First report of Hakea sericea leaf infection caused by Pestalotiopsis funerea in Portugal

[Excerpt] The woody shrub Hakea sericea (Proteaceae) is native of south-eastern Australia and has been considered as an invader of natural habitats. In northern Portugal, dense stands of this plant are rapidly spreading usually after intense forest fires (Fig. 1a). In May 2003, unusual leaf spots were observed on these naturally growing plants. Infected plants exhibit reddish leaves bearing black circular lesions with 1-3 mm in diameter (Fig. 1b,c). Leaf sections containing necrotic lesions were plated onto PDA (potato dextrose agar) and eight fungi isolates were obtained. Pure cultures exhibit pinkish mycelium bearing compact acervuli containing black and slimy spore masses (Fig. 2a). Microscopic observation revealed typical Pestalotiopsis sp. 5-celled spores (3 coloured median and 2 hyaline end cells) with 3-4 apical and 1 basal appendages (Fig. 2b,c). The identification of Pestalotiopsis at species level is difficult and has been based on morphological characteristics of conidia (Guba, 1961). Recently, molecular approaches have been reported based on sequencing the internal transcribed spacer region (ITS) of the ribosomal RNA operon and comparision of the sequenced region to its orthologs of already identified Pestalotiopsis species (Jeewon et al., 2002). In this work, genomic DNA from fungi isolates was purified using DNeasy ® Plant Mini Kit (Qiagen), and used as template in thermocyclic amplifications using Ready-To-GoTM PCR Beads (Amersham Biosciences) with ITS5 and ITS4 universal primers (White et al., 1990). The amplified sequences (599bp) were then analysed together with other Pestalotiopsis ITS sequences already edited in databases, using the programs ClustalX (alignment of sequences), GeneDoc (manual correction of the alignment) and Phylip (phylogenetic tree construction). The results showed that ITS sequences from all fungi isolates were identical to each other and 99.3% similar to Pestalotiopsis funerea (Fig. 3). To confirm the pathogenecity of Pestalotiopsis funerea towards Hakea sericea, 6 weeks-old plants grown in vitro were infected with a suspension containing 105 spores/ml and maintained at 22°C, under 16 h lightphotoperiod. After 6 days, in vitro plants exhibited tissue lesions identical to those observed in field plants, bearing fungus spores identical to those from original isolates. [...]Fundação para a Ciência e a Tecnologia (FCT) - grant ref. SFRH/BD/10899/2002

Transformer-based language models for semantic search and mobile applications retrieval

Search engines are being extensively used by Mobile App Stores, where millions of users world-wide use them every day. However, some stores still resort to simple lexical-based search engines, despite the recent advances in Machine Learning, Information Retrieval, and Natural Language Processing, which allow for richer semantic strategies. This work proposes an approach for semantic search of mobile applications that relies on transformer-based language models, fine-tuned with the existing textual information about known mobile applications. Our approach relies solely on the application name and on the unstructured textual information contained in its description. A dataset of about 500 thousand mobile apps was extended in the scope of this work with a test set, and all the available textual data was used to fine-tune our neural language models. We have evaluated our models using a public dataset that includes information about 43 thousand applications, and 56 manually annotated non- exact queries. The results show that our model surpasses the performance of all the other retrieval strategies reported in the literature. Tests with users have confirmed the performance of our semantic search approach, when compared with an existing deployed solution.info:eu-repo/semantics/acceptedVersio

