Il gruppo di Achillea millefolium L. in Friuli Venezia Giulia

Abstract \u2013 Achillea millefolium L. group in Friuli Venezia Giulia. On the basis of herbarium specimens from the public collection of: i) Civic Museum of Natural History of Triest, ii) Museum of Natural History of Friuli, iii) Triest University herbarium; a revision of taxa referring to Achillea millefolium group in Friuli Venezia Giulia was performed. A total of 318 herbarium sheets has been considered. The work allowed to confirm the presence of 8 taxa already defined in literature. For each taxon a putative distribution map has been drawn, evidencing the rarity of A. pannonica e A. setacea. Furthermore, the presence of A. pratensis (recently proposed) was considered. Taken the information from herbarium labels, ecological and biogeographical traits were discussed. Key words: Achillea, distribution, Friuli Venezia Giulia, Herbarium specimen. Sommario - Partendo dai campioni d\u2019erbario depositati presso le collezioni del Museo Civico di Storia Naturale di Trieste, del Museo Friulano di Storia Naturale di Udine e dell\u2019Universit\ue0 di Trieste \ue8 stata effettuata una ricognizione dei taxa appartenenti al gruppo di Achillea millefolium in Friuli Venezia Giulia. Sono stati considerati 318 fogli d\u2019erbario complessivi, che hanno permesso di confermare la presenza di 8 entit\ue0 tassonomiche proposte precedentemente in letteratura. Sono state ottenute delle mappe putative di distribuzione che mettono in luce la rarit\ue0 di A. pannonica e A. setacea. Inoltre, \ue8 stata considerata la presenza di A. pratensis (entit\ue0 recentemente proposta). Alla luce delle informazioni presenti nei cartellini, sono state discusse le caratteristiche ecologiche e biogeografiche

Molecular study on Senecio fontanicola (S. doria group, Asteraceae) and its conservation status

Senecio fontanicola is endemic to black-bog-rush fens of southern Austria, north-western Slovenia and north-eastern Italy. It is characterized by oblanceolate leaves, a low number of supplementary bracts and glabrous achenes and it grows in marshy spring areas, fens and reed beds, between elevations from 20 to 850 m . The species was never described with molecular traits and during the last decades, S. fontanicola showed a dramatic decline due to land reclamation for agriculture. Therefore, the present study aims to characterize S. fontanicola using the molecular barcoding technique and to updated its distribution to propose a global risk category for the species, based on IUCN criteria. The three molecular markers  used in this study (trnH-psbA, rbcL, and ITS) clearly distinguished S. fontanicola from S. doria. s.s.and the revised distribution allowed the definition of the conservation status of the species, that is Endangered-EN B2ab(i,ii,iii,iv) following the B criterion of the IUCN guidelines

Molecular study on Senecio fontanicola (S. doria group, Asteraceae) and its conservation status

Senecio fontanicola is endemic to black-bog-rush fens of southern Austria, north-western Slovenia and north-eastern Italy. It is characterized by oblanceolate leaves, a low number of supplementary bracts and glabrous achenes and it grows in marshy spring areas, fens and reed beds, between elevations from 20 to 850 m . The species was never described with molecular traits and during the last decades, S. fontanicola showed a dramatic decline due to land reclamation for agriculture. Therefore, the present study aims to characterize S. fontanicola using the molecular barcoding technique and to updated its distribution to propose a global risk category for the species, based on IUCN criteria. The three molecular markers  used in this study (trnH-psbA, rbcL, and ITS) clearly distinguished S. fontanicola from S. doria. s.s.and the revised distribution allowed the definition of the conservation status of the species, that is Endangered-EN B2ab(i,ii,iii,iv) following the B criterion of the IUCN guidelines

Stand age, degree of encroachment and soil characteristics modulate changes of C and N cycles in dry grassland soils invaded by the N2-fixing shrub Amorpha fruticosa.

