Identification and characterization of the first pectin methylesterase gene discovered in the root lesion nematode Pratylenchus penetrans

Similar to other plant-parasitic nematodes, root lesion nematodes possess an array of enzymes that are involved in the degradation of the plant cell wall. Here we report the identification of a gene encoding a cell wall-degrading enzyme, pectin methylesterase PME (EC 3.1.1.11), in the root lesion nematode Pratylenchus penetrans. Both genomic and coding sequences of the gene were cloned for this species, that included the presence of four introns which eliminated a possible contamination from bacteria. Expression of the Pp-pme gene was localized in the esophageal glands of P. penetrans as determined by in situ hybridization. Temporal expression of Pp-pme in planta was validated at early time points of infection. The possible function and activity of the gene were assessed by transient expression of Pp-pme in plants of Nicotiana benthamiana plants via a Potato virus X-based vector. To our knowledge, this is the first report on identification and characterization of a PME gene within the phylum Nematoda

Perspectives on the use of plant growth promoting bacteria as biocontrol agents for the pine wilt disease

Pine Wilt Disease (PWD) has been considered one of the major threats affecting conifer forests and forestry economics throughout the whole world. This complex disease is caused by the pinewood nematode (PWN) Bursaphelenchus xylophilus, through an intricate interaction with other partners like nematode associated bacteria and an insect vector that is responsible for nematode tree-to-tree transportation and dissemination. The first report of PWD dates to 1905 in Japan. Later, the PWD spread out to China (1982) and Korea (1988). In Europe, PWD was firstly reported in Portugal in 1999. Since then the disease has spread throughout the country and recently new PWD focus were found in Madeira Island (2008) and Spain (2010), thus indicating an elevated risk to other European countries (including the Scandinavia region) and forestlands. Although efforts for controlling and understanding PWD have been made, till now there are no significant solutions rather than the destruction of infected trees and forestlands, leading to huge losses, i.e 26 million m3 of timber in Japan, which is both economic and ecologically unacceptable. Therefore, new solutions are needed in order to control PWD. Some of the disease control methods developed rely on the use of chemicals with nematicidal effects. Plant breeding programs are also being conducted in order to obtain resistant pine trees. Yet, these approaches can endure as also they can be non-environmental friendly. In other plant diseases caused by plant parasitic nematodes the use of plant growth promoting bacteria (PGPB) as biocontrol agents is considered to be an interesting and effective green-approach. In this sense, the results obtained in our lab indicate that the inoculation of Pinus pinaster (maritime pine) seedlings with PGPB leads to a reduction of PWD development, as also to an increased plant growth. These results suggest that the inoculation of pine seedlings with PGPB in a “nursery” system can be a useful alternative in obtaining PWN resilient pine trees

Life cycle assessment of biohydrogen produced from biogas

Tese de mestrado, Engenharia da Energia e Ambiente, 2023, Universidade de Lisboa, Faculdade de CiênciasHydrogen is a versatile and clean energy carrier that holds promise for a sustainable energy future. Steam methane reforming (SMR) and water electrolysis are two prominent pathways for hydrogen production. SMR can run on biogas instead of fossil natural gas, while water electrolysis, particularly proton exchange membrane (PEM) electrolysis, can rely on electricity from renewable energy sources. This study assesses these hydrogen production methods using a Life Cycle Assessment (LCA) approach, considering CO2eq emissions and demineralized water consumption. The Pedigree Matrix is employed to rank the quality of the results. DWSIM, a chemical processes simulation open-software is used in process simulation for the inventory of mass and energy flows. A sensitivity analysis is also performed to: SMR operating temperature, number of water-gas shift reactors, off-gas use as heat source, different IPCC (Intergovernmental Pannel on Climate Change) CO2 equivalency factors and different electricity generation mix. The findings contribute to a better understanding of hydrogen production from biogas by reforming in comparison to the other two methods by presenting higher needs of feedstock, intermediate water consumption and very low greenhouse gas (GHG) emissions

Protecting our crops – sustainable approaches for the control of plant-parasitic nematodes

