Enhancing immunity by engineering DAMPs

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GRP-3 and KAPP, encoding interactors of WAK1, negatively affect defense responses induced by oligogalacturonides and local response to wounding

Conserved microbe-associated molecular patterns (MAMPs) and damage-associated molecular patterns (DAMPs) act as danger signals to activate the plant immune response. These molecules are recognized by surface receptors that are referred to as pattern recognition receptors. Oligogalacturonides (OGs), DAMPs released from the plant cell wall homogalacturonan, have also been proposed to act as local signals in the response to wounding. The Arabidopsis Wall-Associated Kinase 1 (WAK1), a receptor of OGs, has been described to form a complex with a cytoplasmic plasma membrane-localized kinase-associated protein phosphatase (KAPP) and a glycine-rich protein (GRP-3) that we find localized mainly in the cell wall and, in a small part, on the plasma membrane. By using Arabidopsis plants overexpressing WAK1, and both grp-3 and kapp null insertional mutant and overexpressing plants, we demonstrate a positive function of WAK1 and a negative function of GRP-3 and KAPP in the OG-triggered expression of defence genes and the production of an oxidative burst. The three proteins also affect the local response to wounding and the basal resistance against the necrotrophic pathogen Botrytis cinerea. GRP-3 and KAPP are likely to function in the phasing out of the plant immune response

Loss of the arabidopsis protein kinases ANPs affects root cell wall composition, and triggers the cell wall damage syndrome

The Arabidopsis NPK1-related Protein kinases ANP1, ANP2 and ANP3 belong to the MAP kinase kinase kinase (MAPKKK) superfamily and were previously described to be crucial for cytokinesis, elicitor-induced immunity and development. Here we investigate the basis of their role in development by using conditional β-estradiol-inducible triple mutants to overcome lethality. In seedlings, lack of ANPs causes root cell bulging, with the transition zone being the most sensitive region. We uncover a role of ANPs in the regulation of cell wall composition and suggest that developmental defects of the triple mutants, observed at the cellular level, might be a consequence of the alterations of the pectic and cellulosic cell wall components. Lack of ANPs also induced a typical cell wall damage syndrome (CWDS) similar to that observed in plants treated with the cellulose biosynthesis inhibitor isoxaben (ISX). Moreover, anp double mutants and plants overexpressing single ANPs (ANP1 or ANP3) respectively showed increased and reduced accumulation of jasmonic acid and PDF1.2 transcripts upon ISX treatment, suggesting that ANPs are part of the pathway targeted by this inhibitor and play a role in cell wall integrity surveillance

Dampening the DAMPs: how plants maintain the homeostasis of cell wall molecular patterns and avoid hyper-immunity

Several oligosaccharide fragments derived from plant cell walls activate plant immunity and behave as typical damage-associated molecular patterns (DAMPs). Some of them also behave as negative regulators of growth and development, and due to their antithetic effect on immunity and growth, their concentrations, activity, time of formation, and localization is critical for the so-called “growth-defense trade-off.” Moreover, like in animals, over accumulation of DAMPs in plants provokes deleterious physiological effects and may cause hyper-immunity if the cellular mechanisms controlling their homeostasis fail. Recently, a mechanism has been discovered that controls the activity of two well-known plant DAMPs, oligogalacturonides (OGs), released upon hydrolysis of homogalacturonan (HG), and cellodextrins (CDs), products of cellulose breakdown. The potential homeostatic mechanism involves specific oxidases belonging to the family of berberine bridge enzyme-like (BBE-like) proteins. Oxidation of OGs and CDs not only inactivates their DAMP activity, but also makes them a significantly less desirable food source for microbial pathogens. The evidence that oxidation and inactivation of OGs and CDs may be a general strategy of plants for controlling the homeostasis of DAMPs is discussed. The possibility exists of discovering additional oxidative and/or inactivating enzymes targeting other DAMP molecules both in the plant and in animal kingdoms

Is this sentence difficult? Do you agree?

