quantidade de inóculo aplicada nas rãs foi insuficiente para desencadear uma infecção; 2) Para que o FV3 dê sinais clínicos nesta espécie, é necessário um cofator; 3) Os animais sofreram infecção por FV3, mas se recuperaram no decorrer do experimento, e 4) O inóculo utilizado pode ter sido de baixa virulência. Finalmente, foi discutida a presença de sinais clínicos reais de ranavírus e levantada a hipótese mais provável.An alarming number of global warnings concerning amphibian mortality outbreaks have been released in recent years. Emerging diseases stand out as the main potential causes. Ranavirus is a worldwide-spread highly infectious disease capable of affecting even other ectothermic animals such as fish and reptiles. One major issue regarding this pathology is the lack of clinical signs before it leads up to death. Aiming at having a better understanding of anurans susceptibility, this study analyzed bullfrog (Lithobates catesbeianus) survival rate, when challenged with three doses of a Brazilian strain of Frog Virus 3 (FV3). The qPCR analysis indicated a low infectivity rate in these animals both as larvae and as adults. To elucidate the results, the following hypothesis was performed: 1) The amount of inoculum used on the frogs was insufficient to trigger an infection; 2) For the FV3 to produce clinical signs in this species, there is the need for a cofactor; 3) The animals did undergo FV3 infection but recovered in the course of the experiment, and 4) The inoculum utilized might have been low-virulence. Finally, the presence of actual clinical signs of ranavirus is discussed, with the more likely hypothesis

    La importancia de la calificaciĂłn de los recursos humanos en turismo: un estudio aplicado a las agencias de viajes en Portugal

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    El turismo se ha consolidado como uno de los sectores económicos más importantes y de más rápido crecimiento del mundo. El éxito de esta actividad económica depende, en gran medida, de recursos humanos cualificados. En el caso de las agencias de viajes y turismo (AVT), las agencias de viajes (AV) son el pilar fundamental de toda la dinámica de este subsector. Dado que no existen muchos estudios específicos sobre estos profesionales y sus niveles de cualificación y satisfacción laboral, este artículo tiene como objetivo definir un perfil del agente de viajes en Portugal, pudiendo dividirlo en cuatro elementos: sociodemográfico, profesional, económico y psicológico, y comprender la influencia del nivel de cualificación. Se utilizó una metodología descriptiva cuantitativa con análisis univariado y bivariado, utilizando la recolección de datos primarios basada en la encuesta por cuestionario a un número significativo de agentes de viajes que trabajan en Portugal, representativo del espesor territorial nacional. Los resultados empíricos de este estudio nos permitieron concluir, en términos generales, que la gran mayoría de los agentes de viajes cuentan con títulos de educación superior con impacto en la zona. Los agentes de viajes con más años en la profesión tienden a ganar mejores salarios, aunque los agentes de grupos de mayor edad muestran una menor cualificación formativa. Sin embargo, también se concluye que las mejores cualificaciones académicas de los agentes de viajes no suponen necesariamente una mayor remuneración; del mismo modo, los agentes de viajes con el grado de turismo se sienten menos satisfechos con la profesión como consecuencia de una remuneración inadecuada y altos niveles de estrés.Tourism has established itself as one of the most important and fastest growing economic sectors in the world. The success of this economic activity depends heavily on qualified human resources. In the case of travel agencies and tourism, travel agents are the pillar of all the dynamics of this subsector. In the absence of many specific studies on these professionals and their levels of qualification and job satisfaction, this article aims to define a profile of the travel agent in Portugal, by dividing it into four elements: socio‑demographic, professional, economic and psychological and also to understand the influence of the level of qualification. A descriptive quantitative methodology with univariate and bivariate analysis was applied using primary data collection, based on the questionnaire survey of a significant number of travel agents operating in Portugal, representative of the national territorial density. The empirical results of this study allowed the general conclusion that the vast majority of travel agents have higher education qualifications with incidence in the area. Travel agents with more years of profession tend to earn better wages, although agents in higher age brackets show lower educational qualifications. However, it is not because travel agents have more education that they will get better pay; such as travel agents with a degree in tourism feel less satisfied with their profession, this correlates with inappropriate pay and high levels of stress

    Lack of detectable allergenicity of transgenic maize and soya samples

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    Background: The safety issues regarding foods derived from genetically modified (GM) plants are central to their acceptance into the food supply. The potential allergenicity of proteins newly introduced in GM foods is a major safety concern. Objective: We sought to monitor, in potentially sensitive human populations, the allergenicity effects of 5 GM materials obtained from sources with no allergenic potential and already under commercialization in the European Union. Methods: We have performed skin prick tests with protein extracts prepared from transgenic maize (MON810, Bt11, T25, Bt176) and soya (Roundup Ready) samples and from nontransgenic control samples in 2 sensitive groups: children with food and inhalant allergy and individuals with asthmarhinitis. We have also tested IgE immunoblot reactivity of sera from patients with food allergy to soya (Roundup Ready) and maize (MON810, Bt11, Bt176) samples, as well as to the pure transgenic proteins (CryIA[b] and CP4 5-enolpyruvylshikimate- 3-phosphate synthase). Results: None of the individuals undergoing tests reacted differentially to the transgenic and nontransgenic samples under study. None of the volunteers tested presented detectable IgE antibodies against pure transgenic proteins. Conclusion: The transgenic products under testing seem to be safe in terms of allergenic potential. We propose postmarket testing as an important screening strategy for putative allergic sensitization to proteins introduced in transgenic plants.Supported by Fundação Calouste Gulbenkian, research project SDH.SP.I.01.11 and by Comissão de Fomento da Investigação em Cuidados de Saúde, research project no. 186/0

