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International audience; Saxifraga florulenta is a monocarpic species endemic to SW Alps, whose reproductive biology is still unknown. Its knowledge may provide useful information on how the species may face the global warming. In this study, we investigated the plant-pollinator interactions and the mating system of the plant. We described the phenology of the inflorescences, we evaluated the type of pollinators, we verified self and cross-pollination and lastly we quantified the reproductive success of the plants. In spite of the low visitation rate of pollinators, S. florulenta shows high fruit set and seed set. The plant exhibits a prolonged flowering period and has a definite inflorescence, characterized by a sequential blooming bearing both female-or male-phase flowers at the same time; in addition, flowers show a delayed maturation and movement of stamens. These floral and inflorescence traits lead to a mixed reproduction mode which guarantees reproductive success by adopting the "best of two worlds" strategy. The species maximizes its resource investment by having inflorescence size and number of flowers directly related to plant size, whilst fruit and seed set as well as seeds per flower did not show any statistically significant relationship with plant size.

Research is revealing an increasing number of positive effects of nature for humans. At the same time, biodiversity in cities, where most humans live, is often low or in decline. Tangible solutions are needed to increase urban biodiversity. Architecture is a key discipline that has considerable influence on the built-up area of cities, thereby influencing urban biodiversity. In general, architects do not design for biodiversity. Conversely, urban conservation planning generally focuses on the limited space free of buildings and does not embrace architecture as an important discipline for the creation of urban green infrastructure. In this paper, we argue that the promotion of biodiversity needs to become a key driving force of architectural design. This requires a new multi-species design paradigm that considers both human and non-human needs. Such a design approach needs to maintain the standards of the architectural profession, including the aim to increase the well-being of humans in buildings. Yet, it also needs to add other stakeholders, organisms such as animals, plants and even microbiota. New buildings designed for humans and other inhabitants can then increase biodiversity in cities and also increase the benefits that humans can derive from close proximity to nature. We review the challenges that this new design approach poses for both architecture and ecology and show that multi-species-design goes beyond existing approaches in architecture and ecology. The new design approach needs to make ecological knowledge available to the architectural design process, enabling practitioners to find architectural solutions that can facilitate synergies from a multi-species perspective. We propose that a first step in creating such a multi-species habitat is the design of buildings with an ecolope, a multi criteria-designed building envelope that takes into account the needs of diverse organisms. Because there is no framework to design such an ecolope, we illustrate how multi-species design needs to draw on knowledge from ecology, as well as architecture, and design computation. We discuss how architectures designed via a multi-species approach can be an important step in establishing beneficial human–nature relationships in cities, and contribute to human well-being and biodiversity conservation. Read the free Plain Language Summary for this article on the Journal blog.

The co-growth and synergistic interactions among fungi and bacteria from the rhizosphere of plants able to hyper accumulate potentially toxic metals (PTMs) are largely unexplored. Fungi and bacteria contribute in an essential way to soil biogeochemical cycles mediating the nutrition, growth development, and health of associated plants at the rhizosphere level. Microbial consortia improve the formation of soil aggregates and soil fertility, producing organic acids and siderophores that increase solubility, mobilization, and consequently the accumulation of nutrients and metals from the rhizosphere. These microorganism consortia can both mitigate the soil conditions promoting plant colonization and increase the performance of hyperaccumulator plants. Indeed, microfungi and bacteria from metalliferous soils or contaminated matrices are commonly metal-tolerant and can play a key role for plants in the phytoextraction or phytostabilization of metals. However, few works deepen the effects of the inoculation of microfungal and bacterial consortia in the rhizosphere of metallophytes and their synergistic activity. This mini-review aimed to collect and report the data regarding the role of microbial consortia and their potentialities known to date. Moreover, our new data had shown an active fungal-bacteria consortium in the rhizosphere of the hyperaccumulator plant Alyssoides utriculata.

