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The excess of phosphorus in soil reduces physiological performances over time but enhances prompt recovery of salt-stressed Arundo donax plants
Cristina Gonnelli, Roberto Tognetti, Mauro Centritto, Francesco Loreto, Cecilia Brunetti, Federico Brilli, Sara Pignattelli, Susanna Pollastri, Claudia Cocozza, 2020, izvirni znanstveni članek

Opis: Arundo donax L. is an invasive grass species with high tolerance to a wide range of environmental stresses. The response of potted A. donax plants to soil stress characterized by prolonged exposure (43 days) to salinity (+Na), to high concentration of phosphorus (+P), and to the combination of high Na and P (+NaP) followed by 14 days of recovery under optimal nutrient solution, was investigated along the entire time-course of the experiment. After an exposure of 43 days, salinity induced a progressive decline in stomatal conductance that hampered A. donax growth through diffusional limitations to photosynthesis and, when combined with high P, reduced the electron transport rate. Isoprene emission from A. donax leaves was stimulated as Na+ concentration raised in leaves. Prolonged growth in P-enriched substrate did not significantly affect A. donax performance, but decreased isoprene emission from leaves. Prolonged exposure of A. donax to + NaP increased the leaf level of H2O2, stimulated the production of carbohydrates, phenylpropanoids, zeaxanthin and increased the de-epoxidation state of the xanthophylls. This might have resulted in a higher stress tolerance that allowed a fast and full recovery following stress relief. Moreover, the high amount of ABA-glucose ester accumulated in leaves of A. donax exposed to + NaP might have favored stomata re-opening further sustaining the observed prompt recovery of photosynthesis. Therefore, prolonged exposure to high P exacerbated the negative effects of salt stress in A. donax plants photosynthetic performances, but enhanced activation of physiological mechanisms that allowed a prompt and full recovery after stress.
Najdeno v: osebi
Ključne besede: Arundo donax Phosphorus Salinity Stress tolerance Biomass production
Objavljeno: 20.04.2020; Ogledov: 367; Prenosov: 0
.pdf Polno besedilo (6,60 MB)

The multi-purpose role of hairiness in the lichens of coastal environments: Insights from Seirophora villosa (Ach.) Frödén
Elisabetta Bianchi, Renato Benesperi, Ilaria Colzi, Andrea Coppi, Lorenzo Lazzaro, Luca Paoli, Alessio Papini, Sara Pignattelli, Corrado Tani, Pamela Vignolini, Cristina Gonnelli, 2019, izvirni znanstveni članek

Opis: The fruticose epiphytic lichen Seirophora villosa, strictly associated with Juniperus shrublands in the Mediterranean basin, was used to investigate the role of hairiness on a lichen thallus, as a characteristic morphological trait. We evaluated the effect of hair removal on the physiological parameters of a set of samples, during desiccation and on exposure to different salt concentrations. Hairy thalli were less affected by salt, suggesting that during dehydration, the presence of hair protects the thallus from light irradiance, oxidative stresses and the lipid peroxidation generated by free radicals, and could offer passive, but selective, water control. Our results showed that hair could not only increase thallus surface and promote water absorption when availability is low, but could also repel the salt dissolved in water by activating a passive resistance mechanism, by preventing salt entering.
Najdeno v: osebi
Ključne besede: Antioxidant activity Chlorophyll a fluorescence Juniperus shrublands Hair MDA Salt stress
Objavljeno: 20.04.2020; Ogledov: 365; Prenosov: 0
.pdf Polno besedilo (9,03 MB)

Impact of high or low levels of phosphorus and high sodium in soils on productivity and stress tolerance of Arundo donax plants
Claudia Cocozza, Federico Brilli, Laura Miozzi, Sara Pignattelli, Silvia Rotunno, Cecilia Brunetti, Cristiana Giordano, Susanna Pollastri, Mauro Centritto, Gian Paolo Accotto, Roberto Tognetti, Francesco Loreto, 2019, izvirni znanstveni članek

