Papers by Giovanna Visioli
Microorganisms, Jun 28, 2021
Soil is one of the key elements for supporting life on Earth. It delivers multiple ecosystem serv... more Soil is one of the key elements for supporting life on Earth. It delivers multiple ecosystem services, which are provided by soil processes and functions performed by soil biodiversity. In particular, soil microbiome is one of the fundamental components in the sustainment of plant biomass production and plant health. Both targeted and untargeted management of soil microbial communities appear to be promising in the sustainable improvement of food crop yield, its nutritional quality and safety. -Omics approaches, which allow the assessment of microbial phylogenetic diversity and functional information, have increasingly been used in recent years to study changes in soil microbial diversity caused by agronomic practices and environmental factors. The application of these high-throughput technologies to the study of soil microbial diversity, plant health and the quality of derived raw materials will help strengthen the link between soil well-being, food quality, food safety and human health.
Plants
Plants are sessile organisms that must adapt to environmental conditions, such as soil characteri... more Plants are sessile organisms that must adapt to environmental conditions, such as soil characteristics, by adjusting their development during their entire life cycle. In case of low-distance seed dispersal, the new generations are challenged with the same abiotic stress encountered by the parents. Epigenetic modification is an effective option that allows plants to face an environmental constraint and to share the same adaptative strategy with their progeny through transgenerational inheritance. This is the topic of the presented review that reports the scientific progress, up to date, gained in unravelling the epigenetic response of plants to soil contamination by heavy metals and metalloids, collectively known as potentially toxic elements. The effect of the microbial community inhabiting the rhizosphere is also considered, as the evidence of a transgenerational transfer of the epigenetic status that contributes to the activation in plants of response mechanisms to soil pollution.
Environmental Science and Pollution Research, Nov 10, 2022
In this study, we assess the DNA damage occurring in response to cadmium (Cd) in the Cd hyperaccu... more In this study, we assess the DNA damage occurring in response to cadmium (Cd) in the Cd hyperaccumulator Noccaea caerulescens Ganges (GA) vs the non-accumulator and close-relative species Arabidopsis thaliana. At this purpose, the alkaline comet assay was utilized to evaluate the Cd-induced variations in nucleoids and the methy-sens comet assay, and semiquantitative real-time (qRT)-PCR were also performed to associate nucleus variations to possible DNA modifications. Cadmium induced high DNA damages in nuclei of A. thaliana while only a small increase in DNA migration was observed in N. caerulescens GA. In addition, in N. caerulescens GA, CpG DNA methylation increase upon Cd when compared to control condition, along with an increase in the expression of MET1 gene, coding for the DNA-methyltransferase. N. caerulescens GA does not show any oxidative stress under Cd treatment, while A. thaliana Cd-treated plants showed an upregulation of transcripts of the respiratory burst oxidase, accumulation of reactive oxygen species, and enhanced superoxide dismutase activity. These data suggest that epigenetic modifications occur in the N. caerulescens GA exposed to Cd to preserve genome integrity, contributing to Cd tolerance.
The bacterial and archaeal communities of two biogas producing plants (P1 and P2), associated wit... more The bacterial and archaeal communities of two biogas producing plants (P1 and P2), associated with a 999 kW cogeneration unit, both located in North Italy, were analyzed at start up and fully operating phases, by means of various molecular approaches: i) Automated Ribosomal Intergenic Spacer Analysis; ii) cloning and sequencing of PCR amplicons of archaeal genes 16Srrna and mcrA; iii) 16S rDNA high throughput next generation sequencing. P1 and P2 use the same technology and both were fed with cattle manure and corn silage. During the study of P1 also the post digestor (fed with pig manure) was analyzed. The aim of this research was to characterize the bacterial and archaeal community in two very similar plants to profile the core microbiome. The results of this analysis highlighted that the two plants (producing comparable quantities of volatile fatty acids, biogas, and energy) differed in anerobic microbiota (Bacteria and Archaea). Notably the methanogenic community of P1 was domin...