This study faces the characterization of the culturable microbiota of the facultative Ni-hyperaccumulator Alyssoides utriculata to obtain a collection of bacterial and fungal strains for potential applications in Ni phytoextraction. Rhizosphere soil samples and adjacent bare soil associated with A. utriculata from serpentine and non-serpentine sites were collected together with plant roots and shoots. Rhizobacteria and fungi were isolated and characterized genotypically and phenotypically. Plants and soils were analyzed for total element concentration using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Serpentine and non-serpentine sites differ in terms of elements concentration in soil, plant roots and shoots. Ni and Co are significantly higher on serpentine site, while Ca is more abundant in non-serpentine site. Bacteria and fungi were significantly more abundant in rhizosphere than in bare soil and were dominated by genera Arthrobacter, Bacillus and Streptomyces, Penicillium and Mucor. The genus Pseudomonas was only found in rhizospheric serpentine soils (2% of total serpentine isolates) and with Streptomyces sp. showed highest Ni-tolerance up to 15 mM. The same occurred for Trichoderma strain, belonging to the harzianum group (2% of the total microfungal count) and Penicillium ochrochloron (10% of the total microfungal count, tolerance up to Ni 20 mM). Among serpentine bacterial isolates, 8 strains belonging to 5 genera showed at least one PGPR activity (1-Aminocyclopropane-1-Carboxylic Acid (ACC) deaminase activity, production of indole-3-acetic acid (IAA), siderophores and phosphate solubilizing capacity), especially genera Pantoea, Pseudomonas and Streptomyces. Those microorganisms might thus be promising candidates for employment in bioaugmentation trials.

Vegetables represent a major source of Ni exposure. Environmental contamination and cultural practices can increase Ni amount in tomato posing significant risk for human health. This work assesses the tomato (Solanum lycopersicum L.) response to Ni on the agronomic yield of fruits and the related production of allergens.Two cultivars were grown in pots amended with Ni 0, 30, 60, 120, and 300 mg kg-1, respectively. XRF and ICP-MS analyses highlighted the direct increase of fruit Ni content respect to soil Ni, maintaining a stable biomass. Leaf water content increased at Ni 300 mg kg-1. Total protein content and individual allergenic components were investigated using biochemical (RP-HPLC and N-terminal amino acid sequencing) and immunological (inhibition tests of IgE binding by SPHIAa assay on the FABER® testing system) methodologies. Ni affected the fruit tissue concentration of pathogenesis-related proteins and relevant allergens (LTP, profilin, Bet v 1-like protein and TLP). This study elucidates for the first time that tomato reacts to exogenous Ni uptaking metal while changing its allergenic profiles, with potential double increasing of exposure risks for consumers. This evidence highlighted the importance of adequate choice of low-Ni tomato cultivars and practices to avoid Ni uptake by potentially contaminated matrices.

Is it possible to improve the efficiency of bioremediation technologies? The use of mixed cultures of bacteria and fungi inoculated at the rhizosphere level could promote the growth of the associated hyperaccumulating plant species and increase the absorption of metals in polluted soils, broadening new horizons on bioremediation purposes. This work investigates interactions between Ni-tolerant plant growth-promoting bacteria and fungi (BF) isolated from the rhizosphere of a hyperaccumulating plant. The aim is to select microbial consortia with synergistic activity to be used in integrated bioremediation protocols. Pseudomonas fluorescens (Pf), Streptomyces vinaceus (Sv) Penicillium ochrochloron (Po), and Trichoderma harzianum group (Th) were tested in mixes (Po-Sv, Po-Pf, Th-Pf, and Th-Sv). These strains were submitted to tests (agar overlay, agar plug, and distance growth co-growth tests), tailored for this aim, on Czapek yeast agar (CYA) and tryptic soy agar (TSA) media and incubated at 26 ± 1°C for 10 days. BF growth, shape of colonies, area covered on plate, and inhibition capacity were evaluated. Most BF strains still exhibit their typical characters and the colonies separately persisted without inhibition (as Po-Sv) or with reciprocal confinement (as Th-Sv and Th-Pf). Even if apparently inhibited, the Po-Pf mix really merged, thus obtaining morphological traits representing a synergic co-growth, where both strains reached together the maturation phase and developed a sort of mixed biofilm. Indeed, bacterial colonies surround the mature fungal structures adhering to them without any growth inhibition. First data from in vivo experimentation with Po and Pf inocula in pot with metalliferous soils and hyperaccumulator plants showed their beneficial effect on plant growth. However, there is a lack of information regarding the effective co-growth between bacteria and fungi. Indeed, several studies, which directly apply the co-inoculum, do not consider suitable microorganisms consortia. Synergic rhizosphere BFs open new scenarios for plant growth promotion and soil bioremediation.