Plant-parasitic nematodes (PPN) are a threat to global agriculture with losses estimated at 100 billion USD per year (Savary et al., 2019). Ranking 3rd as the most serious PPNs in agriculture, root- lesion nematodes (RLNs), Pratylenchus spp., are known by their worldwide distribution and broad host range (Jones et al., 2013). Pratylenchus penetrans is one of the most damaging RLN with over 400 hosts affecting economically important agronomic and horticultural crops (Castillo and Volvas, 2017). In Europe, P. penetrans has been detected in potato cultures and ornamental plants in Portugal and in association olive trees in Spain, Italy, and Turkey. This RLN is classified as an A1 quarantine pest in South America, while in EU, is a regulated A2 non-quarantine pest. Effective control measurements for RLN, and specifically for P. penetrans, are limited due to the lack of natural resistant varieties. The impact of P. penetrans alone and in interaction with other plant pathogens (e.g., bacteria and fungi) in such cultures emphasises an urgent demand for the development of new and sustainable control approaches as alternative to common agriculture chemicals. In this sense, the molecular mechanisms of P. penetrans parasitism are being investigated for the development of alternative and more specific control strategies (Vieira et al., 2019; Vicente et al., 2019)

Identification and characterization of the first pectin methylesterase gene discovered in the root lesion nematode Pratylenchus penetrans

Similar to other plant-parasitic nematodes, root lesion nematodes possess an array of enzymes that are involved in the degradation of the plant cell wall. Here we report the identification of a gene encoding a cell wall-degrading enzyme, pectin methylesterase PME (EC 3.1.1.11), in the root lesion nematode Pratylenchus penetrans. Both genomic and coding sequences of the gene were cloned for this species, that included the presence of four introns which eliminated a possible contamination from bacteria. Expression of the Pp-pme gene was localized in the esophageal glands of P. penetrans as determined by in situ hybridization. Temporal expression of Pp-pme in planta was validated at early time points of infection. The possible function and activity of the gene were assessed by transient expression of Pp-pme in plants of Nicotiana benthamiana plants via a Potato virus X-based vector. To our knowledge, this is the first report on identification and characterization of a PME gene within the phylum Nematoda

Is digital influencers’ content more effective than your brands’ in creating online brand related content?: The impact of perceptions regarding digital influencers as source of brand content on consumers’ purchase intention of beauty brands

The rise of social media content generated by consumers about beauty products/services has caught the attention of brands from that segment, where some consumers ascended to digital influencers - revealing to be effective in influencing purchase decisions. Considering this, beauty brands started to increasingly resource to influencers with that purpose. The question of whether this content creation by influencers is more effective in generating brand outputs than content created by the brand itself remains unanswered. The purpose of this study is to understand to what extent perceptions regarding digital influencers’ social media content have a stronger impact than perceptions regarding content created by brands in consumers’ both purchase intention and online engagement with the brand. The role of brand attitude was also analyzed in this context. 200 female respondents’ answers were analyzed through a questionnaire. The results showed that perceptions regarding content generated by influencers don’t have a stronger impact than perceptions regarding content created by brands on brand attitude and towards both consumers’ purchase intention and online engagement with beauty brands. However, brand attitude revealed to be positively correlated with both perceptions, also having a significant impact on consumers’ purchase intention and online engagement with the brand, thus, it was generally a strong mediator of effects. Consequently, brands should not replace their own social media content with content created by influencers but work together and include them in their social media strategy.O conteúdo criado nas redes sociais pelos consumidores sobre produtos/serviços de beleza captou a atenção das marcas desse segmento, onde alguns ascenderam a digital influencers - revelando-se eficazes em influenciar decisões de compra. Assim, as marcas de beleza começaram a recorrer a estes com esse propósito. A questão do conteúdo criado por influencers ser mais eficiente em gerar outputs para marca do que o conteúdo criado pela marca em si permanece por responder. O propósito deste estudo é perceber de que modo as perceções à cerca do conteúdo gerado por influencers tem um maior impacto do que as perceções à cerca do conteúdo criado pelas marcas na intenção de compra e na interação online com as marcas. O papel da atitude em relação à marca foi simultaneamente analisado neste contexto. As respostas de 200 respondentes do sexo feminino foram analisadas através de um questionário. Os resultados mostraram que as perceções em relação ao conteúdo gerado por influencers não têm um maior impacto que as perceções em relação ao conteúdo criado pelas próprias marcas em ambas a intenção de compra e na interação online com as marcas. No entanto, a atitude em relação à marca mostrou estar positivamente correlacionada com ambas as perceções, com um impacto significativo na intenção de compra e na interação online com as marcas, e, no geral, ter um forte efeito de mediação. Consequentemente, as marcas não devem substituir o seu conteúdo com o conteúdo criado por influencers, mas trabalhar em conjunto e incluí-los na sua estratégia

Pine wilt disease and red ring disease of coconut: opportunities and perspectives in the study of two nematodes Bursaphelenchus xylophilus and B. cocophilus.