    Genetic Diversity and Population Structure of Wild Beets (Beta spp.) from the Western Iberian Peninsula and the Azores and Madeira Islands

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    In this work, using simple sequence repeat (SSR) markers, we present new insights into the genetic diversity, differentiation, and structure of Beta vulgaris subsp. maritima of western Iberia and the Azores and Madeira islands and of B. macrocarpa from southern Portugal. B. macrocarpa occurs only in southern Portugal and frequently in sympatry with B. vulgaris subsp. maritima, showing genetic introgression. B. macrocarpa has a better-defined structure than B. vulgaris subsp. maritima, which has a high degree of admixture. A great differentiation (FST ranging from 0.277 to 0.184) was observed among the northern populations of B. vulgaris subsp. maritima. In contrast, only a small differentiation (FST ranging from 0.000 to 0.026) was detected among the southern B. vulgaris subsp. maritima populations. The inland B. vulgaris subsp. maritima populations (“RIO” and “VMT”) are distinct from each other, which also occurs with the two islands’ populations (“MAD” and “AZO”). The existence of two distinct Atlantic Sea currents can explain the fact that Madeira is related to the southern populations, while the Azores is related to the northern populations. We consider that understanding the relationships existing within Beta spp. is key to future genetic studies and for the establishment of conservation measures. Our results show that the southern coastal areas of Portugal should be considered as a potential site for in situ conservation of the beet wild relatives. Special attention is needed in what concerns B. macrocarpa because this is a rare species that also occurs in a sympatric relationship with B. vulgaris subsp. maritimainfo:eu-repo/semantics/publishedVersio

    Population structure in Quercus suber L. revealed by nuclear microsatellite markers

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    Quercus suber L. is a sclerophyllous tree species native to the western Mediterranean, a region that is considered highly vulnerable to increased temperatures and severe dry conditions due to environmental changes. Understanding the population structure and demographics of Q. suber is essential in order to anticipate whether populations at greater risk and the species as a whole have the genetic background and reproductive dynamics to enable rapid adaptation. The genetic diversity of Q. suber has been subject to different studies using both chloroplast and nuclear data, but population structure patterns remain unclear. Here, we perform genetic analyses on Q. suber using 13 nuclear microsatellite markers, and analysed 17 distinct locations across the entire range of the species. Structure analyses revealed that Q. suber may contain three major genetic clusters that likely result from isolation in refugia combined with posterior admixture and putative introgression from other Quercus species. Our results show a more complex structure scenario than previously inferred for Q. suber using nuclear markers and suggest that different southern populations contain high levels of genetic variation that may contribute to the resilience of Q. suber in a context of environmental change and adaptive pressureinfo:eu-repo/semantics/publishedVersio

    Haplotype diversity patterns in Quercus suber (Fagaceae) inferred from cpDNA sequence data

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    Chloroplast genome diversity in cork oak (Quercus suber) is characterised by the occurrence of haplotypes that are akin to those found in other Mediterranean oak species, particularly in Q. ilex and Q. rotundifolia, suggesting the possible presence of an introgressed chloroplast lineage. To further investigate this pattern, we reconstructed chloroplast haplotypes by sequencing four chloroplast markers (cpDNA), sampled across 181 individuals and 10 taxa. Our analyses resulted in the identification of two diversified chloroplast haplogroups in Q. suber, corresponding to a geographically widespread lineage and an Afro-Iberian lineage. Time-calibrated phylogenetic analyses of cpDNA point to a Miocene origin of the two haplogroups in Q. suber, suggesting that the Afro-Iberian lineage was present in cork oak before the onset of glaciation periods. The persistence of the two haplogroups in the western part of the species distribution range may be a consequence of either ancient introgression events or chloroplast lineage sorting, combined with different fixation in refugia through glaciation periods. Our results provide a comprehensive insight on the origins of chloroplast diversity in these ecologically and economically important Mediterranean oaks.info:eu-repo/semantics/publishedVersio

    Haplotype diversity patterns in Quercus suber (Fagaceae) inferred from cpDNA sequence data

    Get PDF
    Chloroplast genome diversity in cork oak (Quercus suber) is characterised by the occurrence of haplotypes that are akin to those found in other Mediterranean oak species, particularly in Q. ilex and Q. rotundifolia, suggesting the possible presence of an introgressed chloroplast lineage. To further investigate this pattern, we reconstructed chloroplast haplotypes by sequencing four chloroplast markers (cpDNA), sampled across 181 individuals and 10 taxa. Our analyses resulted in the identification of two diversified chloroplast haplogroups in Q. suber, corresponding to a geographically widespread lineage and an Afro-Iberian lineage. Time-calibrated phylogenetic analyses of cpDNA point to a Miocene origin of the two haplogroups in Q. suber, suggesting that the Afro-Iberian lineage was present in cork oak before the onset of glaciation periods. The persistence of the two haplogroups in the western part of the species distribution range may be a consequence of either ancient introgression events or chloroplast lineage sorting, combined with different fixation in refugia through glaciation periods. Our results provide a comprehensive insight on the origins of chloroplast diversity in these ecologically and economically important Mediterranean oaks.info:eu-repo/semantics/publishedVersio
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