1,721,074 research outputs found
The tomato serotonin pathway: unravelling the puzzling biological roles of plant indolamines
Full text linkTryptamine and serotonin are specialized metabolites belonging to the group of tryptophan-derived indolamines that have been demonstrated to be widespread among all the living kingdoms, in which evolution shaped very different distributions and functional versatility. First discovered in humans, these metabolites were later detected in plants in which, despite their wide occurrence in several plant families, the study of their biological roles has been largely neglected. Tryptamine, due to its central position as a precursor of many plant specialized metabolites, including serotonin, has long been considered a mere metabolic intermediate; on the other hand, the increasing awareness of the many medical issues of serotonin (e.g. neurotransmission and hormonal activity), triggered the botanical research towards the elucidation of its biosynthetic pathway and functions also in plants, leading to a huge number of experimental evidences that, yet often controversial, suggest its putative involvement in many different plant physiological processes (e.g. development, stress response and reproduction). This PhD thesis proposed to shed a light on the biological roles of plant tryptamine and serotonin, with a particular focus on an aspect that has never been investigated in plants, i.e. the high level of accumulation of these metabolites within the reproductive organs, such as the fruit, observed in many edible species, which, given the high costs to plant metabolism, can be reasonably hypothesized to reflect an important plant physiological function. To fulfil this aim, this PhD project relied on the use of Solanum lycopersicum, a tryptamine and serotonin accumulator that is a model plant for fruit-bearing crops. The first step consisted in the genetic characterization of the tomato tryptamine and serotonin biosynthetic pathway: a three-member gene family and one single gene codifying for the enzymes of the 2-step pathway that leads to the production of serotonin from tryptophan via tryptamine (i.e. tryptophan decarboxylase, TDC and tryptamine-5-hydroxylase, T5H) were respectively identified and functionally characterized as bona-fide SlTDCs and SlT5H. The expression analysis of these genes and the investigation of tryptamine and serotonin distribution revealed organ and developmental-specific expression and accumulation patterns in tomato, confirming the complementary but not redundant activity of the three SlTDC genes in the plant and the presence of notable amounts of the two indolamines in the fruit, which accumulated with a characteristic trend during development and ripening. Moreover, it was revealed the fruit-specific nature of the SlTDC1 gene that, as a preliminary point in the elucidation of the biological roles of plant tryptamine and serotonin, was targeted by a metabolic engineering approach in order to look for the effects resulting from altered levels of these metabolites on the plant phenotype. Transgenic plants overexpressing this gene resulted in deep modifications of plant metabolome presenting in one case altered morphology of younger leaves. This evidence, together with the observation along the main axis of the wild type plant of complex expression and accumulation gradients of SlTDCs/SlT5H genes and related products, i.e. tryptamine and serotonin, leads to hypothesize the possible interference with the hormonal cross-talk. On the other hand, SlTDC1 knock-out fruits did non exhibit obvious phenotype but further characterization of their metabolome are needed to speculate on the biological roles of tryptamine and serotonin in this organ. In summary, this work provided useful information and details to the biosynthesis, regulation and putative biological roles of plant indolamines in the model plant of tomato and highlighted the putative involvement of the actors of the plant serotonin pathway in important physiological functions, which deserve, thus, future deeper investigation
Il progetto dell’illusione. La nascita del Teatro Regio nei disegni inediti di Nicolò Bettoli
No full textUna nutrita serie inedita di disegni architettonici e di testi a opera dell’architetto neoclassico Nicolò Bettoli (Parma, 1780-1854) consente di ricostruire la pressoché ignota genesi progettuale del maggior teatro parmense, lungo un percorso cronologico e tematico restituito dall’esposizione curata dagli stessi autori per il Comune di Parma presso la Pinacoteca Stuard, che recentemente ha ottenuto in donazione il fondo bettoliano
The Potential Role of Exercise Training and Mechanical Loading on Bone-Associated Skeletal Nerves
Full text link: The spatial distribution, innervation, and functional role of the bone-associated skeletal nerves have been previously reported in detail. However, studies examining exercise-induced associations between skeletal nerves and bone metabolism are limited. This review introduces a potential relationship between exercise and the skeletal nerves and discusses how it can contribute to exercise-induced bone anabolism. First, the background and current understanding of nerve fiber types and their functions in the skeleton are provided. Next, the influence of exercise and mechanical loading on the skeletal nervous system is elaborated. Effective synthesis of recent studies could serve as an established baseline for the novel discovery of the effects of exercise on skeletal nerve density and bone anabolic activity in the future. Therefore, this review overviews the existing evidence for the neural control of bone metabolism and the potential positive effects of exercise on the peripheral skeletal nervous system. The influence of exercise training models on the relationships of sensory nerve signals with osteoblast-mediated bone formation and the increased bone volume provides the first insight on the potential importance of exercise training in stimulating positive adaptations in the skeletal nerve-bone interaction and its downstream effect on bone metabolism, thereby highlighting its therapeutic potential in a variety of clinical populations
Temperature and solar irradiation effects on secondary metabolism during ripening of field-grown everbearing strawberries
No full textThe garden strawberry (Fragaria x ananassa Duch.) is cultivated and consumed worldwide because of the pleasant flavor and health-promoting phytochemicals of its false fruits. Monocrop cultivars produce fully ripe strawberries in about one month post-anthesis throughout the spring, while everbearing cultivars undergo additional strawberry production in autumn. In this work, we evaluated the impact of different season-dependent environmental conditions on the ripening program of an everbearing field-gown strawberry variety from autumn 2015 to spring 2016. We combined ad hoc sampling and environmental data collection with LC-MS-based untargeted metabolomics to dissect the effects of cumulative temperature and solar irradiation on fruit quality parameters and secondary metabolism during ripening. Different dynamics in specific sub-groups of metabolites were observed in strawberries experiencing distinct amounts of cumulative temperature and solar irradiation during spring and autumn. The integration of statistical analyses on collected data revealed that solar irradiation mainly affected fruit fresh weight and organic acid levels, whereas temperature had a more selective effect on the accumulation of specific flavonols, anthocyanins, and soluble sugar. These findings are of suitable interest to design further approaches for the study of the complex interactions among environmental conditions and ripening in strawberries grown in a real-world scenario
P.D.O. Percutaneous Distal Osteotomy
No full textSurgical treatment of mild to moderate hallux valgus can be performed by a minimally invasive surgical percutaneous approach with a distal osteotomy of the first metatarsal. The osteotomy is fixed by means of a single Kirschner wire
Diagnosis and Conservative Treatment of Adolescent Idiopathic Scoliosis: Case Presentation
No full text12 years old female referred for scoliosis by a family pediatrician. She is 2 months postmenarchal and has no medical problems. She is engaged in typical activities for an adolescent female including volleyball and dance. Past medical history (PMH) and past surgical history (PSH) unremarkable
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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