International Journal of Molecular Sciences, 2021
Metalliferous soils are characterized by a high content of metal compounds that can hamper plant ... more Metalliferous soils are characterized by a high content of metal compounds that can hamper plant growth. The pseudometallophyte Noccaea caerulescens is able to grow on metalliferous substrates by implementing both tolerance and accumulation of usually toxic metal ions. Expression of particular transmembrane transporter proteins (e.g., members of the ZIP and NRAMP families) leads to metal tolerance and accumulation, and its comparison between hyperaccumulator N. caerulescens with non-accumulator relatives Arabidopsis thaliana and Thlaspi arvense has deepened our knowledge on mechanisms adopted by plants to survive in metalliferous soils. In this work, two transporters, ZNT1 and NRAMP4, expressed in a serpentinic population of N. caerulescens identified on the Monte Prinzera (Italy) are considered, and their expression has been induced in yeast and in A. thaliana. In the latter, single transgenic lines were crossed to test the effect of the combined over-expression of the two transpor...
Microorganisms, 2021
Soil is one of the key elements for supporting life on Earth. It delivers multiple ecosystem serv... more Soil is one of the key elements for supporting life on Earth. It delivers multiple ecosystem services, which are provided by soil processes and functions performed by soil biodiversity. In particular, soil microbiome is one of the fundamental components in the sustainment of plant biomass production and plant health. Both targeted and untargeted management of soil microbial communities appear to be promising in the sustainable improvement of food crop yield, its nutritional quality and safety. –Omics approaches, which allow the assessment of microbial phylogenetic diversity and functional information, have increasingly been used in recent years to study changes in soil microbial diversity caused by agronomic practices and environmental factors. The application of these high-throughput technologies to the study of soil microbial diversity, plant health and the quality of derived raw materials will help strengthen the link between soil well-being, food quality, food safety and human h...
Applied Soil Ecology, 2020
Biostimulants are organic substances that can be applied to leaves, seeds or soil for enhancing p... more Biostimulants are organic substances that can be applied to leaves, seeds or soil for enhancing plant growth and optimize productivity also in condition of stress-induced limitations. In this work, we combined mass spectrometry-based soil metaproteomics with a 18 multiplex enzymatic assay to investigate the effects of two different biostimulants (B1 and B2) on the rhizosphere of four-leaf stage maize plants. The rhizosphere of biostimulanttreated samples resulted in an enhancement of enzymatic activity related to phosphorus and glucose processes, highly induced in B1 sample. More than 700 unique proteins for each sample, identified by liquid chromatography-high resolution mass spectrometry, revealed an increase, especially for B2, in the representation of Gene Ontology biological process categories related to carbohydrate, organic substance and phosphorus metabolism, broadly matching the enzymatic activities. Furthermore, KEGG database analysis showed that proteins involved in antibiotic resistance were more abundant in both biostimulant-treated samples. The biostimulants therefore increased at a different extent the activity of the bacterial community, in particular species beneficial to plant growth, as Bradyrhizobium japonicum, Hyalangium minutum, Stenotrophomonas rhizophila, Variovorax paradoxus and Paenibacillus macerans, without changing the composition of the microbiota. Our investigation highlighted for the first time that biostimulants modified directly and positively the bacterial activity of the rhizosphere, suggesting that they would be ideal for organic and sustainable farming.
International Journal of Molecular Sciences, 2019
Mineral nutrition of plants greatly depends on both environmental conditions, particularly of soi... more Mineral nutrition of plants greatly depends on both environmental conditions, particularly of soils, and the genetic background of the plant itself. Being sessile, plants adopted a range of strategies for sensing and responding to nutrient availability to optimize development and growth, as well as to protect their metabolisms from heavy metal toxicity. Such mechanisms, together with the soil environment, meaning the soil microorganisms and their interaction with plant roots, have been extensively studied with the goal of exploiting them to reclaim polluted lands; this approach, defined phytoremediation, will be the subject of this review. The main aspects and innovations in this field are considered, in particular with respect to the selection of efficient plant genotypes, the application of improved cultural strategies, and the symbiotic interaction with soil microorganisms, to manage heavy metal polluted soils.
