Search

The spread of the invasive and allergenic Ambrosia artemisiifolia L. in Italy was analysed and mapped using distribution data from a wide range of sources. Ambrosia artemisiifolia occupies 1057 floristic quadrants which are mostly distributed in the Po plain. The distribution obtained represents the basis to implement urgent management strategies.

Investigations of the genetic pattern and colonisation sources and the routes of invasion by alien species populations are crucial for identifying invasion mechanisms and the reasons for the bio-ecological success of invasive species. The aim of our work was to study the genetic pattern of Italian populations of Ambrosia artemisiifolia in comparison with that of some French and Canadian populations and to use herbarium records to characterise the colonisation areas of A. artemisiifolia across Italy. Molecular investigations were based on a set of nuclear SSR marker loci, which we used to analyse a number of Italian, Canadian and France populations. The time-spatial spread of A. artemisiifolia was reconstructed through the distributional pathway of 194 herbarium specimens.Ambrosia artemisiifolia Italian populations (HE = 0.687) had higher values of genetic diversity when compared to Canadian (HE = 0.639) and French (HE = 0.643) populations. Nevertheless, the time of residence of the Italian populations was positively correlated with the observed and expected heterozygosity (HO, HE). Genetic clustering inferred in STRUCTURE suggested admixture of populations with different ancestry. Historical distributional data highlighted that A. artemisiifolia first colonised the Po plain and different phased localities of the Mediterranean region. This study synthesises genetic and historical distributional data, highlighting that several invasion events have occurred across the Italian peninsula in different spatio-temporal steps, establishing high levels of historic gene flow between populations with mixed ancestry.

Pollen allergenicity is one of the main factors influencing the prevalence and/or severity of allergic diseases. However, how genotype and environment contribute to ragweed pollen allergenicity has still to be established. To throw some light on the factors governing allergenicity, in this work 180 ragweed plants from three Regions (Canada, France, Italy) were grown in both controlled (constant) and standard environmental conditions (seasonal changes in temperature, relative humidity and light). Pollen from single plants was characterized for its allergenic potency and for the underlying regulation mechanisms by studying the qualitative and quantitative variations of the main isoforms of the major ragweed allergen Amb a 1. Results showed a statistically higher variability in allergenicity of pollen from standard conditions than from controlled conditions growing plants. This variability was due to differences among single plants, regardless of their origin, and was not ascribed to differences in the expression and IgE reactivity of individual Amb a 1 isoforms but rather to quantitative differences involving all the studied isoforms. It suggests that the allergenic potency of ragweed pollen and thus the severity of ragweed pollinosis mainly depends on environmental conditions during plant growth and flowering, which regulate the total Amb a 1 content.

Melting (MF) and non melting flesh (NMF) peaches differ in their final texture and firmness. Their specific characteristics are achieved by softening process and directly dictate fruit shelf life and quality. Softening is influenced by various mechanisms including cell wall reorganization and water loss. In this work, the biomechanical properties of MF Spring Crest's and NMF Oro A's exocarp and mesocarp along with the amount and localization of hydroxycinnamic acids and flavonoids were investigated during fruit ripening and post-harvest. The objective was to better understand the role played by water loss and cell wall reorganization in peach softening. Results showed that in ripe Spring Crest, where both cell turgor loss and cell wall dismantling occurred, mesocarp had a little role in the fruit reaction to compression and probe penetration response was almost exclusively ascribed to the epidermis which functioned as a mechanical support to the pulp. In ripe Oro A's fruit, where cell wall disassembly did not occur and the loss of cell turgor was observed only in mesocarp, the contribution of exocarp to fruit firmness was consistent but relatively lower than that of mesocarp, suggesting that in addition to cell turgor, the integrity of cell wall played a key role in maintaining NMF fruit firmness. The analysis of phenols suggested that permeability and firmness of epidermis were associated with the presence of flavonoids and hydroxycinnamic acids.