The soil–root interface is the micro-ecosystem where roots uptake metals. However, less than 10% of hyperaccumulators’ rhizosphere has been examined. The present study evaluated the root and shoot response to nickel in hyperaccumulator and non-hyperaccumulator species, through the analysis of root surface and biomass and the ecophysiological response of the related aboveground biomass. Ni-hyperaccumulators Alyssoides utriculata (L.) Medik. and Noccaea caerulescens (J. Presl and C. Presl) F.K. Mey. and non-hyperaccumulators Alyssum montanum L. and Thlaspi arvense L. were grown in pot on Ni-spiked soil (0–1000 mg Ni kg−1, total). Development of root surfaces was analysed with ImageJ, fresh and dry root biomass was determined. Photosynthetic efficiency was performed by analysing the fluorescence of chlorophyll a to estimate the plants’ physiological conditions at the end of the treatment. Hyperaccumulators did not show a Ni-dependent decrease in root surfaces and biomass (except Ni 1000 mg kg−1 for N. caerulescens). The non-hyperaccumulator A. montanum suffers metal stress which threatens plant development, while the excluder T. arvense exhibits a positive ecophysiological response to Ni. The analysis of the root system, as a component of the rhizosphere, help to clarify the response to soil nickel and plant development under metal stress for bioremediation purposes.

According to projects and practices that the Italian botanists and ecologists are carrying out for bringing “more nature in the city”, new insights for a factual integration between ecological perspectives and more consolidated aesthetic and agronomic approaches to the sustainable planning and management of urban green areas are provided.

Abandoned industrial sites and mines may constitute possible hazards for surrounding environment due to the presence of toxic compounds that may contaminate soils and waters. The possibility to remove metal contaminants, specifically nickel (Ni), by means of fungi was presented exploiting a set of fungal strains isolated from a Ligurian dismissed mine. The achieved results demonstrate the high Ni(II) tolerance, up to 500 mg Ni l

Vertical greening systems and green roofs provide ecosystem services in the urban context. Despite the important benefits they provide, economic (initial and maintenance costs) and environmental issues may limit the widespread diffusion of these greening systems. Mosses can be a low-cost and low-maintenance alternative green envelope for large-scale application on existing urban and industrial buildings thanks to their low requirements in terms of growing substrates, low amount of water and nutrients needed, and high desiccation tolerance. The study assesses the’ growing ability of mosses on building materials and low-cost materials, by means of growing tests performed under controlled environmental conditions on horizontal and vertical surfaces. Moss growth depends mainly on the physical characteristics of the materials, although an acidic moss mixture improves species richness. Results show different surface coverage: capillary matting > cement plaster > lime plaster > terracotta brick > slate > quartzite. The water retention capacity and its homogeneous distribution on the growing surface are the limiting factors for moss growth.

In this chapter, the mitigation effect of greening solutions on air pollution within urban canyons is reviewed. First, a glance at the specific scientific literature is made and the different outcomes by authors about the effectiveness of greening solutions on air quality improvements are stressed. The main parameters to consider, the most promising strategies and the most suitable plant species characteristics, are discussed. Considering the important role played by numerical simulation in this field, the main issues that have to be taken into account in implementing a computational fluid dynamics model of the problem are listed and commented. Finally, with reference to evergreen hedges and a row of trees, some preliminary results obtained by means of a simple numerical model applied to CO 2 are presented and discussed.

Applying vertical greening systems (VGS) on both new and existing buildings can offer multiple environmental benefits, including air pollutants’ mitigation and air quality improvement. The direct effects of VGS on air quality are mainly related to the absorption of fine dust particles and the uptake of gaseous pollutants. Indirect effects, e.g., cooling capacity and related reduction of energy demand and gas emissions connected, can be relevant as well. VGS can therefore reduce adverse health impacts from long term exposure to air pollutants at the same time improving the local urban environment. Selecting the most suitable plant species is of key importance, especially considering particulate matter collecting capacity. Attention should be also paid in low allergenicity, low cost of maintenance, and climatic suitability.