The xylophagous nematodes Bursaphelenchus cocophilus and B. xylophilus (Nematoda: Parasitaphelenchidae), are causative agents of two serious diseases, “red ring disease” (RRD) with great importance to coconut and certain oil palm species in Central and South America, and in “pine wilt disease” (PWD), which has wreaked havoc in forest areas in the Far East and now more recently in Europe (Portugal and Spain). PWD has not yet been detected in Brasil or any other country in Central or South America, but there is great risk of introduction due to worldwide movement of wood and wood products through major sea ports. Recently, for example, wood shipments originating from Brasil, infested with B. xylophilus, have been intercepted in China. Due to the taxonomical proximity between these two nematodes (the only two plant pathogenic species within the genus Bursaphelenchus, containing nearly 100 species), the similarity of life cycles (with the insect vectors Rhynchophorus palmarum for B. cocophilus and Monochamus spp. for B. xylophilus) and the likely genomic and proteomic similarities, a comparative study between these two nematodes may provide important insights into understanding RRD, in particular through the genome sequencing of B. cocophilus, and comparison with the recently sequenced genome of B. xylophilus. Knowledge on specific pathogenicity genes, involved in the RRD process, combined with past and present knowledge, should be helpful in designing new and effective control methods for this major tropical disease of coconut and palm

Are Bursaphelenchus xylophilus-associated bacteria playing a role in pine wilt disease?

Pine wilt disease (PWD), presently the most severe coniferous disease worldwide, is caused by the plant parasitic nematode Bursaphelenchus xylophilus, the pinewood nematode (PWN). Although PWN is considered the major pathogenic factor in PWD, its associated bacterial community is not ruled out as potential helpers in this complex and still little understood disease. This work presents the characterization of PWN-associated bacteria and plant pathogenicity trials in the pine host Pinus pinaster. The 16S rRNA gene sequencing of PWN-associated bacteria revealed the presence of bacteria from two phyla Proteobacteria (Burkholderiales, Pseudomonadales, Enterobacteriales and Xanthomonadales) and Firmicutes (Lactobacillales and Bacilalles). Phenotypic characterization revealed the presence of a heterogeneous bacterial community associated with PWN, exhibiting plant pathogenic traits common in wilting diseases. Our results suggest the intriguing possibility that some PWN-associated bacteria may play a significant role in the development of PWD

As motivações do turista de aventura e a imagem dos destinos

O turismo de aventura é entendido como a deslocação de pessoas para espaços naturais, motivadas pela atração, pelo desconhecido e pela vontade de enfrentar situações de desafio físico e emocional (Beni, 2003). Este tipo de turismo impulsiona a prática de atividades físicas, que tem por intuito abranger emoções e riscos controlados, obrigando a técnicas e equipamentos particulares, garantindo a segurança de quem o pratica (Fernandes, 1998). O objetivo deste trabalho em progresso é analisar o perfil dos turistas de aventura na região Centro de Portugal, especificamente estudar as variáveis de motivação, risco e imagem. Pretende-se avaliar os diversos aspetos e elementos inerentes à prática deste tipo de turismo: o que motiva e influencia os turistas para o seu consumo, avaliar o risco como fator motivacional, bem como a imagem que um turista tem de um destino de aventura e de si mesmo após o consumo do produto.info:eu-repo/semantics/publishedVersio

Heterogeneous microbial community associated with Bursaphelenchus xylophilus

Pine wilt disease (PWD) is a complex disease integrating three major factors: the causal agent, the pinewood nematode Bursaphelenchus xylophilus; the insect-vector Monochamus spp.; and the host pine tree, Pinus sp. Since the early 80’s, the notion that another pathogenic agent involved, namely bacteria, may play a role in PWD has been gaining traction, however the role of bacteria in PWD is still unknown. The present work suggests the intriguing possibility that some B. xylophilus-associated bacteria may play a significant role in the development of this disease. This is inferred as a consequence of: (i) the phenotypic characterization, of a collection of 35 isolates of B. xylophilus-associated bacteria, in different tests broadly used to test plant pathogenic and plant growth promoting bacteria, and (ii) greenhouse experiments that infer pathogenicity of these bacteria in in maritime pine, Pinus pinaster. The results illustrate the presence of a heterogeneous microbial community associated with B. xylophilus and the traits exhibited by at least some of these bacteria appear to be related to PWD symptoms. The inoculation of four specific B. xylophilus-associated bacteria in P. pinaster seedlings resulted in the development of some PWD symptoms suggesting that these bacteria likely play an active role with B. xylophilus in PWD