The invasion of Ambrosia artemisiifolia across European countries has been favoured by its ecological amplitude and by its ability to colonise and dominate disturbed/ruderal areas that have lost competition from native species. We supposed that a strong competition for habitat resources may inhibit A. artemisiifolia growth, generating a negative feedback to its establishment. Based on this hypothesis, in this study, we undertook a 1-year field experiment to assess the effect of mixtures of grassland species on A. artemisiifolia growth and fitness in bare soils. We applied three different treatments within an abandoned quarry area invaded by A. artemisiifolia: (i) spontaneous succession, (ii) hayseed and (iii) a commercial seed mixture. Within plots, we recorded vegetation parameters, A. artemisiifolia abundance and traits. Results obtained after one growing season showed that the commercial seed resulted in the strongest reduction of A. artemisiifolia growth rate in terms of plant height, lateral spread and leaf size. This was ascribed to higher density of plants that play a key role in reducing biomass and fitness of A. artemisiifolia. However, hayseed should be preferred, as it preserves local biodiversity. Seeding mixtures of grassland species can successfully suppress A. artemisiifolia in the first year of establishment on a vegetation-free soil derived from quarry activities. This study indicated that inducing dominance of different native species in a newly developing plant community should enhance competition for resources, reducing the success of early coloniser non-native species.

During interglacial stages, microrefugia are sites that support locally favorable climates within larger areas with unfavorable warmer climates. Despite recent theoretical representations of microrefugia, an appropriate ecological characterization is still lacking, mostly for warm periods. Across mountain/alpine areas, cold-adapted plant species could adopt different strategies to manage the effects of climate warming: (A) migration toward higher elevations and summits; (B) in situ resilience of communities and species populations within microrefugia; and C) adaptation and evolution by genetic differentiation. This review aims to distinguish and characterize from an ecological perspective glacial, nival, periglacial and composite landforms and deposits that may function as potential microrefugia during interglacial warm periods.We conducted a literature screening related to the geomorphological processes and landforms associated with vegetation and plant communities in alpine/mountain environments of Europe. They include glacial deposits rock glaciers, debris-covered glaciers, composite cones and channels. In Alpine regions, geomorphologic niches that constantly maintain cold-air pooling and temperature inversions are the main candidates for microrefugia. Within such microrefugia, microhabitat diversity modulates the responses of plants to disturbances caused by geomorphologic processes and supports their aptitude for surviving under extreme conditions on unstable surfaces in isolated patches. Currently, European marginal mountain chains may be considered as examples of macrorefugia where relict boreo-alpine species persist within peculiar geomorphological niches that act as microrefugia.This review contributes to identifying potential warm-stage microrefugia areas across alpine and mountain regions and determining certain landforms that play or may play such role under global-change scenarios. The occurrence of warm-stage microrefugia within these locations may be

Background: In many areas of Europe, double sensitization to ragweed and mugwort is common, and because of the overlapping flowering periods of the 2 plants, it is not possible to diagnose the primary sensitizing allergen source and hence to determine the proper immunotherapy. Objectives: To elucidate whether double-sensitized patients are cosensitized or cross-sensitized and, in the latter case, to define the primary sensitizer. Methods: Serum samples from 34 patients with late summer respiratory allergy underwent skin prick testing with whole ragweed, and mugwort extracts were analyzed for their reactivity to recombinant Art v 1 and Amb a 1 by ImmunoCAP and then to Amb a 1, Art v 6, and Art v 1 isoforms by a proteomic approach. In double reactors, the primary sensitizing sources were detected by inhibition experiments. Results: Serum samples from patients monosensitized to ragweed contained IgE to epitopes specific of all Amb a 1 isoforms. In contrast, serum samples from double reactors found to be primarily sensitized to mugwort reacted to Art v 1 and Art v 6 and cross-reacted to a few Amb a 1 isoforms. Finally, serum samples from double reactors found to be primarily sensitized to ragweed contained IgE reacting to all Amb a 1 isoforms, part of which cross-reacted to Art v 6. We did not find cosensitized patients. Conclusion: This study found that Art v 6 plays an important role in mugwort allergy and that the cross- reactivity between Art v 6 and Amb a 1 is frequent, bidirectional, and clinically relevant in the area of Milan.

