Progress towards Sustainable Control of Xylella fastidiosa subsp. pauca in Olive Groves of Salento (Apulia, Italy)

Xylella fastidiosa subsp. pauca is the causal agent of "olive quick decline syndrome" in Salento (Apulia, Italy). On April 2015, we started interdisciplinary studies to provide a sustainable control strategy for this pathogen that threatens the multi-millennial olive agroecosystem of Salento. Confocal laser scanning microscopy and fluorescence quantification showed that a zinc-copper-citric acid biocomplex-Dentamet®-reached the olive xylem tissue either after the spraying of the canopy or injection into the trunk, demonstrating its effective systemicity. The biocomplex showed in vitro bactericidal activity towards all X. fastidiosa subspecies. A mid-term evaluation of the control strategy performed in some olive groves of Salento indicated that this biocomplex significantly reduced both the symptoms and X. f. subsp. pauca cell concentration within the leaves of the local cultivars Ogliarola salentina and Cellina di Nardò. The treated trees started again to yield. A 1H-NMR metabolomic approach revealed, upon the treatments, a consistent increase in malic acid and γ-aminobutyrate for Ogliarola salentina and Cellina di Nardò trees, respectively. A novel endotherapy technique allowed injection of Dentamet® at low pressure directly into the vascular system of the tree and is currently under study for the promotion of resprouting in severely attacked trees. There are currently more than 700 ha of olive groves in Salento where this strategy is being applied to control X. f. subsp. pauca. These results collectively demonstrate an efficient, simple, low-cost, and environmentally sustainable strategy to control this pathogen in Salento

microbeMASST: A Taxonomically-informed Mass Spectrometry Search Tool for Microbial Metabolomics Data

microbeMASST, a taxonomically informed mass spectrometry (MS) search tool, tackles limited microbial metabolite annotation in untargeted metabolomics experiments. Leveraging a curated database of >60,000 microbial monocultures, users can search known and unknown MS/MS spectra and link them to their respective microbial producers via MS/MS fragmentation patterns. Identification of microbe-derived metabolites and relative producers without a priori knowledge will vastly enhance the understanding of microorganisms’ role in ecology and human health

A Taxonomically-informed Mass Spectrometry Search Tool for Microbial Metabolomics Data

MicrobeMASST, a taxonomically-informed mass spectrometry (MS) search tool, tackles limited microbial metabolite annotation in untargeted metabolomics experiments. Leveraging a curated database of >60,000 microbial monocultures, users can search known and unknown MS/MS spectra and link them to their respective microbial producers via MS/MS fragmentation patterns. Identification of microbial-derived metabolites and relative producers, without a priori knowledge, will vastly enhance the understanding of microorganisms’ role in ecology and human health

Epidemiological insights, cultivar resistance and natural products to control black dot (Colletotrichum coccodes) and silver scurf (Helminthosporium solani) on potato (Solanum tuberosum) tubers

Black dot and silver scurf are potato blemish diseases that reduce tuber quality. Although they had been considered of minor importance in the past, the commercialization of washed pre-packed potato tubers has led to an increase awareness of these diseases in the past 20 years. In this thesis, black dot and silver scurf are studied at the agronomic, cytologic and metabolomic levels. Field trials revealed the biotic and abiotic factors that affect the development of both diseases. Microscopy and metabolomics analysis of different potato cultivars exposed structural and biochemical factors of resistance to both diseases. Finally, a chemical characterization of plant extracts with potential as post-harvest control treatments was carried out. Overall, this thesis gives new insights in the epidemiology, host resistance and post-harvest control of black dot and silver scurf in potatoes, and control measures against both diseases are suggested to elaborate an integrated pest management

Biocontrol activity of three Pseudomonas in a newly assembled collection of Phytophthora infestans isolates