Hakea sericea Schrad. - a model to study phosphate uptake in proteoid roots

Comunicação em painel apresentada no XIV Congresso Nacional de Bioquímica, 2 a 4 Dezembro 2004, Vilamoura.P is an important macronutrient, making up about 0.2% of a plant dry weight. Pi is the form of P most readily accessed by plants, the concentration of which rarely exceeds 10 µM in soil. Here we studied the mechanisms involved on Pi uptake from soil in Hakea sericea Schrad. (Proteacea), an Australian invader of natural habitats, able to develop proteoid roots as a response to P deficiency. H. sericea proteoid roots have efficient transporters for extraction of Pi from soil. Uptake studies supported the involvement of two Pi transport systems with the following kinetic parameters: for the high-affinity system Km, 6 µM Pi and Vmax, 5 µmolh-1g-1 FW; for the low-affinity system Km, 100 µM Pi and Vmax, 24 µmolh-1g-1 FW. The protonophore CCCP (50 µM) inhibited up to 60% the initial uptake rates of 5-50 µM Pi (high-affinity range) and 100-500 µM (low-affinity range), suggesting H+-dependent transport. Both transporters were competitively inhibited by phosphite and 100 µM mersalyl reduced by 50% the initial uptake rates of 10 µM Pi. PCR using degenerate primers designed for the conserved regions of Pi transporter genes from higher plants allowed the amplification of two 437 bp fragments sharing 77,4% identity with each other. Both nucleotide sequences comprise an incomplete ORF coding for transmembrane domains and exhibit homology with other plant Pi transporters. These nucleotide sequences are being used as probes in the identification of complete sequences of Pi transporter genes in H. sericea genome.Fundação para a Ciência e a Tecnologia (FCT) - grant ref. SFRH/BD/10899/2002 , grant ref. SFRH/BD/13460/2003

Orthophosphate uptake in proteoid roots of naturally occurring Hakea sericea Schrad.

Poster apresentado no congresso "14th Congress of the Federation of European Societies of Plant Biology", August 23-27, 2004, Cracow, Poland.P is an important macronutrient, making up about 0.2% of a plant’s dry weight. The form of P most readily accessed by plants is Pi, the concentration of which rarely exceeds 10 µM in soil (Schachtman et al., 1998). Here we studied the mechanisms involved on extraction of Pi from soil in Hakea sericea Schrad. (Proteacea), an Australian invader of natural habitats, which is able to develop proteoid roots as a response to P deficiency. Material and Methods: Proteoid roots were harvested from adult H. sericea shrubs growing in Serra d’Arga, Northern Portugal. The P uptake buffer contained 2.5-4000 µM NaH2PO4 and Pi concentration was determined according to Adams (1991). PCR amplification was performed using genomic DNA and degenerate primers based on the most conserved regions of plant P transporters genes. Results and Conclusions: H. sericea proteoid roots have highly efficient transporters for extraction of Pi from soil. Kinetic studies supported the involvement of two Pi mediated transport systems associated with a diffusion-like mechanism. The kinetic parameters were as follows: for the high-affinity system Km, 11 µM Pi and Vmax, 7 µmol h-1 g-1 FW; for the low-affinity system Km, 163 µM Pi and Vmax, 30 µmol h-1 g-1 FW. The protonophore CCCP (50 µM) inhibited up to 60% the initial uptake rates of 5-50 µM Pi (high-affinity range) and 100-500 µM (low-affinity range), suggesting H+-dependent transport. Both transporters were competitively inhibited by phosphite and 100 µM mersalyl reduced by 50% the initial uptake rates of 10 µM Pi. PCR using degenerate primers allowed the amplification of two 438 bp fragments sharing 87.4% identity with each other. Both nucleotide sequences comprise an incomplete ORF coding for transmembrane domains and exhibiting 85-82% identity with other plant P transporters. These nucleotide sequences are being used for the identification of complete cDNAs of Pi transporter genes of H. sericea.Fundação para a Ciência e a Tecnologia (FCT) - Bolsa Ref. SFRH/BD/10899/2002 , Bolsa Ref. SFRH/BD/13460/2003

A new method for testing antimicrobial activity of filamentous fungi

Tbls work was supporled by a FCT projecl (PTDC/AGR-AAM/099556/2008)

Identification of Zantedeschia aethiopica Cat1 and Cat2 catalase genes and their expression analysis during spathe senescence and regreening