Applied Microbiology and Biotechnology, 2018
β-propeller phytase-like sequences (BPP-like sequences) are widespread in the microbial world and... more β-propeller phytase-like sequences (BPP-like sequences) are widespread in the microbial world and have been found in the sequenced genomes of aquatic, soil, and plant bacteria. Exploring NCBI microbial genome database for putative genes encoding phytase, a BPP-like sequence from Sphingomonas wittichii RW-1 (Sequence ID: CP000699.1), known for its capacity of degrading polychlorinated dibenzo-p-dioxins and dibenzofurans, was recognized. The putative phytase gene (phySw) was amplified with specific primers, cloned, and overexpressed in Escherichia coli and the catalytic properties of the recombinant PhySw protein were analyzed. The results show that phySw encodes an enzyme with the properties of β-propeller phytases: it requires the presence of Ca 2+ ions, it is optimally active at 55 °C, and it has a pH optimum of 6.0 with good activity in the range 6.0-8.0. Furthermore, the enzyme exhibits a good thermostability, recovering 68% of its original activity after treatment at 80 °C for 10 min, and shows a good substrate specificity for phytic acid. These properties render this enzyme a candidate as an animal feed additive (e.g., for aquaculture industry). The isolation of phytases from a hydrocarbon-utilizing microorganism also opens new scenarios for their possible application in combating oil pollution.
Environmental and Molecular Mutagenesis, 2018
The Ni hyperaccumulator Noccaea caerulescens has adapted to live in a naturally stressed environm... more The Ni hyperaccumulator Noccaea caerulescens has adapted to live in a naturally stressed environment, evolving a complex pattern of traits to cope with adverse conditions. Evidence is accumulating regarding the important role of epigenetic modifications in regulating plant responses to stress. In this study, we present data from the natural “open‐field” adaptation of the Ni hyperaccumulator N. caerulescens to serpentine soil and provide the first evidence of the involvement of epigenetic changes in response to the high Ni content present in plant leaves. The alkaline comet assay revealed the integrity of the nuclei of leaf cells of N. caerulescens grown in a Ni‐rich environment, while in the non‐tolerant Arabidopsis thaliana exposed to Ni, the nuclei were severely damaged. DNA of N. caerulescens plants grown in situ were considerably hyper‐methylated compared to A. thaliana plants exposed to Ni. In addition, qRT‐PCR revealed that N. caerulescens MET1, DRM2, and HDA8 genes involved i...
The New phytologist, 2017
In the hyperaccumulator Arabidopsis halleri, the zinc (Zn) vacuolar transporter MTP1 is a key com... more In the hyperaccumulator Arabidopsis halleri, the zinc (Zn) vacuolar transporter MTP1 is a key component of hypertolerance. Because protein sequences and functions are highly conserved between A. halleri and Arabidopsis thaliana, Zn tolerance in A. halleri may reflect the constitutively higher MTP1 expression compared with A. thaliana, based on copy number expansion and different cis regulation. Three MTP1 promoters were characterized in A. halleri ecotype I16. The comparison with the A. thaliana MTP1 promoter revealed different expression profiles correlated with specific cis-acting regulatory elements. The MTP1 5' untranslated region, highly conserved among A. thaliana, Arabidopsis lyrata and A. halleri, contains a dimer of MYB-binding motifs in the A. halleri promoters absent in the A. thaliana and A. lyrata sequences. Site-directed mutagenesis of these motifs revealed their role for expression in trichomes. A. thaliana mtp1 transgenic lines expressing AtMTP1 controlled by the...