This study was undertaken to investigate combined toxic and genotoxic effects of cadmium (Cd) and arsenic (As) on white clover, a pollutant sensitive plant frequently used as environmental bioindicator. Plants were exposed to soil spiked with increasing concentrations of cadmium sulfate (20, 40 and 60 mg Kg 21 ) or sodium arsenite (5, 10 and 20 mg Kg 21 ) as well as with their combinations. Metal(loid) bioavailability was assessed after soil contamination, whereas plant growth, metal(loid) concentration in plant organs and DNA damage were measured at the end of plant exposition. Results showed that individual and joint toxicity and genotoxicity were related to the concentration of Cd and As measured in plant organs, and that As concentration was the most relevant variable. Joint effects on plant growth were additive or synergistic, whereas joint genotoxic effects were additive or antagonistic. The interaction between Cd and As occurred at both soil and plant level. In soil the presence of As limited the bioavailability of Cd, whereas the presence of Cd increased the bioavailability of As. Nevertheless only As biovailability determined the amount of As absorbed by plants. The amount of Cd absorbed by plant was not linearly correlated with the fraction of bioavailable Cd in soil suggesting the involvement of additional factors, such as plant uptake mechanisms. These results reveal that the simultaneous presence in soil of Cd and As, although producing an additive or synergistic toxic effect on Trifolium repens L. growth, generates a lower DNA damage.

Most of the plants employed to remove metals from contaminated soils are annuals and have a seed-to- seed life cycle of a few months, usually over spring and summer. Consequently, for most of the year, fields are not actively cleaned but are completely bare and subject to erosion by water and wind. The objective of this study was to evaluate the benefits of using Lupinus albus as a winter crop in a rotation sequence with a summer crop ideally selected for phytoextraction, such as industrial hemp. Lupin plants were grown in two alkaline soil plots (heavy metal-contaminated and uncontaminated) of approximately 400 m 2 each after the cultivation and harvest of industrial hemp. A smaller-scale parallel pot experiment was also performed to better understand the lupin behavior in increasing concentrations of Cd, Cu, Ni and Zn. White lupin grew well in alkaline conditions, covering the soil during the winter season. In few months plants were approximately 40e50 cm high in both control and contaminated plots. In fields where the bioavailable fraction of metals was low (less than 12%), plants showed a high tolerance to these contaminants. However, their growth was affected in some pot treatments in which the concen- trations of assimilable Cu, Zn and Ni were higher, ranging from approximately 40e70% of the total concentrations. The lupin's ability to absorb heavy metals and translocate them to shoots was negligible with respect to the magnitude of contamination, suggesting that this plant is not suitable for extending the period of phytoextraction. However, it is entirely exploitable as green manure, avoiding the appli- cation of chemical amendments during phytoremediation. In addition, in polluted fields, white lupin cultivation increased the soil concentration of live bacteria and the bioavailable percentage of metals. On average live bacteria counts per gram of soil were 65 10 6 ± 18 10 6 and 99 10 6 ± 22*10 6 before and after cultivation, respectively. The percentages of bio

