1. Impact of microplastics on growth, photosynthesis and essential elements in Cucurbita pepo L.Ilaria Colzi, Luciana Renna, Elisabetta Bianchi, Maria Beatrice Castellani, Andrea Coppi, Sara Pignattelli, Stefano Loppi, Cristina Gonnelli, 2022, original scientific article Abstract: In this study, Cucurbita pepo L., one of the most cultivated, consumed and economically important crop worldwide, was used as model plant to test the toxic effects of the four most abundant microplastics identified in contaminated soils, i.e. polypropylene (PP), polyethylene (PE), polyvinylchloride (PVC), and polyethyleneterephthalate (PET). Cucurbita plants were grown in pots with increasing concentrations of the microplastics, then plant biometry, photosynthetic parameters and ionome of treated vs. untreated samples were compared to evaluate the toxicity of each plastic. All the pollutants impaired root and, especially, shoot growth. Specific and concentration-dependant effects of the different microplastics were found, including reduction in leaf size, chlorophyll content and photosynthetic efficiency, as well as changes in the micro- and macro-elemental profile. Among all the microplastics, PVC was identified as the most toxic and PE as the less toxic material. PVC decreased the dimensions of the leaf lamina, the values of the photosynthetic performance index and the plant iron concentration to a higher extent in respect to the other treatments. Microplastic toxicity exerted on the growth of C. pepo raises concerns about possible yield and economic loss, as well as for risks of a possible transfer into the food chain. Keywords: microplastic toxicity, leaf traits, chlorophyll fluorescence, ionome, zucchini Published in RUNG: 17.12.2021; Views: 2959; Downloads: 8 Link to full text This document has many files! More... |
2. Cadmium phytoextraction potential of different Alyssum speciesRita Barzanti, Ilaria Colzi, Miluscia Arnetoli, Alessia Gallo, Sara Pignattelli, Roberto Gabbrielli, Cristina Gonnelli, 2011, original scientific article Abstract: 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. Keywords: Alyssum, Cadmium, Tolerance, Accumulation, Phytoextraction Published in RUNG: 20.04.2020; Views: 3678; Downloads: 0 This document has many files! More... |
3. Exploring element accumulation patterns of a metal excluder plant naturally colonizing a highly contaminated soilSara Pignattelli, Ilaria Colzi, Lorenzo Cecchi, Miluscia Arnetoli, Roberto Monnanni, Roberto Gabbrielli, Cristina Gonnelli, 2012, original scientific article Abstract: This work investigates the element distribution in Silene paradoxa growing on the mine dump of Fenice Capanne (Tuscany, Italy). The accumulation of As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn in root apoplast and symplast and in shoot was assessed and compared to the levels of the same metals in the respective rizosphere soils, analyzing both the total and the phytoavailable fractions.
Levels of As, Cu, Fe, Pb and Zn, were above toxicity thresholds in both soil and shoot samples. Inter- and intra-element correlations were analyzed in plant and soil using different statistical methods. Soil total and phytoavailable metal concentration were shown not to be dominant in determining metal accumulation by the plant, since no significant positive correlation was found between metal concentration in soils and plants. Moreover, results indicated that S. paradoxa was able to cope with the studied multi-metal contaminated soil excluding the elements from its tissues and preferentially accumulating them into the root compartment, thus suggesting this species as possible good candidate for phytostabilization purposes. Keywords: Metals, Mine dump, Phytostabilization, Silene paradoxa, Compositional data analysis Published in RUNG: 20.04.2020; Views: 3676; Downloads: 0 This document has many files! More... |
4. 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, original scientific article Abstract: 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. Keywords: Copper tolerance
Cell wall
Pectin
Methylation
Root Published in RUNG: 20.04.2020; Views: 3671; Downloads: 0 This document has many files! More... |
5. A multielement analysis of Cu induced changes in the mineral profilesof Cu sensitive and tolerant populations of Silene paradoxa L.Sara Pignattelli, Ilaria Colzi, Antonella Buccianti, Ilenia Cattani, Gian Maria Beone, Henk Schat, Cristina Gonnelli, 2013, original scientific article Abstract: tThis work investigates the Cu induced changes in element profiles in contrasting ecotypes of Silene para-doxa L. A metallicolous copper tolerant population and a non-metallicolous sensitive population weregrown in hydroponics and exposed to different CuSO4treatments. Shoot and root concentrations of Ca,Cu, Fe, K, Mg, Mn, Mo, Na, P, S and Zn were evaluated through ICP-OES.Results indicated that increasing the environmental Cu concentration had a population dependenteffect on element profiles, shoot-to-root ratios and correlations among the elements. Generally, in thetolerant population Cu treatment induced a higher element accumulation in roots and had minimaleffects on the shoot element profile, thus resulting in a progressively decreasing shoot-to-root ratio foreach element. In the sensitive population element concentrations in root and shoot were much moreaffected and without a consistent trend. Copper treatment also affected the correlations between theelements, both in roots and shoots of the two populations, but more so in the sensitive population thanin the tolerant one. Thus, Cu exposure strongly disturbed element homeostasis in the sensitive population,but barely or not in the tolerant one, probably mainly due to a higher capacity to maintain proper rootfunctioning under Cu exposure in the latter. Differences in element profiles were also observed in theabsence of toxic Cu exposure. These differences may reflect divergent population-specific adaptations todifferential nutrient availability levels prevailing in the populations’ natural environments. There is noevidence of inherent side-effects of the Cu tolerance mechanism operating in the tolerant population. Keywords: Mineral profile, Copper tolerance, Silene paradoxa, Compositional data analysis Published in RUNG: 20.04.2020; Views: 3714; Downloads: 0 This document has many files! More... |
6. Linking root traits to copper exclusion mechanisms in Silene paradoxa L. (Caryophyllaceae)Ilaria Colzi, Sara Pignattelli, Elisabetta Giorni, Alessio Papini, Cristina Gonnelli, 2015, original scientific article Abstract: 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. Keywords: Root, Copper exclusion, Lignin, Callose, Tolerance to copper, Silene paradoxa Published in RUNG: 20.04.2020; Views: 3706; Downloads: 0 This document has many files! More... |
7. Under fungal attack on a metalliferous soil: ROS or not ROS? Insights from Silene paradoxa L. growing under copper stressCosimo Taiti, Elisabetta Giorni, Ilaria Colzi, Sara Pignattelli, Nadia Bazihizina, Antonella Buccianti, Simone Luti, Luigia Pazzagli, Stefano Mancuso, Cristina Gonnelli, 2016, original scientific article Abstract: 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. Keywords: Biotic interactions
Callose
Heavy metals
Oxidative stress
VOCs Published in RUNG: 20.04.2020; Views: 4479; Downloads: 0 This document has many files! More... |
8. The multi-purpose role of hairiness in the lichens of coastal environments: Insights from Seirophora villosa (Ach.) FrödénElisabetta Bianchi, Renato Benesperi, Ilaria Colzi, Andrea Coppi, Lorenzo Lazzaro, Luca Paoli, Alessio Papini, Sara Pignattelli, Corrado Tani, Pamela Vignolini, Cristina Gonnelli, 2019, original scientific article Abstract: 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. Keywords: Antioxidant activity
Chlorophyll a fluorescence
Juniperus shrublands
Hair
MDA
Salt stress Published in RUNG: 20.04.2020; Views: 3597; Downloads: 0 This document has many files! More... |