Food Analytical Methods, 2015
ABSTRACT Durum wheat (Triticum turgidum L.) flour is instrumental for the production of pasta wor... more ABSTRACT Durum wheat (Triticum turgidum L.) flour is instrumental for the production of pasta worldwide. The quality of this food rests on flour processing and on its protein content and composition. Gluten proteins as high and low-molecular weight glutenins (GS) are important to predict the flour technological property in pasta making. Different methods were compared to separate, identify and quantify GS in flours from two wheat cultivars. Sodium dodecyl sulphate-polyacrilamide gel electrophoresis (SDS-PAGE) gave in a fast way information about the GS assets. Two-dimensional gel electrophoresis (2D-GE) allowed for the highest resolution in detecting and quantifying single GS, subsequently identified by liquid chromatography-electrospray ionization mass spectrometry (LC-ESI-MS/MS). Reversed-phase high-performance liquid chromatography (RP-HPLC) is a non-gel alternative system for separation and quantification of single GS that when combined with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/MS) gave information about their exact masses. This method gives also quantitative indications of each individual GS. Different GS patterns and contents were detected in the flour of the two cultivars, underlining the importance of these analytical methods before determining the best flour processing procedure in pasta making. The different methods were evaluated with a modular approach consisting of a grid of different parameters and a non-linear score within each module.
Micron, 2015
microscopy (ESEM) X-ray microanalysis (EDS) Nickel Ni hyperaccumulator Noccaea caerulescens Hydra... more microscopy (ESEM) X-ray microanalysis (EDS) Nickel Ni hyperaccumulator Noccaea caerulescens Hydrated samples In vivo analysis a b s t r a c t Environmental scanning electron microscopy (ESEM) permits to analyze samples in their native-hydrated state, allowing a broad spectrum of biological applications. In this study, ESEM equipped with energy dispersive X-ray spectrometer (EDS) was used as a fast method to analyze tissue morphology and to investigate metal distribution in the Ni hyperaccumulator Noccaea caerulescens, an established model to study the adaptation of plants to metalliferous soils. The low vacuum and wet mode operative conditions required the proper choice of experimental parameters both for morphological and compositional characterization of plant tissues. The calibration strategy for semi-quantitative analysis involved the use of Ni fortified agar as standard and signal normalization respect to endogenous carbon, chosen as internal standard. The obtained results are in accordance with present literature, showing a preferential Ni distribution in the epidermal cells respect to near the stomata for leaves and in the cotyledon epidermidis respect to cotyledon parenchyma area for seeds. Thanks to the absence of any time consuming sample treatment steps, ESEM-EDS technique can be proposed as valid strategy for in vivo high-throughput analysis of plant tissues and for a rapid screening and identification of other hyperaccumulator plants in a selected contaminated area.
Potato Research, 2000
We have evaluated the effect that the silencing of two genes specifically expressed in conditions... more We have evaluated the effect that the silencing of two genes specifically expressed in conditions of dormancy (A2-1) and sprouting (GI-1) had on tuber dormancy. For this purpose potato plants (Solanum taberosum L. cv. D6sir6e) were transformed with the antisense of the genes GI-1 and A2-1 under the control of constitutive 35S CaMV promoter. A first generation of transgenic plants was propagated from axenic stem cuttings and a second generation by tuber planting. The plants obtained were analyzed for the length of dormancy, plant morphology and agronomic characteristics. Statistical analysis of dormancy in lines obtained from the original transformants for the antisense of GI-1 gene showed a significant increase in length as compared with different types of control plants, with few effects on plant vegetative habit and tuber production. In contrast, results obtained on A2-1 antisense transformed plants did not reveal any significant change on the length of dormancy. Here we report small-scale field trials performed with the aim to select and regenerate commercially exploitable potato plants with a stable transgene-dependent phenotype, affecting the length of dormancy.