Negli ultimi decenni si è assistito ad un progressivo incremento nella frequenza delle patologie allergiche, tanto da considerarle, attualmente, come la “nuova epidemia” del XXI secolo. Questo notevole ed inarrestabile aumento ha attirato l’attenzione della comunità scientifica e pubblica, rendendo le allergie una priorità a livello globale. Tra le malattie allergiche la pollinosi è certamente la manifestazione più comune e diffusa, soprattutto nei paesi industrializzati; è difficile stabilire la prevalenza assoluta delle pollinosi ma in Italia si stima che fino al 15% della popolazione ne sia interessata. A questo proposito, in Italia, ed in particolare nell’area piemontese e lombarda, Ambrosia artemisiifolia L. è la specie che desta maggiori preoccupazioni anche a causa della sua veloce espansione, tanto da essere considerata la seconda causa di pollinosi nel milanese. Ambrosia artemisiifolia L è una pianta erbacea invasiva alloctona a ciclo annuale, originaria del Nord America e accidentalmente introdotta in Europa in seguito all’importazione di carichi di semi di interesse agricolo all’inizio del secolo scorso. A causare allergie è l’allergene maggiore di ambrosia, Amb a 1 con le sue isoforme; proteine appartenenti alla famiglia delle pectato liasi (Amb a 1.1, Amb a 1.2, Amb a 1.3, Amb a 1.4, Amb a 1.5), che possono essere espresse nel polline. Rimane da appurare se tutte le isoforme sono espresse contemporaneamente nel polline di singole piante e quale sia l’attività immunologica delle singole isoforme. Da dati bibliografici risulta che l’ambrosia produce popolazioni verosimilmente caratterizzate da un’alta variabilità genetica tra gli individui e risulta quindi importante studiare le singole piante per comprendere i fattori genetici ed ambientali che determinano l’aggressività del polline. In questo contesto, stiamo valutando la variabilità genetica inter ed intra-popolazione dell’ambrosia in relazione alle isoforme di Amb a 1 e al loro potenziale

Background: Pollutants may affect pollen allergenicity and thus the prevalence of allergies. Although a few studies are available in literature, the connection between pollution and the allergenic potential of pollen has yet to be clearly defined. The objective of this study was to evaluate the effect of traffic-related pollution on the allergenicity of ragweed (Ambrosia artemisiifolia L.) pollen through a field-based experiment. Methods: Mature pollen grains were collected from ragweed plants grown along main roadsides and in vegetated areas of Po river plain. The percentage of subpollen particle-releasing grains (SPPGs) was evaluated immediately after sampling by microscope and image analysis. Immunochemistry and LC-MS/MS were applied to assess the whole allergenicity and the allergen pattern characterizing the different pollen samples. Results: No statistical difference was detected in the percentage of SPPGs among pollen samples. Specifically, after hydration, the mean percentage was very low (>4%) in all the samples, regardless of the site of origin. On the contrary, pollen collected along high-traffic roads showed a higher whole allergenicity than pollen from low-traffic roads and vegetated areas which showed a reactivity similar to that of the commercial pollen 'Allergon', used as a standard. The detected higher allergenicity levels were attributed to both quantitative and qualitative differences in allergen pattern. Conclusion: Our findings show that pollen collected at different sites contains different amount and number of allergens and suggest that traffic-related pollution enhances ragweed pollen allergenicity, which may contribute to the increasing prevalence of ragweed allergy in Lombardy plain. © 2012 John Wiley & Sons A/S.

Environmental  pollutants  may  affect  the  allergenicity  of  pollen  and  thus  the  prevalence  of  allergies.  Although  a  few  of  studies  are  available  in  literature,  the  connection  between  pollution  and  the  allergen  content of pollen has yet to be clearly defined.  Lombardy, a highly populated Italian region, is considered one of the most polluted area all over the world.  In this region, the behavior of the alien plant Ambrosia artemisiifolia L. is of great concern: it has rapidly  spread in recent years and it has become the second cause of allergy in a short time.   The  objective  of  this  work  was  to  evaluate  the  role  of  traffic  related  pollution  on  the  allergenicity  of  ragweed  pollen.  The  sub‐pollen‐particles  release,  the  whole  allergenicity  and  the  allergen  pattern  were  determined  in  ragweed  pollen  samples,  collected  in  vegetated  areas  and  along  high  traffic  roads.  Concerning  sub‐pollen‐particles  release,  no  statistically  significant  difference  was  found  among  samples.  Specifically,  after  hydration,  in  all  samples,  regardless  to  the  site  of  origin,  the  percentage  of&nb