Plants encode catalase (CAT; EC 1.11.1.6) as multigene families, which may reflect the multiple and diverse roles played by this enzyme. Catalases from higher plants can be subdivided into three distinct types, according to their phylogenetic relationship. However, there is not a specific correlation of phylogeny and function within these groups, as catalases from the same type can play different specific roles. We report on the characterization of two monocot catalase genes from Zantedeschia aethiopica (a C_3-type Araceae) and its expression analysis during spathe senescence and regreening. Z. aethiopica CAT2 appears to play an exclusive role in scavenging photorespiratory H_2O_2, but is more phylogenetically related to the unspecific Zea mays CAT3 and Oryza sativa CATA than to the photorespiratory-related Zea mays CAT2 and Oryza sativa CATC. Z. aethiopica CAT1 is more phylogenetically related to Zea mays CAT1 and Oryza sativa CATB and appears to have a dual role in scavenging glyoxysomal and peroxisomal H_2O_2.Fundação para a Ciência e a Tecnologia (FCT) - PRAXIS XXI/BD/16280/98 , SFRH/BD/12081/2003

Estudo do aproveitamento de quatro resíduos agroindustriais para produção de carvão vegetal.

Resumo. Disponível online. MIPE

Influence of hypholoma fasciculare in portuguese chestnut groves sustainability

The chestnut tree (Castanea sativa) has an enormous economic importance at national level, mainly due to the value of the fruit (chestnut) and the high quality of the wood. The presence of the fungus Hypholoma fasciculare has been observed in chestnut orchard soils of Trás-os-Montes (Portugal). Although it is described as being a saprophyte, preliminary studies have demonstrated that H. fasciculare could cause serious damage to the chestnut trees. On the other hand, it has an expressive antagonist action against other soil-borne fungi present in chestnut groves. In order to assess the consequences arising from the presence of this fungus on soil microbial diversity, the effect of the presence of H. fasciculare was evaluated. In this way, the fungal community of soils from three chestnut groves presenting different levels of H. fasciculare was compared. After DNA extraction from 10 soil cores from each soil, the ITS regions were amplified using the adequate primers for fungal sequences and 454 pyrosequencing was used for the assessment of soil metagenomes. Results will be presented taking into account the diversity of fungal trophic groups that could be important for chestnut sustainability, mainly the ectomycorrhizal fungi. These results will contribute to the identification of soil microbial species most affected by the presence of H. fasciculare, making it possible to assess the action of this fungus on beneficial mycorrhizal fungi to the chestnut tree.This work is supported by Fundação para a Ciência e a Tecnologia (FCT) I&D grant PTDC/ AGR-AAM/099556/200

Predictive Factors of Relapse After Methotrexate Discontinuation in Juvenile Idiopathic Arthritis Patients With Inactive Disease

Objective: To identify predictive factors of relapse after discontinuation of Methotrexate (MTX) in Juvenile Idiopathic Arthritis (JIA) patients with inactive disease. Methods: We conducted a prospective multicenter cohort study of patients diagnosed with JIA using real world data from the Portuguese national register database, Reuma.pt. Patients with JIA who have reached JADAS27 inactive disease and discontinued MTX before the age of 18 were evaluated. Results: A total of 1470 patients with JIA were registered in Reuma.pt. Of the 119 bionaive patients who discontinued MTX due to inactive disease, 32.8% have relapsed. Median time of persistence (using the Kaplan-Meier method and log-rank tests) with inactive disease was significantly higher in patients with more than two years of remission before MTX discontinuation and in those who did not use NSAIDs at time of MTX discontinuation. In Cox regression analyses and after adjustment for age at diagnosis, MTX tapering and JIA category, the use of NSAIDs at the time of MTX discontinuation (HR, 1.98 95%CI 1.03-3.82) and remission time of less than two years before suspension (HR, 3.12 95%CI 1.35-7.13) remained associated with relapse. No association was found between JIA category or the regimen of MTX discontinuation and the risk of relapse. Conclusions: In this large cohort we found that the use of NSAIDs at the time of MTX discontinuation was associated with a two times higher likelihood of relapse. In addition, longer duration of remission before MTX withdrawal reduces the chance of relapse in bionaive JIA patients.info:eu-repo/semantics/publishedVersio