Potato Research, 2000
Two cDNAs, corresponding to genes differentially regulated during dormancy and sprouting in potat... more Two cDNAs, corresponding to genes differentially regulated during dormancy and sprouting in potato tubers, cultivar D6sir6e, were isolated: i) GI-1 corresponded to a gene that was turned off during dormancy and turned on during early phases of sprouting: ii) A2-1 corresponded to a gene activated during dormancy and strongly repressed during the transition from dormancy to sprouting. When induced, both genes were expressed at low level. Full-length cDNAs and genomic clones were isolated and characterized. G 1-1 was a short gene, 452 bp long, containing an intronless open reading frame, coding for a putative protein of 64 aminoacids. Sequence analysis showed that G 1-I was homologous to an expressed sequence tag (EST) of A rabidopsis thaliana. A2-1 full-length cDNA was 1577 bp long and contained an open reading frame coding for a putative protein of 383 aminoacids, which contained a Walker box binding domain, common to a multifunctional family of intracellular ATPases.
Plant Science, 2007
To determine the role of genes in plant development, we have analysed the expression of G1-1, a g... more To determine the role of genes in plant development, we have analysed the expression of G1-1, a gene isolated in potato tuber and of its tomato homologues LeG1-1 and LeG1-2. Expression of G1-1 in tuber increased in buds during the first stages of sprouting, whereas almost no transcript was found in the parenchyma. The highest levels of expression were detectable in sprouts and in developing sink leaves. In situ hybridization on potato tissues showed that the G1-1 transcript was mainly localized in shoot apical meristems, suggesting that the expression of this gene was correlated to meristem activity. LeG1-1 and LeG1-2 expression, measured at different stages of tomato seed germination showed its maximum after the primordial roots emerged from the teguments. High levels of transcript were found both in roots and hypocotyls of the seedlings. Indeed LeG1-1 and LeG1-2 transcript levels were low in meristematic structures formed in the in vitro cultured tomato hypocotyls and in explants of cotyledons. All these results suggest that G1-1 and its homologues, LeG1-1 and LeG1-2, may be involved in the maintenance of the sink function of potato tuber and tomato seed. In these organs, they are also responsible for activation and growth of pre-existing meristems, but not in their de novo formation.
Journal of Chromatography B, 2006
Two-dimensional liquid chromatography based on a high-performance chromatofocusing in the first d... more Two-dimensional liquid chromatography based on a high-performance chromatofocusing in the first dimension followed by high-resolution reversed-phase chromatography in the second dimension can be used as a complementary approach to protein separation with two-dimensional gel electrophoresis. In this work, Arabidopsis thaliana proteins obtained from different tissue extracts were resolved by using a new automated system, ProteomeLab PF 2D commercialized by Beckman Coulter (Fullerton, CA, USA). In particular, protein patterns obtained after two different extraction procedures (MgSO 4 and urea buffer) were compared. Reproducibility of the protein patterns was also confirmed in different injections of the same sample and in the comparative analyses of some proteins by MALDI-TOF/MS. Computer analysis of the chromatograms revealed that with this two-dimensional liquid phase technique, hundreds of "virtual bands" can be identified and compared in crude plant protein lysates.
Food Control, 2010
Globalization of food trade requires the development of integrated approaches, such as traceabili... more Globalization of food trade requires the development of integrated approaches, such as traceability of origin, quality and authenticity, to ensure food safety and consumers satisfaction. In this study, different genomic DNA extraction procedures were evaluated for their applicability to internal traceability of different products in the tomato food chain. Quality, quantity and amplificability by SSR markers of extracted DNA tallied the methods performances; times and costs were considered too. The results were processed with ''fuzzy-logic" approach. ''Wizard" (Promega) scored the best performance in methods final ranking. This work demonstrated the value of genomic methodologies for internal traceability of tomato-derived goods.
Environmental Science & Technology, 2011
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Papers by Giovanna Visioli