Opis: The potential of Arundo donax to grow in degraded soils, characterized by excess of salinity (Na+), and phosphorus deficiency (-P) or excess (+P) also coupled with salinity (+NaP), was investigated by combining in vivo plant phenotyping, quantification of metabolites and ultrastructural imaging of leaves with a transcriptome-wide screening. Photosynthesis and growth were impaired by+Na, -P and+NaP. While+Na caused stomatal closure, enhanced biosynthesis of carotenoids, sucrose and isoprene and impaired anatomy of cell walls, +P negatively affected starch production and isoprene emission, and damaged chloroplasts. Finally, +NaP largely inhibited photosynthesis due to stomatal limitations, increased sugar content, induced/repressed a number of genes 10 time higher with respect to+P and+Na, and caused appearance of numerous and large plastoglobules and starch granules in chloroplasts. Our results show that A. donax is sensitive to unbalances of soil ion content, despite activation of defensive mechanisms that enhance plant resilience, growth and biomass production of A. donax under these conditions.
Najdeno v: osebi
Ključne besede: Abiotic stress Giant reed Isoprene emission Phosphorus Salinity Transcriptome
Objavljeno: 20.04.2020; Ogledov: 360; Prenosov: 0
.pdf Polno besedilo (10,07 MB)

Under fungal attack on a metalliferous soil: ROS or not ROS? Insights from Silene paradoxa L. growing under copper stress
Cosimo Taiti, Elisabetta Giorni, Ilaria Colzi, Sara Pignattelli, Nadia Bazihizina, Antonella Buccianti, Simone Luti, Luigia Pazzagli, Stefano Mancuso, Cristina Gonnelli, 2016, izvirni znanstveni članek

Opis: We investigated how the adaptation to metalliferous environments can influence the plant response to biotic stress. In a metallicolous and a non-metallicolous population of Silene paradoxa the induction of oxidative stress and the production of callose and volatiles were evaluated in the presence of copper and of the PAMP fungal protein cerato-platanin, separately and in combination. Our results showed incompatibility between the ordinary ROS-mediated response to fungal attack and the acquired mechanisms of preventing oxidative stress in the tolerant population. A similar situation was also demonstrated by the sensitive population growing in the presence of copper but, in this case, with a lack of certain responses, such as callose production. In addition, in terms of the joint behaviour of emitted volatiles, multivariate statistics showed that not only did the populations respond differently to the presence of copper or biotic stress, but also that the biotic and abiotic stresses interacted in different ways in the two populations. Our results demonstrated that the same incompatibility of hyperaccumulators in ROS-mediated biotic stress signals also seemed to be exhibited by the excluder metallophyte, but without the advantage of being able to rely on the elemental defence for plant protection from natural enemies.
Najdeno v: osebi
Ključne besede: Biotic interactions Callose Heavy metals Oxidative stress VOCs
Objavljeno: 20.04.2020; Ogledov: 347; Prenosov: 0
.pdf Polno besedilo (6,63 MB)

Linking root traits to copper exclusion mechanisms in Silene paradoxa L. (Caryophyllaceae)
Ilaria Colzi, Sara Pignattelli, Elisabetta Giorni, Alessio Papini, Cristina Gonnelli, 2015, izvirni znanstveni članek

Opis: Copper is one of the most important pollutants in mine- contaminated soils. This study tests the response in a sensitive population vs a tolerant one of the model species Silene paradoxa in order to understand the general mechanisms of tolerance at the micromorphological and ultrastructural level. Two populations of Silene paradoxa were grown in hydroponics and exposed to different CuSO4 treatments. The roots were investigated with light, fluorescence and transmission electron microscope. Callose and lignin were spectrophotometrically determined. The tolerant population constitutively possessed a higher amount of mucilage and was able to reduce the length of the zone between the apex and the first lignified tracheids. Callose production decreased. It did not show remarkable copper-induced ultrastructural modifications, apart from the presence of precipitates in the tangential walls. The sensitive population showed huge nucleoli with a spongy periphery in the central cylinder together with the presence of electrondense granules in the mitochondria. Plastids were rarely observed and generally very electrondense and elongated. In the copper tolerant population of S. paradoxa some of the root traits concurring to generate metal-excluding roots were suggested to be mucilage and lignin production and the reduction of the subapical root zone.
Najdeno v: osebi
Ključne besede: Root, Copper exclusion, Lignin, Callose, Tolerance to copper, Silene paradoxa
Objavljeno: 20.04.2020; Ogledov: 327; Prenosov: 0
.pdf Polno besedilo (2,13 MB)

Copper tolerance strategies involving the root cell wall pectins in Silene paradoxa L.
Ilaria Colzi, Miluscia Arnetoli, Alessia Gallo, Saer Doumett, Massimo Del Bubba, Sara Pignattelli, Roberto Gabbrielli, Cristina Gonnelli, 2012, izvirni znanstveni članek

