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Publications

Involvement of the beta-cinnamomin elicitin in infection and colonisation of cork oak roots by Phytophthora cinnamomi

Publication . Cravador, A.; Horta, Marília; Caetano, P.; Medeira, C.; Maia, I.

The virulence of two wild type (PA45 and PA37) and two genetically modified (13C: hygromycin resistant; FATSS: hygromycin resistant and β-cin knock-down) Phytophthora cinnamomi strains towards cork oak (Quercus suber) was assessed via a quantitative evaluation of disease symptoms arising from a soil infestation assay, and by a istological analysis of root colonization. Comparison of virulence, as expressed by symptom severity, resulted in the following ranking: highly virulent (wild type strains), medium virulence (strain 13C) and weakly virulent (FATSS). Both transgenic strains were compromised in their virulence, as expressed by symptom severity, but strain 13C was much less affected than FATSS. Microscopic observation showed that the FATSS strain was unable to effectively invade the root, while 13C and the two wild type strains were all able to rapidly colonize the whole root, including the vascular tissue. These results strengthen the notion that elicitins are associated, either directly or indirectly, with the infection process of Phytophthora.

2010Journal article

Open access

Cloning, characterization and in vitro and in planta expression of a glucanase inhibitor protein (GIP) of Phytophthora cinnamomi

Publication . Martins, I.; Martins, F.; Belo, H.; Vaz, M.; Carvalho, M.; Cravador, A.; Choupina, A.

Oomycetes from the genus Phytophthora are fungus-like plant pathogens that are devastating for agriculture and natural ecosystems. They are able to secrete a glucanase inhibitor protein (GIP) that inhibits the activity of endoglucanases (EGases) involved in defense responses against infection. One of the most widely distributed and aggressive Phytophthora species, with more than 1,000 host plants is P. cinnamomi. In this work we report the sequencing and characterization of a class of GIPs secreted by Phytophthora cinnamomi. The gip gene from P. cinnamomi has a 937 bp ORF encoding a putative peptide of 312 deduced amino acids. The expression of this gene was studied during growth in different carbon sources (glucose, cellulose and sawdust), by RT-qPCR and its level of expression was evaluated at five time points. The highest expression of gip gene occurred in sawdust at 8 h of induction. In vivo infection of C. sativa revealed an increase in gip expression from 12 to 24 h. At 36 h its expression decreased suggesting that a compensatory mechanism must occur in plant.

2014Journal article

Restricted access

Cloning, characterization, in vitro and in planta expression of a necrosis-inducing Phytophthora protein 1 gene npp1 from Phytophthora cinnamomi

Publication . Martins, Ivone M.; Meirinho, Sofia; Costa, Rodrigo; Cravador, Alfredo; Choupina, Altino

The soil-borne oomycete Phytophthora cinnamomi is a highly destructive Phytophthora species associated with the decline of forest. This pathogen secretes a novel class of necrosis-inducing proteins known as Nep1-like proteins (NLPs). In this work, we report the sequencing and molecular characterization of one of these proteins, more specifically the necrosis-inducing Phytophthora protein 1 (NPP1). The ORF of the npp1 gene (EMBL database AM403130) has 768 bp encoding a putative peptide of 256 amino acids with a molecular weight of approximately 25 kD. In order to understand its function, in vitro gene expression was studied during growth in different carbon sources (glucose, cellulose, and sawdust), and at different times of infection, in vivo by RT-qPCR. The highest expression of the npp1 gene occurred in glucose medium followed by sawdust. In vivo infection of Castanea sativa roots with P. cinnamomi revealed a decrease in npp1 expression from 12 to 24 h; at 36 h its expression increased suggesting the existence of a complex mechanism of defense/attack interaction between the pathogen and the host. Expression of recombinant npp1 gene was achieved in Pichia pastoris and assessed by SDS-PAGE analysis of the protein secreted into the culture supernatant, revealing the presence of the NPP1 protein.

2019Journal article

Restricted access

Relatório de actividade profissional

Publication . Veiga , Joana Mira Nunes Seixas; Teodósio, Maria A.

This report aims at describing my professional experience and demonstrating the competences developed between 2008 and 2016, after conclusion of the degree in Marine Biology and Fisheries from the University of Algarve, in order to obtain the Master Degree in Marine Biology (“Despacho reitoral 033/2011: Licenciados Pré-Bolonha"). For almost 8 years, I have been employed by the Coastal & Marine Union (EUCC), in the Netherlands, one of the largest international associations dedicated to coastal and marine conservation and sustainable management. During this period, I gained extensive experience on project design, management and implementation but also communication activities and participatory approaches. I worked specifically on topics such as sustainable tourism, Integrated Coastal Zone Management and adaptation to Climate Change. In the last 5 years I built solid expertise on the issue of marine litter, in the fields of European policy development and implementation, societal awareness and stakeholder engagement. The report sustains my contribution to an improved position of European society in dealing with marine litter, in particular through a better integration of science in society and policies. This includes my participation in an expert group, contribution to 2 studies commissioned by the European Commission, contribution to the setup and implementation of the European projects MARLISCO and CleanSea. Between 2009 and 2016, I published 2 papers in peer-reviewed journals (including one as first author); was an oral speaker in 7 international conferences and co-author in 2 other oral presentations; had 3 summaries published in the Conference Proceedings; was co-author in 4 technical reports published by the European Joint Research Centre (including lead author in one of them); co-author in 2 studies commissioned by the European Commission; co-author in 2 brochures on marine litter for policy-makers.

2019-01-07Master thesis

Open access

Quercus suber – P. cinnamomi interaction: hypothetical molecular mechanism model

Publication . Coelho, A. C.; Horta, Marília; Ebadzad, G.; Cravador, A.

Phytophthora cinnamomi Rands is involved in the decline and mortality of Quercus suber L. and Quercus ilex L. in Southern Europe, in particular in Portugal and Spain. The presence and spread of P. cinnamomi in these regions is a severe threat to these oak ecosystems leading to expectable severe consequences for the production of cork and acorns in the near future. Molecular mechanisms underlying oomycete-host interactions are poorly understood. As a first step to identify transcripts involved in the Quercus suber – Phytophthora cinnamomi interaction, we applied complementary deoxyribonucleic acidamplified fragment length polymorphism (cDNA-AFLP) methodology to cork oak seedlings infected with zoospores or mycelium of P. cinnamomi. Forty-four Quercus suber genes that were differentially expressed when exposed to Phytophthora cinnamomi were selected and sequenced. Several of these genes were fully sequenced and the deduced aminoacid sequences showed consistent homology with proteins involved in the defence mechanism of other plant species. These findings led to the design of a simplified hypothetical model that illustrates the initial events of the interaction between Q. suber and P. cinnamomi.

2011Journal article

Open access