Reduction of pollen flow can affect plant abundance and population viability and cause selection on plant mating system and floral traits. Little is known on the effect of this phenomenon in species naturally restricted to small and isolated habitats, that may have developed strategies to cope with long-term isolation and small population size. We investigated the pollination ecology of the endemic distylous winter-flowering P. allionii to verify the possible limitation of female fitness due to reduced pollinator visits. We recorded a higher production of pollen grains in long-styled morph, and a higher seed set in short-styled morph. The high intra-morph variability of sexual organ position may explain the hybridization phenomena allowing and easier intra-morph pollination. The fruit set is constant, although its winter-flowering period might decrease pollen transfer. Nevertheless, the lower competition for pollinators with neighbouring plants and the long-lasting anthesis may offset its reproductive success. Even if our results show no evidence of imminent threats, changes in plant-pollinator interactions might increase inbreeding, resulting in an increased extinction risk.

Urban vegetation has been shown to improve air quality. Green envelopes can provide wide vegetated surfaces in dense cities. This research investigates the performances of four selected plant species used for vertical greening systems, comparing the fine and ultrafine dusts (PM10, PM2.5) collecting capacity by leaves, under the same conditions (height/location, pollution exposition, weather). The ESEM micrographs (n = 144) taken on the upper leaf epidermis of 20 leaves show different plant species performances, with Trachelospermum jasminoides > Hedera helix > Cistus ‘Jessamy Beauty’ > Phlomis fruticosa. The 100×, 250×, 500×, 2500× magnifications allow counting a wide range of particle sizes, i.e., from 0.1 to 20 μm. The study demonstrates that some variable investigated, i.e., plant species’ shape and surface (thick cuticular waxes on leaf epidermis), influence the amount of particles deposed; while others, i.e., season and age of leaves, do not. This study demonstrates that selecting specific plants in green infrastructure is important to exploit their collecting capacity to increase vertical greening systems performances.

Plants growing under zinc excess store it in leaves, the organs in charge with carbon assimilation. Therefore, leaf modifications can help to understand the plant responses to environmental stresses. In this study, we tested the hypothesis that high zinc concentration can affect leaf anatomy and physiology of Populus alba cv. Villafranca, a tree species with interesting perspectives of application in phytoremediation. Plants were supplemented or not with 300 mg zinc per kg of soil and grown for six months. Green and macroscopically symptom-less leaves from poplars of each treatment were analyzed by light and electron microscopy (TEM, SEM-EDS) and by Raman spectroscopy. LHCII and D1–D2 protein expression were considered to evaluate PSII functioning. Zinc was histochemically detected in the leaves. Zinc strongly altered leaf morphology and ultrastructure, and negatively affected PSII activity decreasing D1 and D2, but not LHCII, protein expression. Zinc was mostly detected in the cell walls of the xylem and of the parenchyma cells surrounding the bundles of zinc treated plants, but not in the controls. A significant increase in the number of calcium oxalate crystals was observed in the leaves of zinc treated plants, but the latter metal was not incorporated in crystals, suggesting an increase of free calcium following zinc accumulation in the cell walls.

This study evaluated relationships between the serpentine soil from a waste-rock dump of the abandoned Libiola sulphide mine (NW Italy) and its pioneer vegetation. We identified the tolerance of various species to environmental conditions and evaluated physical or chemical factors that influenced the first plants to colonize this stressful environment. Thirteen sampling sites were identified in the rock dump from characterization of surface or near-surface oxidation zone and vegetation type. Sampling sites were analyzed for slope, pH, mineralogy, soil chemistry, floristic composition, and the percent coverage of each species. In all the plots, species richness and vegetation cover were extremely low. The flora showed an acidophilous character.

The function of diaspores in Moehringia genus was investigated and field observations pointed out the elaiosome role in seed predation and dispersal by ants. Histochemical stainings underlined the presence of lipid in the strophiole. Our results are congruent with the hypothesis that some representatives of the genus Moehringia adopt myrmecochory, especially those species that prefer rocky habitats. Strophiole dimensions and oil content volume seem to influence seed predation in plants by ants. However, the interaction of further abiotic dispersal agents (wind, water) may increase and make more efficient the dissemination strategies.