Opis: New insights were provided on the function of root cell wall pectin concentration and methylation degree in copper tolerance studying contrasting ecotypes of Silene paradoxa. A metallicolous copper tolerant population and a non-metallicolous sensitive population were grown in hydroponics and exposed to different CuSO4 treatments to evaluate copper accumulation in relation to pectin concentration and methylation degree of the root cell wall. In short-term exposure experiments the tolerant population decreased root cell wall pectin concentration and increased their methylation degree, while the sensitive population did not respond. Moreover, a positive correlation between root pectin concentration and metal accumulation in root apoplast and symplast was found. In addition, a negative correlation between pectin methylation degree and apoplastic copper concentration were found to be negatively correlated. In longterm exposure experiments, the sensitive population increased the concentration of pectins with the same methylation degree and consequently the ability of its root cell wall to bind the metal. The opposite phenomenon was shown by the tolerant population. Moreover, pectin methylation degree was higher in the tolerant population in respect to the sensitive one, possibly to limit metal binding to the root cell wall. Therefore, in the copper tolerant population of S. paradoxa the generation of metal-excluding root cell walls was suggested to be one of the factors concurring to guarantee a low apoplastic copper accumulation and probably also to limit symplastic copper uptake by the root cells.
Najdeno v: osebi
Ključne besede: Copper tolerance Cell wall Pectin Methylation Root
Objavljeno: 20.04.2020; Ogledov: 336; Prenosov: 0
.pdf Polno besedilo (4,80 MB)

Cadmium phytoextraction potential of different Alyssum species
Rita Barzanti, Ilaria Colzi, Miluscia Arnetoli, Alessia Gallo, Sara Pignattelli, Roberto Gabbrielli, Cristina Gonnelli, 2011, izvirni znanstveni članek

Opis: This work was planned for providing useful information about the possibility of using serpentine adapted plants for phytoextraction of cadmium, element scarcely represented in such metalliferous environment. To this aim, we investigated variation in cadmium tolerance, accumulation and translocation in three Alyssum plants with different phenotypes: Alyssum bertolonii, that is a serpentine endemic nickel hyper-accumulator, and two populations of Alyssum montanum, one adapted and one not adapted to serpentine soils. Plants were hydroponically cultivated in presence of increasing concentrations of CdSO(4) for two weeks. For the metal concentration used in the experiments, the three different Alyssum populations showed variation in cadmium tolerance, accumulation and content. The serpentine adapted population of A. montanum showed statistically higher cadmium tolerance and accumulation than A. bertolonii and the population of A. montanum not adapted to serpentine soil thus deserving to be investigated for phytoextraction purposes. Furthermore, as for the kinetic parameters of the cadmium uptake system, A. montanum serpentine population presented a low apparent K(m) value, suggesting a high affinity for this metal of its uptake system, whereas the V(max) values were not significantly different among the plants. Present data revealed metallicolous plants are also suitable for the phytoremediation of metals under-represented in the environment of their initial origin. Nonetheless, field trials on real contaminated soils are essential.
Najdeno v: osebi
Ključne besede: Alyssum, Cadmium, Tolerance, Accumulation, Phytoextraction
Objavljeno: 20.04.2020; Ogledov: 356; Prenosov: 0
.pdf Polno besedilo (4,09 MB)

Development of encapsulation techniques for the production and conservation of synthetic seeds in ornamental plants
Yelda Ozden-Tokatli, Anna De Carlo, Fusun Gumusel, Sara Pignattelli, Maurizio Lambardi, 2008, izvirni znanstveni članek

