1,555 research outputs found

    Pectic enzymes as potential enhancers of ascorbic acid production through the D-galacturonate pathway in Solanaceae

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    The increase of L-Ascorbic Acid (AsA) content in tomato (Solanum lycopersicum) is a common goal in breeding programs due to its beneficial effect on human health. To shed light into the regulation of fruit AsA content, we exploited a Solanum pennellii introgression line (IL12-4-SL) harbouring one quantitative trait locus that increases the content of total AsA in the fruit. Biochemical and transcriptomic analyses were carried out in fruits of IL12-4-SL in comparison with the cultivated line M82 at different stages of ripening. AsA content was studied in relation with pectin methylesterase (PME) activity and the degree of pectin methylesterification (DME). Our results indicated that the increase of AsA content in IL12-4-SL fruits was related with pectin de-methylesterification/degradation. Specific PME, polygalacturonase (PG) and UDP-D-glucuronic-acid-4-epimerase (UGlcAE) isoforms were proposed as components of the D-galacturonate pathway leading to AsA biosynthesis. The relationship between AsA content and PME activity was also exploited in PMEI tobacco plants expressing a specific PME inhibitor (PMEI). Here we report that tobacco PMEI plants, altered in PME activity and degree of pectin methylesterification, showed a reduction in low methylesterified pectic domains and exhibited a reduced AsA content. Overall, our results provide novel biochemical and genetic traits for increasing antioxidant content by marker-assisted selection in the Solanaceae family

    Inhibition of inducible Nitric Oxide Synthase expression by an acetonic extract from Feijoa sellowiana Berg. fruits.

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    Feijoa sellowiana Berg. fruits and especially the acetonic extract have been shown to possess biological activities, although the responsible compounds have never been identified. The present study was designed to evaluate the anti-inflammatory activity of an acetonic extract from F. sellowiana Berg. fruits on the nitric oxide (NO) pathway, which plays an important role in inflammation. To this aim the J774 cell line, which expresses inducible nitric oxide synthase (iNOS) following stimulation with lipopolysaccharide (LPS), has been utilized, and the effects of this extract and its fractions on NO production, iNOS protein expression, and signal pathways involved in its regulation have been evaluated. This study demonstrates that at least some part of the anti-inflammatory activity of the acetonic extract is due to the suppression of NO production by flavone and stearic acid. The mechanism of this inhibition seems to be related to an action on the expression of the enzyme iNOS through the attenuation of nuclear factor κB (NF-κB) and/or mitogen-activated protein kinase (MAPK) activation

    Proposal for minimum information guidelines to report and reproduce results of particle tracking and motion analysis [preprint]

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    The proposed Minimum Information About Particle Tracking Experiments (MIAPTE) reporting guidelines described here aim to deliver a set of rules representing the minimal information required to report and support interpretation and assessment of data arising from intracellular multiple particle tracking (MPT) experiments. Examples of such experiments are those tracking viral particles as they move from the site of entry to the site of replication within an infected cell, or those following vesicular dynamics during secretion, endocytosis, or exocytosis. By promoting development of community standards, we hope that MIAPTE will contribute to making MPT data FAIR (Findable Accessible Interoperable and Reusable). Ultimately, the goal of MIAPTE is to promote and maximize data access, discovery, preservation, re-use, and repurposing through efficient annotation, and ultimately to enable reproducibility of particle tracking experiments. This document introduces MIAPTE v0.2, which updates the version that was posted to Fairsharing.org in October 2016. MIAPTE v0.2 is presented with the specific intent of soliciting comments from the particle tracking community with the purpose of extending and improving the model. The MIAPTE guidelines are intended for different categories of users: 1) Scientists with the desire to make new results available in a way that can be interpreted unequivocally by both humans and machines. For this class of users, MIAPTE provides data descriptors to define data entry terms and the analysis workflow in a unified manner. 2) Scientists wishing to evaluate, replicate and re-analyze results published by others. For this class of users MIAPTE provides descriptors that define the analysis procedures in a manner that facilitates its reproduction. 3) Developers who want to take advantage of the schema of MIAPTE to produce MIAPTE compatible tools. MIAPTE consists of a list of controlled vocabulary (CV) terms that describe elements and properties for the minimal description of particle tracking experiments, with a focus on viral and vesicular traffic within cells. As part of this submission we provide entity relationship (ER) diagrams that show the relationship between terms. Finally, we also provide documents containing the MIAPTE-compliant XML schema describing the data model used by Open Microscopy Environment inteGrated Analysis (OMEGA), our novel particle tracking data analysis and management tool, which is reported in a separate manuscript. MIAPTE is structured in two sub-sections: 1) Section 1 contains elements, attributes and data structures describing the results of particle tracking, namely: particles, links, trajectories and trajectory segments. 2) Section 2 contains elements that provide details about the algorithmic procedure utilized to produce and analyze trajectories as well as the results of trajectory analysis. In addition MIAPTE includes those OME-XML elements that are required to capture the acquisition parameters and the structure of images to be subjected to particle tracking