Late blight caused by the oomycete Phytophthora infestans constitutes the greatest threat to potato production worldwide. Considering the increasing concerns regarding the emergence of novel fungicide-resistant genotypes and the general demand for reducing inputs of synthetic and copper-based fungicides, the need for alternative control methods is acute. Several bacterial antagonists have shown anti-Phytophthora effects during in vitro and greenhouse experiments. We report the effects of three Pseudomonas strains recovered from field-grown potatoes against a collection of P. infestans isolates assembled for this study. The collection comprised 19 P. infestans isolates of mating types A1 and A2 greatly varying in fungicide resistance and virulence profiles as deduced from leaf disc experiments on Black’s differential set. The mycelial growth of all P. infestans isolates was fully inhibited when co-cultivated with the most active Pseudomonas strain (R47). Moreover, the isolates reacted differently to exposure to the less active Pseudomonas strains (S19 and R76). Leaf disc infection experiments with six selected P. infestans isolates showed that four of them, including highly virulent and fungicide-resistant ones, could be efficiently controlled by different potato-associated Pseudomonas strains

Insights on the Structural and Metabolic Resistance of Potato (Solanum tuberosum) Cultivars to Tuber Black Dot (Colletotrichum coccodes)

Black dot is a blemish disease of potato tubers caused by the phytopathogenic fungus Colletotrichum coccodes. Qualitative resistance (monogenic) that leads to the hypersensitive response has not been reported against black dot, but commercial potato cultivars show different susceptibility levels to the disease, indicating that quantitative resistance (polygenic) mechanisms against this pathogen exist. Cytological studies are essential to decipher pathogen colonization of the plant tissue, and untargeted metabolomics has been shown effective in highlighting resistance-related metabolites in quantitative resistance. In this study, we used five commercial potato cultivars with different susceptibility levels to black dot, and studied the structural and biochemical aspects that correlate with resistance to black dot using cytological and untargeted metabolomics methods. The cytological approach using semithin sections of potato tuber periderm revealed that C. coccodes colonizes the tuber periderm, but does not penetrate in cortical cells. Furthermore, skin thickness did not correlate with disease susceptibility, indicating that other factors influence quantitative resistance to black dot. Furthermore, suberin amounts did not correlate with black dot severity, and suberin composition was similar between the five potato cultivars studied. On the other hand, the untargeted metabolomics approach allowed highlighting biomarkers of infection, as well as constitutive and induced resistance-related metabolites. Hydroxycinnamic acids, hydroxycinnamic acid amides and steroidal saponins were found to be biomarkers of resistance under control conditions, while hydroxycoumarins were found to be specifically induced in the resistant cultivars. Notably, some of these biomarkers showed antifungal activity in vitro against C. coccodes. Altogether, our results show that quantitative resistance of potatoes to black dot involves structural and biochemical mechanisms, including the production of specialized metabolites with antifungal properties

Generation of Antifungal Stilbenes Using the Enzymatic Secretome of Botrytis cinerea

The protein secretome of Botrytis cinerea was used to perform the biotransformation of resveratrol, pterostilbene, and a mixture of both. Metabolite profiling by UHPLC-HRMS revealed the presence of compounds with unusual molecular formula, suggesting the existence of new products. To isolate these products, the reactions were scaled-up, and 21 analogues were isolated and fully characterized by NMR and HRESIMS analyses. The reaction with pterostilbene afforded five new compounds, while the reaction with a mixture of pterostilbene and resveratrol afforded seven unusual stilbene dimers. The antifungal properties of these compounds were evaluated using in vitro bioassays against Plasmopara viticola. The cytological effects of the isolated antifungal compounds on the ultrastructure of P. viticola were also evaluated

Emociones y educación : qué son y cómo intervenir desde la escuela

A raíz de las conclusiones del informe de la Comisión para la Educación del s.XXI (Informe Delors, 1996), se ha puesto de relieve la importancia de aprender a ser en relación con los demás. Este libro ofrece un mosaico de reflexiones y experiencias sobre la esfera de lo emocional realizadas en las aulas de infantil, primaria y secundaria. Dado que las emociones son básicas en la vida y en las relaciones, también deberían serlo en la educación..Ministerio Educación CIDEBiblioteca de Educación del Ministerio de Educación, Cultura y Deporte; Calle San Agustín 5 -3 Planta; 28014 Madrid; Tel. +34917748000; [email protected]