In this paper, we present a crowdsourcing-based approach to model the human perception of sentence complexity. We collect a large corpus of sentences rated with judgments of complexity for two typologically-different languages, Italian and English. We test our approach in two experimental scenarios aimed to investigate the contribution of a wide set of lexical, morpho-syntactic and syntactic phenomena in predicting i) the degree of agreement among annotators independently from the assigned judgment and ii) the perception of sentence complexity

Gliding Arc Reactor under AC Pulsed Mode Operation:Spatial Performance Profile for NO_x Synthesis

A two-dimensional gliding arc reactor for NOx synthesis was investigated in this study using AC pulsed mode operation. Tests with a duty cycle of 40 or 60% achieved the lowest energy consumption of 6.95 MJ/mol, which is an improvement of 15% from the case of continuous operation. Based on the results achieved, a new method for analyzing the spatial profile of the reactor was presented. The reactor was divided into five zones along the arc propagation, and results indicated that the first zone and last zone of the gliding arc reactor had higher energy consumption (9.59 and 8.63 MJ/mol, respectively), while lower consumption was observed in the middle parts of the reactor with a minimum of 5.00 MJ/mol. Spatial-resolved optical emission spectra, the deduced electron density, and temperature indicated the nonuniformity in plasma properties, which corresponds to the NOx production performance across the reactor. This research provides information and discussion that can be used for understanding and optimization of gliding arc reactors toward efficient nitrogen fixation.</p

Plasma assisted non-oxidative methane coupling over Ni-Fe mixed metal oxides

In this work, Ni-Fe mixed metal oxides with different Fe/Ni molar ratios of 0.33, 1 and 3 were synthesized by hydrothermal method at a constant pH. The obtained catalysts were characterized via XRD, TEM, ICP-OES, XPS and nitrogen physisorption. The catalysts were tested at room temperature for plasma-assisted non-oxidative coupling of methane with a mixture of 20 vol% CH4 in Ar in a planar DBD reactor with an electrode gap of 1.5 mm. The Fe3Ni showed the highest methane conversion of 7.4% with a 26% selectivity towards ethylene and an energy consumption as low as 0.55 MJ·molC2H4-1. The XPS spectra of Fe3Ni showed a surface enrichment in Ni3+ and Fe2+ promoting ethylene desorption rate as compared with the other two synthesized catalysts. The CH4 conversion increases up to 5 times with decreasing the CH4/Ar molar ratio in the feed at constant flow rate of 100 ml∙min-1. All the catalysts showed a similar relative decrease of conversion and increase of energy consumption. Negligible carbon deposition rate was observed and the total selectivity to C2 and C3 hydrocarbons was close to 100%, indicating the advantages of the catalytic formulation proposed for methane activation in plasma environment.</p

Italian in the Trenches: Linguistic Annotation and Analysis of Texts of the Great War

The paper illustrates the design and development of a textual corpus representative of the historical variants of Italian during the Great War, which was enriched with linguistic (lemmatization and pos-tagging) and meta-linguistic annotation. The corpus, after a manual revision of the linguistic annotation, was used for specializing existing NLP tools to process historical texts with promising results.L’articolo illustra la progettazione e la costruzione di un corpus rappresentativo delle varietà di italiano in uso durante la prima Guerra Mondiale, annotato con dati linguistici (lemmatizzazione, analisi morfo-sintattica) e meta-linguistici. Il corpus, a seguito della revisione manuale dell’annotazione linguistica, è stato utilizzato per l’adattamento degli strumenti NLP esistenti, con risultati promettenti

Voices of the great war: A richly annotated corpus of Italian texts on the first world war

Voci della Grande Guerra (“Voices of the Great War”) is the first large corpus of Italian historical texts dating back to the period ofFirst World War. This corpus differs from other existing resources in several respects. First, from the linguistic point of view it givesaccount of the wide range of varieties in which Italian was articulated in that period, namely from a diastratic (educated vs. uneducatedwriters), diaphasic (low/informal vs. high/formal registers) and diatopic (regional varieties, dialects) points of view. From the historicalperspective, through a collection of texts belonging to different genres it represents different views on the war and the various styles ofnarrating war events and experiences. The final corpus is balanced along various dimensions, corresponding to the textual genre, thelanguage variety used, the author type and the typology of conveyed contents. The corpus is annotated with lemmas, part-of-speech,terminology, and named entities. Significant corpus samples representative of the different “voices” have also been enriched withmeta-linguistic and syntactic information. The layer of syntactic annotation forms the first nucleus of an Italian historical treebankcomplying with the Universal Dependencies standard. The paper illustrates the final resource, the methodology and tools used to buildit, and the Web Interface for navigating it