Opis: The synthetic seed ("synseed") technology, initially developed through the encapsulation of somatic embryos, is now available for the use with non-embryogenic in vitro-derived explants, such as buds and nodal segments. For ornamental plants, to date there are few reports dealing with the production and the conservation of synseeds. Hence, the present study was conducted to develop an efficient encapsulation protocol for apical and axillary buds from various ornamental shrubs, i.e., oleander (Nerium oleander L.), photinia (Photinia fraseri Dress.), and lilac (Syringa vulgaris L.). For encapsulation, apical and axillary buds were excised, directly immersed in a Na-alginate solution, and then released dropwise in 100 mM CaCl2 center dot 2H(2)O for bead hardening. With photinia, best results were achieved when the synseeds were prepared using 3% Na-alginate, beads hardened for 30 min and germinated on hormone-free or BA-containing gelled MS medium. Thus, up to 92% of synseeds germinated and converted to shoots in a period of 10-11 days. The synthetic seeds of lilac, containing apical buds, showed a shorter germination time when 10-30 g 1(-1) sucrose was included in their "artificial endosperm". Successful medium-term conservation was then achieved with the storage of synthetic seeds at 4 degrees C in the dark on gelled MS medium, where up to 75% (oleander) and and 9 1 % (photinia) synseeds still germinated after 2 or 3 months of cold storage, respectively. Moreover, promising results have been obtained with the cryopreservation of photinia apical buds by means of the technique of "encapsulation-dehydration".
Najdeno v: osebi
Ključne besede: conservation, cryopreservation, encapsulation, ornamentals, synthetic seeds
Objavljeno: 20.04.2020; Ogledov: 360; Prenosov: 0
.pdf Polno besedilo (3,94 MB)

Physiological responses of garden cress (L. sativum) to different types of microplastics
Sara Pignattelli, Andrea Broccoli, Monia Renzi, 2020, izvirni znanstveni članek

Opis: In this study, for the first time, acute and chronic toxicity caused by four different kinds of microplastics: polypropylene (PP), polyethylene (PE), polyvinylchloride (PVC), and a commercial mixture (PE + PVC) on Lepidium sativum were evaluated. Parameters considered were: i) biometric parameters (e.g. percentage inhibition of seed germination, plant height, leaf number and fresh biomass productions); and ii) oxidative stress (e.g. levels of hydrogen peroxide, glutathione, and ascorbic acid). On plants exposed to chronic stress chlorophylls, carotenoids, aminolaevulinic acid, and proline productions were, also, evaluated. PVC resulted the most toxic than other plastic materials tested. This study represents the first paper highlighting microplastics are able to produce oxidative burst in tested plants and could represent an important starting point for future researches on biochemical effects of microplastic in terrestrial environments such as agroecosystems.
Najdeno v: osebi
Ključne besede: Polypropylene Polyethylene Polyvinylchloride Plastic packaging Microplastics Plant exposure
Objavljeno: 24.04.2020; Ogledov: 360; Prenosov: 0
.pdf Polno besedilo (5,55 MB)

Silver nanoparticles enter the tree stem faster through leaves than through roots
Claudia Cocozza, Annalisa Perone, Cristiana Giordano, Maria Cristina Salvatici, Sara Pignattelli, Aida Raio, Marcus Schaub, Kruno Sever, John L. Innes, Roberto Tognetti, Paolo Cherubini, 2019, izvirni znanstveni članek

Opis: A major environmental pollution problem is the release into the atmosphere of particulate matter, including nanoparticles (NPs), which causes serious hazards to human and ecosystem health, particularly in urban areas. However, knowledge about the uptake, translocation and accumulation of NPs in plant tissues is almost completely lacking. The uptake of silver nanoparticles (Ag-NPs) and their transport and accumulation in the leaves, stems and roots of three different tree species, downy oak (Quercus pubescens Willd.), Scots pine (Pinus sylvestris L.) and black poplar (Populus nigra L.), were assessed. In the experiment, Ag- NPs were supplied separately to the leaves (via spraying, the foliar treatment) and roots (via watering, the root treatment) of the three species. Uptake, transport and accumulation of Ag were investigated through spectroscopy. The concentration of Ag in the stem was higher in the foliar than in the root treatment, and in poplar more than in oak and pine. Foliar treatment with Ag-NPs reduced aboveground biomass and stem length in poplars, but not in oaks or pines. Species-specific signals of oxidative stress were observed; foliar treatment of oak caused the accumulation of H2O2 in leaves, and both foliar and root treatments of poplar led to increased O2− in leaves. Ag-NPs affected leaf and root bacteria and fungi; in the case of leaves, foliar treatment reduced bacterial populations in oak and poplar and fungi populations in pine, and in the case of roots, root treatment reduced bacteria and increased fungi in poplar. Species-specific mechanisms of interaction, transport, allocation and storage of NPs in trees were found. We demonstrated definitively that NPs enter into the tree stem through leaves faster than through roots in all of the investigated tree species.
Najdeno v: osebi
Ključne besede: Ag-NPs, pathway of uptake, Pinus sylvestris L., Populus nigra L., Quercus pubescens Willd.
Objavljeno: 20.04.2020; Ogledov: 343; Prenosov: 0
.pdf Polno besedilo (971,60 KB)

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