High nickel (Ni) levels exert toxic effects on plant growth and plant water content, thus affecting photosynthesis. In a pot experiment, we investigated the effect of the Ni concentration on the physiological characteristics of the Ni hyperaccumulator Alyssoides utriculata when grown on a vermiculite substrate in the presence of different external Ni concentrations (0-500 mg Ni L(-1)). The results showed that the Ni concentration was higher in leaves than in roots, as evidenced by a translocation factor = 3 and a bioconcentration factor = 10. At the highest concentration tested (500 mg Ni L(-1)), A. utriculata accumulated 1100 mg Ni per kilogram in its leaves, without an effects on its biomass. Plant water content increased significantly with Ni accumulation. Ni treatment did not, or only slightly, affected chlorophyll fluorescence parameters. The photosynthetic efficiency (FV/FM) of A. utriculata was stable between Ni treatments (always ≥ 0.8) and the photosynthetic performance of the plant under Ni stress remained high (performance index = 1.5). These findings support that A. utriculata has several mechanisms to avoid severe damage to its photosynthetic apparatus, confirming the tolerance of this species to Ni under hyperaccumulation.

The primary causes of soil contamination are intensive industrial activities and inade‐ quate waste disposal and treatment (although these categories vary widely across Eu‐ rope) [1]. Good knowledge of the content and variability of metals in soils linked to both the contribution of parent rock (lithogenic sources) and human activities (anthropogenic sources) is also necessary for evaluating metal pollution. These tasks are particularly difficult to achieve in ancient populated areas, such as the European Mediterranean region, where unpolluted soils are almost impossible to find [2, 3]. Among anthropogenic sour‐ ces, mining activities are the fourth largest source of land pollution (e.g., 7% of the National Priority (Superfund) Sites in the USA; [4]).

The development of isidia in thalli of Pseudevernia furfuracea from the Carnic Alps (North-eastern Italy), and the effects of these structures on CO2 gas exchanges were investigated. The ontogenetic events were studied by comparison of sections stained with different histochemical tests and SEM observations. A high cell turnover rate in both symbiotic partners is the first sign of isidium development, followed by an increased aplanosporogenesis of algae and growth of neighbouring medullary hyphae which become oriented upwards. Large nuclei and an intense cytoplasm activity characterize the mycobiont cells. The surface of very young isidia shows an irregular structure of spherical to ovoid protruding tips of perpendicular cortical hyphae, that are later organised in a pseudomeristematic area similar to that observed in the apex of growing lobes. CO2 gas exchange measurements carried out in the laboratory confirmed the high metabolic activity of isidia. At optimal water content and favourable light conditions, isolated isidia had rates of gross photosynthesis and dark respiration that were twice those of non-isidiate lobes. Isolated isidia also had a very low CO2 saturation point, probably because of their favourable surface/volume ratio, and a high light saturation, probably linked to their high content of photosynthetic pigments. The different roles played by isidia in the biology of Pseudevernia furfuracea, and particularly their rejuvenating effect on aged lobes, are discussed, and the presence of thalloconidia is briefly mentioned.

Thymelaea hirsuta is a circum-Mediterranean subdioecious shrub used to model the evolutionary pathway from heterodichogamy to dioecy. Since discordant data on the pollination mechanism of this plant have been reported, in this study we have tried to clarify the complex of features and events involved in the breeding system of this species at the Northern edge of its range (Tyrrhenian coast, Italy and France). Flower and pollen features related to pollination mechanism were analyzed, and the seasonal presence of insects visiting the plant was monitored. Despite the presence of small pollen grains, normally associated with wind pollination, the Crotonoid-pattern of exine, the large amount of pollenkitt and the presence of nectar are typical entomophilous adaptations. Among insects visiting the plant, thrips (Thysanoptera) might have a role in pollination owing to their large number and for the constant presence of T. hirsuta pollen on their body. In contrast, no evidence of anemophilous transport of pollen was obtained, clashing with reports of a wind pollination system for Egyptian populations. Based on our observations wind seems not to play a key role in the pollination process of this species in the Northern Mediterranean region, while insects might play a major role.