Peach softening is usually attributed to the dismantling of the cell wall in which endo-polygalacturonase (endo-PG)- catalysed depolymerization of pectins plays a central role. In this study, the hypothesis that the function of endo-PG is critical for achieving a melting flesh fruit texture but not for reducing fruit firmness was tested by comparing pericarp morphology and endo-PG expression and localization in melting (MF) and non-melting flesh (NMF) fruit at successive stages of ripening. MF Bolero, Springbelle, and Springcrest, and NMF Oro-A and Jonia cultivars were analysed. Both MF and NMF fruit were left to ripen on the tree and reached a firmness of <10 Newtons (N). The image analysis of pericarp tissues revealed that during softening the loss of cell turgidity was a process common to mesocarp cells of all MF and NMF fruit and was clearly visible in peaches with a firmness of less than ;20 N. In contrast, the loss of cell adhesion was a feature exclusively observed in ripe MF fruit pericarp. In this ripe fruit, large numbers of endo-PG isoforms were highly expressed and the enzyme localization corresponded to the middle lamella. As a consequence, wide apoplastic spaces characterized the pericarp of ripe MF peaches. In contrast, no loss of cell adhesion was observed in any NMF fruit or in unripe MF peaches. Accordingly, no endo-PG was detected in unripe NMF fruit, whereas few and poorly expressed enzyme isoforms were revealed in ripe NMF and in unripe MF peaches. In this fruit, the poorly expressed endo-PG localized mainly in vesicles within the cytoplasm and inner primary cell wall. On the whole the results suggested that endo-PG function was needed to achieve melting flesh texture, which was characterized by wide apoplastic spaces and partially deflated mesocarp cells. Conversely, endo-PG activity had no critical influence on the reduction of fruit firmness given the capacity of NMF peaches to soften, reaching values of 5–10 N. As in tomato, the change of sy

Negli ultimi decenni si è assistito ad un progressivo incremento nella frequenza delle patologie allergiche, tanto che queste stanno assumendo sempre più le caratteristiche di vere e proprie malattie del progresso. Tra di esse, la pollinosi è una delle manifestazioni più comuni e in Italia si stima che fino al 15% della popolazione ne sia interessata. L’inquinamento sembra essere uno dei fattori a cui imputare questo recente incremento; è noto, infatti, che da un lato esso esercita effetti negativi sulla salute umana, soprattutto a carico delle vie respiratorie e, dall’altro, è in grado di modificare direttamente il polline, importante fonte di allergeni. Anche in Italia, come in tutto il resto del mondo, la tematica dell’inquinamento ha assunto una rilevanza sempre maggiore e la Lombardia, regione fortemente antropizzata, è considerata oggi una delle zone più inquinate di tutto il pianeta. In questo contesto desta particolare interesse il caso di Ambrosia artemisiifolia L., una pianta erbacea, originaria del Nord America, che in tempi recenti ha subito una rapida diffusione, tanto da divenire in breve tempo la seconda causa di allergia della regione, dopo le graminacee. Obiettivo di questo progetto è quello di valutare eventuali differenze nell’allergenicità del polline di piante di Ambrosia artemisiifolia L., cresciute in aree della Lombardia a diverso grado di inquinamento. A tal scopo è stata attuata una campagna di campionamento in 10 diverse aree lombarde, selezionate in base ai dati relativi al livello di urbanizzazione, inquinamento atmosferico, distribuzione della pianta e diffusione dei pollini. Il polline raccolto nelle diverse aree è stato immediatamente analizzato al microscopio ottico per rilevare possibili differenze morfologiche e per misurare un eventuale diverso comportamento nel rilascio di materiale citoplasmatico (SPP, subpollen particle) contenente allergeni. In tutti i campioni, indipendentemente dal sito di provenienza, le analisi