The N2-fixing shrub Amorpha fruticosa L. is rapidly spreading in the dry riparian natural grasslands of Europe, altering ecosystem functions and depleting plant diversity. Alteration of the N cycle represents the key factor involved in invasions by N2-fixing plants with cascading effects on plant species richness. We hypothesized that A. fruticosa encroachment strongly impacts not only the N but also the C cycle and that the magnitude of such alterations may be modulated by soil characteristics. To test these hypotheses, we selected four river floodplains in North East of Italy and compared natural uninvaded grasslands with half invaded and completely invaded sites, based on A. fruticosa stand characteristic and relevant leaf traits and on soil properties related to soil texture and to C and N cycles. Soil organic matter mineralisation, ammonification and nitrification rates were determined. Soil nitrification increased remarkably with plant invasion while ammonification was significantly higher only in half invaded sites. Soil organic matter mineralisation, microbial biomass C sustained per soil organic C unit and nitrification positively correlated with stand age, regardless to the stage of the encroachment. Mineralisation and nitrification increased with soil organic C and total N in uninvaded and completely invaded sites, but decreased in half invaded sites. At the half invasion stage, trends in nitrification and CO2 mineralisation were transitionally reverted and remediation may be facilitated by less pronounced changes in soil properties compared to completely invaded sites. Direct effects of plant invasion are modulated by the action of soil characteristics such as soil organic C and clay contents, with soils rich in organic C showing larger nitrification and mineralisation rates

Flavonoids and darkness lower PCD in senescing Vitis vinifera suspension cell cultures

Background Senescence is a key developmental process occurring during the life cycle of plants that can be induced also by environmental conditions, such as starvation and/or darkness. During senescence, strict control of genes regulates ordered degradation and dismantling events, the most remarkable of which are genetically programmed cell death (PCD) and, in most cases, an upregulation of flavonoid biosynthesis in the presence of light. Flavonoids are secondary metabolites that play multiple essential roles in development, reproduction and defence of plants, partly due to their well-known antioxidant properties, which could affect also the same cell death machinery. To understand further the effect of endogenously-produced flavonoids and their interplay with different environment (light or dark) conditions, two portions (red and green) of a senescing grapevine callus were used to obtain suspension cell cultures. Red Suspension cell Cultures (RSC) and Green Suspension cell Cultures (GSC) were finally grown under either dark or light conditions for 6 days. Results Darkness enhanced cell death (mainly necrosis) in suspension cell culture, when compared to those grown under light condition. Furthermore, RSC with high flavonoid content showed a higher viability compared to GSC and were more protected toward PCD, in accordance to their high content in flavonoids, which might quench ROS, thus limiting the relative signalling cascade. Conversely, PCD was mainly occurring in GSC and further increased by light, as it was shown by cytochrome c release and TUNEL assays. Conclusions Endogenous flavonoids were shown to be good candidates for exploiting an efficient protection against oxidative stress and PCD induction. Light seemed to be an important environmental factor able to induce PCD, especially in GSC, which lacking of flavonoids were not capable of preventing oxidative damage and signalling leading to senescence

Soil properties and plant community relationship in a saltmarsh of the Grado and Marano lagoon (northern Italy)

7noPurpose: The relationship between soil properties and plant communities was investigated in a saltmarsh of the Grado and Marano lagoon (northern Italy), where hydrology and micromorphology strongly influence the features of the ecosystem. A multidisciplinary approach was used to assess the change of soil properties and plant communities in relation to the submergence of soil. Materials and methods: The plant community and soil profile surveys were both carried out along a transect in six sampling sites of the Gran Chiusa saltmarsh (Grado and Marano lagoon). The morphological and physicochemical parameters of soil profiles were investigated, and soils were classified according to Soil Taxonomy. The concentration of macronutrients in both soils and plants was analysed by inductively coupled plasma-optical emission spectrometry. Cluster and linear discriminant analysis were used to assist the interpretation of the data of plant communities and soil properties, respectively. The bioconcentration factor explored the macronutrient relationship between plant community and soil. Results and discussion: A high, middle and low zone were identified by clustering the different plant communities along the studied transect. Discriminant analysis showed how the increase in soil submergence supported the accumulation of S and Ca content and depletion of Fe and Na. The development of different plant communities was linked to both soil water saturation and to the capacity of halophytes to tolerate anoxic conditions or salinity, by extrusion or bioconcentration strategies. Conclusions: This study demonstrates that tide level plays an important role in the pedological development and chemical transformations along a soil hydrosequence. The micromosaic vegetation pattern may therefore represent a useful index of the hydrological and nutritional status of the underlying soils and could be used to predict changes in coastal ecosystems. © 2016, Springer-Verlag Berlin Heidelberg.openopenVittori Antisari, Livia; Ferronato, Chiara; Pellegrini, Elisa; Boscutti, Francesco; Casolo, Valentino; de Nobili, Maria; Vianello, GilmoVittori Antisari, Livia; Ferronato, Chiara; Pellegrini, Elisa; Boscutti, Francesco; Casolo, Valentino; DE NOBILI, Maria; Vianello, Gilm