Copper is one of the most dangerous soil contaminants. Soils affected by high copper concentrations show low biodiversity and, above all, inadequate environmental quality. Microorganisms such as fungi can play a key role in metal-polluted ecosystems via colonization and decontamination. The study is devoted to characterize the microfungal community in highly Cu-contaminated bare soil from derelict Fe–Cu sulphide mines and to isolate microfungal strains able to tolerate and accumulate Cu. 11 Different taxa to be isolated has been isolated during two sampling campaigns (in Autumn and in Spring). Among these, Clonostachys rosea , Trichoderma harzianum , and Aspergillus alliaceus were tested at increasing Cu(II) concentrations and showed a Cu(II)-tolerance capability ranging from 100 to 400 mg L −1 . Moreover, the strains of T . harzianum and C . rosea presented a high Cu(II)-bioaccumulation capability, 19 628 and 22 222 mg kg −1 , respectively. These microfungi may be fruitfully exploited in mycoremediation protocols.

This study investigated the accumulation and distribution of nickel in the leaves and roots of the Mediterranean shrub Alyssoides utriculata to assess its potential use in phytoremediation of Ni contaminated soils. Total (AAS and ICP-MS) Ni, Ca and Mg contents were analyzed in the plants and related to their bioavailability (in EDTA) in serpentine and non-serpentine soils. To find the relationships between the soil available Ni and the Ni content of this species, we also evaluated possible interactions with Ca and Mg. The bioaccumulation factor (BF) and the translocation factor (TF) were determined to assess the tolerance strategies developed by A. utriculata and to evaluate its potential for phytoextraction or phytostabilization. The leaf Ni is higher than 1000 μg g(-1) which categorizes the species as a Ni-hyperaccumulator and a great candidate for Ni-phytoextraction purposes. In addition to the accumulation of Ni, the leaf Mg is also correlated with soil bioavailable concentrations. The Ca uptake and translocation were significantly lower in serpentine plants (higher Ni), as such, the leaf Ca is probably greatly influenced either by the soil's Ni or the soil Ca/Mg ratio. The BFs and TFs are strongly higher than 1 and generally did not significantly differed between plants from serpentine (higher Ni) and non-serpentine soils (lower Ni). The present study highlights for the first time that A. utriculata could be suitable for cleaning Ni-contaminated areas and provides a contribution to the very small volume of data available on the potential use of native Mediterranean plant species from contaminated sites in phytoremediation technologies.

Pteris vittata is known to hyperaccumulate arsenic, and a large number of studies on this fern species can be found in the literature aimed at evaluating its behavior when coexposed to other toxic elements. In the present study, P. vittata was treated with different concentrations of As and/or Cd in a hydroponic system, that is, under complete bioavailability of the elements, with the objective of investigating the effects of these two elements and their interactions. The response of the plant was evaluated by measuring As, Cd, P, and Ca concentrations in different parts of the plant. Moreover, the symptoms of phytotoxicity were assessed in terms of biomass reduction and loss of photosynthetic efficiency related to necrosis of pinnae. The concentrations of As and Cd measured in the fronds and the root system were significantly dependent on the treatment, whereas P and Ca concentrations were not affected. Interaction effects between As and Cd were observed, with maximum toxicity symptoms after treatment with both elements. This could affect the potential use of this fern for phytoremediation. Although As treatment produced a significant effect on leaves (e.g., chlorosis and necrosis), Cd treatment produced a stronger negative impact on plant health, reducing significantly the biomass and photosynthetic efficiency. Environ. Toxicol. Chem. 2012;31:1375–1380. © 2012 SETAC

Seeds of 27 species of Moehringia and four related representatives of Arenaria (old M. sect. Pseudomoehringia) were examined by scanning electron microscopy. Novel morphological features were observed in addition to those found in a previous similar study. The new information thus obtained provided new insight into the taxonomic value of discrete morphological characters considered in a recent phylogenetic context. Main Moehringia sections are undoubtedly defined by different types of strophioles, and by the corresponding testa cell features. This study also shows the different ontogenesis of hilar appendages previously attributed to Iberian taxa, now belonging to Arenaria. In addition to phylogenetic differences, ecology seems to play a role in the differentiation of seed morphological features with clear convergences among plants living on cliffs.