    Evidence for ground motion polarization on fault zones of mt. etna volcano

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    During local and regional earthquakes, an evident amplification of horizontal ground motion is observed at two seismological stations near the Tremestieri fault, on the southeastern flank of Mt. Etna volcano. Rotated-component spectral ratios show a narrow spectral peak around 4-Hz along a N40°E direction. A conventional polarization analysis using the eigenvectors of the covariance matrix confirms the very stable directional effect enhancing the approximately NE-SW elongation of the horizontal ground motion in the fault zone. The effect is evident during the entire seismogram and independent of source backazimuth as well as distance and depth of earthquakes. The same polarization is observed in ambient noise as well. This consistency allowed us to use microtremors for checking ground motion polarization along and across the Tremestieri fault zone with a high spatial resolution. The result is a stable polarization of horizontal motion in the entire area, interesting a broad frequency band. To check whether this ground motion property is recurrent and understand a possible relationship with fault strike, faulting style, or orientation of fractures, ambient noise was recorded on other mapped faults of the Mt. Etna area, the Moscarello, Acicatena and Pernicana faults. The latter, in particular, is characterized by different strike and faulting style. A systematic tendency of ambient noise to be polarized is found in all of the faults. A picture emerges where normal faults of the eastern flank show a E-W to NE-SW polarization that changes on the Pernicana fault, which develops approximately E-W and is characterized by a prevailing NW-SE to NS polarization. Directions of polarization were never parallel to the fault strike. Moreover, polarization persists too far away from the fault trace, excluding an effect limited to a narrow low velocity zone hosted between harder wall rocks. Both these observations rule out an interpretation in terms of fault-trapped waves. The cause of observed polarizations will be the subject of future studies. However, the consistency with recent results of velocity anisotropy in a part of the investigated area suggests a possible role of attenuation anisotropy on horizontal amplitude variations versus azimuth

    GC and GC-–MS Analysis of Volatile Compounds From Ballota nigra subsp. uncinata Collected in Aeolian Islands, Sicily (Southern Italy)

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    In the present study, the chemical composition of the essential oils from aerial parts of Ballota nigra subsp. uncinata (Beg.) Patzak collected in Sicily was evaluated by gas chromatography (GC) and GC-mass spectrometry. The main components of the oil were (E)-phytol (20.0%), alpha-pinene (9.0%), hexahydrofarnesyl acetone (5.7%), and alpha-selinene (5.1%). Cluster analysis of the essential oil compositions of all the taxa belonging to B. nigra s.l. group was performed

    Evidences for strong directional resonances in intensely deformed zones of the Pernicana fault, Mount Etna, Italy

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    In this paper we investigate ground motion properties in the western part of the Pernicana fault. This is the major fault of Mount Etna and drives the dynamic evolution of the area. In a previous work, Rigano et al. (2008) showed that a significant horizontal polarization characterizes ground motion in fault zones of Mount Etna, both during earthquakes and ambient vibrations. We have performed denser microtremor measurements in the NE rift segment and in intensely deformed zones of the Pernicana fault at Piano Pernicana. This study includes mapping of azimuth-dependent horizontal-to-vertical spectral ratios along and across the fault, frequency–wave number techniques applied to array data to investigate the nature of ambient vibrations, and polarization analysis through the conventional covariance matrix method. Our results indicate that microtremors are likely composed of volcanic tremor. Spectral ratios show strong directional resonances of horizontal components around 1 Hz when measurements enter the most damaged part of the fault zone. Their polarization directions show an abrupt change, by 20° to 40°, at close measurements between the northern and southern part of the fault zone. Recordings of local earthquakes at one site in the fault zone confirm the occurrence of polarization with the same angle found using volcanic tremor. We have also found that the directional effect is not time-dependent, at least at a seasonal scale. This observation and the similar behavior of volcanic tremors and earthquake-induced ground motions suggest that horizontal polarization is the effect of local fault properties. However, the 1-Hz resonant frequency cannot be reproduced using the 1-D vertically varying model inferred from the array data analysis, suggesting a role of lateral variations of the fault zone. Although the actual cause of polarization is unknown, a role of stress-induced anisotropy and microfracture orientation in the near-surface lavas of the Pernicana fault can be hypothesized consistently with the sharp rotation of the polarization angle within the damaged fault zone
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