Transient Effects of Snow Cover Duration on Primary Growth and Leaf Traits in a Tundra Shrub

With the recent climate warming, tundra ecotones are facing a progressive acceleration of spring snowpack melting and extension of the growing season, with evident consequences to vegetation. Along with summer temperature, winter precipitation has been recently recognised as a crucial factor for tundra shrub growth and physiology. However, gaps of knowledge still exist on long-living plant responses to different snowpack duration, especially on how intra-specific and year-to-year variability together with multiple functional trait adjustments could influence the long-term responses. To fill this gap, we conducted a 3 years snow manipulation experiment above the Alpine treeline on the typical tundra species Juniperus communis, the conifer with the widest distributional range in the north emisphere. We tested shoot elongation, leaf area, stomatal density, leaf dry weight and leaf non-structural carbohydrate content of plants subjected to anticipated, natural and postponed snowpack duration. Anticipated snowpack melting enhanced new shoot elongation and increased stomatal density. However, plants under prolonged snow cover seemed to compensate for the shorter growing period, likely increasing carbon allocation to growth. In fact, these latter showed larger needles and low starch content at the beginning of the growing season. Variability between treatments slightly decreased over time, suggesting a progressive acclimation of juniper to new conditions. In the context of future warming scenarios, our results support the hypothesis of shrub biomass increase within the tundra biome. Yet, the picture is still far from being complete and further research should focus on transient and fading effects of changing conditions in the long term

The permeability transition in plant mitochondria: The missing link

The synthesis of ATP in mitochondria is dependent on a low permeability of the inner membrane. Nevertheless, mitochondria can undergo an increased permeability to solutes, named permeability transition (PT) that is mediated by a pore (PTP). PTP opening requires matrix Ca2+ and leads to mitochondrial swelling and release of intramembrane space proteins (e.g. cytochrome c). This feature has been initially observed in mammalian mitochondria and tentatively attributed to some components present either in the outer or inner membrane. Recent works on mammalian mitochondria point to mitochondrial ATP synthase dimers as physical basis for PT, a finding that has been substantiated in yeast and Drosophila mitochondria. In plant mitochondria, swelling and release of proteins have been linked to programmed cell death, but in isolated mitochondria PT has been observed in only a few cases and in plant cell cultures only indirect evidence is available. The possibility that mitochondrial ATP synthase dimers could function as PTP also in plants is discussed here on the basis of the current evidence. Finally, a hypothetical explanation for the origin of PTP is provided in the framework of molecular exaptation

Investigation of non-structural carbohydrates and xylem anatomy in petiole of grapevine varieties during water limitation and after re-irrigation

Water shortage (WS) during growing of Vitis vinifera L. can limit shoot growth and affect yield and fruit quality, as well as allocation of carbon reserves into perennial organs for the upcoming years. Varietal anatomical differences, such as specific mean xylem vessel diameter in petiole, are expected to influence water transport in canes facing water limitation. Several authors have also evidenced that non-structural carbohydrates (NSC) of adjacent living parenchyma are involved in the repair mechanism of embolized vessels. In this work, we evaluated NSC level and xylem anatomy in petiole of Cabernet Sauvignon and Syrah varieties, subjected to WS and subsequent water refilling in the summer of 2017. The anatomical analysis highlighted that Syrah had high frequency of classes of large vessels, and that the xylem differentiation of vascular bundles was also affected by WS. Moreover, petiole NSC content was significantly influenced by WS and recovery, supporting the hypothesis that starch mobilization was associated to an elevated concentration in soluble NSC. This effect was determinant for Cabernet Sauvignon, whose stress response seemed to be based mainly on NSC metabolism. Finally, Syrah, differently to Cabernet Sauvignon, sustained the WS-induced increase in soluble NSC of petiole also 18 h after re-watering