Phytotoxicity test were performed to evaluate their application in environmental monitoring on different substrates e.g. commercial detergents (D1, D2) and surface water from the dismissed Cu and Fe mine of Libiola (NW Italy), respectively. Seeds of Vicia faba were grown in 0, 10, 30, 60, 100 g/l of D1 and D2. Number of germinated seeds and root length, Germination iNDEX (G1) and growth inhibition (EC50) were considered. The Vicia test showed no significant differences between D1 and D2, with an EC50 of 13 g/l (11-15 95% C1) for D1 and 16 g/l (14-19 95% C1) for D2. These data were confirmed by G150) and Mitotic Index (MI) were evaluated. The Allium test showed a statistically significant inhibition of root growth at 50% and 100%. The root growth percentage decreased in a dose-related manner, with an EC50 of 87%. The MI decreased significantly only at 100% (undiluited mine water). Both phytotoxicity tests should be considered as valid ecotoxicological indicators for health and environment.

Zn uptake and compartmentalisation were studied in two ferns, the European Polypodium cambricum L., a possible Zn tolerant, and the sub-tropical Pteris vittata L., an As accumulator also able to accumulate Zn. Ferns growing in hydroponic systems were exposed to Zn concentrations ranging from non-toxic to lethal doses (0, 50, 125, 250, 500 mg kg−1 as ZnSO4). After treatments, the following analyses were made: photosynthetic efficiency (Handy PEA), anatomical symptoms (optical and scanning electron microscopy), determination of Zn in fronds, rhizome and roots (atomic emission spectrometry, ICP-AES). Both species showed high bioconcentration and bioaccumulation factors, but low translocation factor, indicating Zn sequestration in the root/rhizome system. P. cambricum was more resistant to Zn, while P. vittata suffered from unrestricted uptake leading to macro- and microscopical damages and plant death. Data suggest that P. cambricum could be suitable for phytostabilisation of Zn-contaminated soils in temperate areas.

Daphne gnidium is a circum-Mediterranean evergreen shrub. Flower and pollen features related to pollination mechanism were analyzed, and the seasonal presence of insects visiting the plant was monitored. The morphology and functionality of flowers are compatible with entomophily, as are pollen viability, which is maintained for a few hours only after anthesis, and the very short stigmatic receptivity. The reproductive fitness of the species is low and the ripening process often fails (35% collapsed embryos). While male organ functionality is fairly regular, the female organ often shows developmental arrest. The complex or transient evolutionary traits displayed by D. gnidium are comparable to those of Thymelaea hirsuta and other members of the Thymelaeaceae.

Cerastium utriense Barberis (Caryophyllaceae) is an endemic plant growing on ultramafic outcrops in northwestern Italy. Despite its great phytogeographical importance, little is known about its ecological requirements and environmental range. Thus, the main objective of the present work was to examine and clarify these aspects. On the basis of a preliminary survey on its range, 28 plots were sampled, and Ellenberg ecological indices of the flora growing with C. utriense were defined. Furthermore, on the basis of the floristic diversity and physical, chemical, and biological properties of the soils, 10 of these plots were selected and more closely investigated. This preliminary study characterized C. utriense as a strictly Ni-excluding serpentinophyte with no apparent relationship with typical chemical characteristics of serpentine soils. On the contrary, the species showed a direct association with physical traits typical of serpentine substrates.

A screening of Pteridophytes growing on serpentine and metalliferous soils in Northern Italy was carried out to assess the ability of these plants to tolerate or accumulate trace elements of toxicological interest. Few data are available on metal tolerance/accumulation of terrestrial ferns growing in the Mediterranean region, and several species presented here have never been investigated for this purpose. The trace-element composition (As, Cd, Cr, Cu, Fe, Ni, Pb, Zn) and P content of aerial parts of plants (12 fern and 2 horsetail species) and of their associated soils were measured. An analysis of the relationship between element concentrations in soil and in shoot revealed a significant correlation only for Zn (p < 0.05). Hierarchical cluster analysis based on element concentrations in plant aerial parts showed two outliers, viz. Equisetum ramosissimum Desf., showing the highest levels of Cr, Fe, Cu, Ni, and As, and Nephrolepis cordifolia C. Presl., showing the highest Pb value. The bioaccumulation factor exceeded 1 only for Cd in two species, Athyrium filix-femina and Dryopteris filix-mas. However, also in these cases the corresponding values of the metal in the shoots were below the thresholds for hyperaccumulators. The examined Pteridophytes seem to have developed their adaptation prevalently through mechanisms of tolerance based on metal exclusion. None of these plant species seem suitable for phytoextraction, but N. cordifolia, Pteridium aquilinum ssp. aquilinum, and E. ramosissimum have potential to be used for stabilization and restoration of soils rich in heavy metals.

Seeds of 30 species of Moehringia and 12 representatives of the Caryophyllaceae were examined with the Scanning Electron Microscope. High diversity was found in seed coat micromorphology, and a number of novel morphological features have been observed. Comparison with other representatives of the Caryophyllaceae has provided new insight into the potential taxonomic value of discrete morphological characters. Though many characters appear informative within Moehringia, they are affected by a high level of homoplasy when considered in a wider phylogenetic context. Smooth seed is the common condition in Moehringia, except for Eastern Balkan and Iberian species that maintain a secondary ornamentation of the testa cells resembling the plesiomorphic Caryophyllaceae-type. Five types of strophioles were recognized, in accordance with previous literature. Among these, the strophiole of the Iberian species appears very distinctive and a proper strophiole could not be verified in M. glochidisperma and M. fontqueri.

Thymelaea hirsuta is a subdioecious plant, bearing hermaphroditic (perfect) or monosexual (male or female) flowers from September to May. Flowers are grouped in a condensed raceme (capitulum) in which the flower sequence may occur within the same flowering season or from year to year; nevertheless floral variation is constant within sexually stable individuals (subgynoecious, subandroecious, protandrous and protogynous) or may vary within labile sexual forms. Sexual dimorphism in flowers is linked to the developmental arrest of male or female reproductive organs within bipotential flower buds. In the present study, we provide a morphological characterization of the flower and a detailed description of the developmental timing in hermaphroditic and unisexual flowers by using light and scanning electron microscopy. Particularly, we analyse the early development during which sexual dimorphism is established, by comparing the differentiation stages during pistil and stamen development/regression. The...

Main conclusion The heterologous expression of AtPCS1 in tobacco plants exposed to arsenic plus cadmium enhances phytochelatin levels, root As/Cd accumulation and pollutants detoxification, but does not prevent root cyto-histological damages. High phytochelatin (PC) levels may be involved in accumulation and detoxification of both cadmium (Cd) and arsenic (As) in numerous plants. Although polluted environments are frequently characterized by As and Cd coexistence, how increased PC levels affect the adaptation of the entire plant and the response of its cells/tissues to a combined contamination by As and Cd needs investigation. Consequently, we analyzed tobacco seedlings overexpressing Arabidopsis phytochelatin synthase1 gene (AtPCS1) exposed to As and/or Cd, to evaluate the levels of PCs and As/Cd, the cyto-histological modifications of the roots and the Cd/As leaf extrusion ability. When exposed to As and/or Cd the plants overexpressing AtPCS1 showed higher PC levels, As plus Cd root accumulation, and detoxification ability than the non-overexpressing plants, but a blocked Cd-extrusion from the leaf trichomes. In all genotypes, As, and Cd in particular, damaged lateral root apices, enhancing cell-vacuolization, causing thinning and stretching of endodermis initial cells. Alterations also occurred in the primary structure region of the lateral roots, i.e., cell wall lignification in the external cortex, cell hypertrophy in the inner cortex, crushing of endodermis and stele, and nuclear hypertrophy. Altogether, As and/or Cd caused damage to the lateral roots (and not to the primary one), with such damage not counteracted by AtPCS1 overexpression. The latter, however, positively affected accumulation and detoxification to both pollutants, highlighting that Cd/As accumulation and detoxification due to PCS1 activity do not reduce the cyto-histological damage. Electronic supplementary material The online version of this article (doi:10.1007/s00425-015-2428-8) contains supplementary material, which is available to authorized users.