Publications by authors named "Marcello S Lenucci"

20 Publications

  • Page 1 of 1

Ride to cell wall: Arabidopsis XTH11, XTH29 and XTH33 exhibit different secretion pathways and responses to heat and drought stress.

Plant J 2021 May 1. Epub 2021 May 1.

Dipartimento di Scienze e Tecnologie Biologiche e Ambientali, Università del Salento, Lecce, 73100, Italy.

The xyloglucan endotransglucosylase/hydrolases (XTHs) are enzymes involved in cell wall assembly and growth regulation, cleaving and re-joining hemicellulose chains in the xyloglucan-cellulose network. Here, in a homologous system, we compare the secretion patterns of XTH11, XTH33 and XTH29, three members of the Arabidopsis thaliana XTH family, selected for the presence (XTH11 and XTH33) or absence (XTH29) of a signal peptide, and the presence of a transmembrane domain (XTH33). We show that XTH11 and XTH33 reached, respectively, the cell wall and plasma membrane through a conventional protein secretion (CPS) pathway, whereas XTH29 moves towards the apoplast following an unconventional protein secretion (UPS) mediated by exocyst-positive organelles (EXPOs). All XTHs share a common C-terminal functional domain (XET-C) that, for XTH29 and a restricted number of other XTHs (27, 28 and 30), continues with an extraterminal region (ETR) of 45 amino acids. We suggest that this region is necessary for the correct cell wall targeting of XTH29, as the ETR-truncated protein never reaches its final destination and is not recruited by EXPOs. Furthermore, quantitative real-time polymerase chain reaction analyses performed on 4-week-old Arabidopsis seedlings exposed to drought and heat stress suggest a different involvement of the three XTHs in cell wall remodeling under abiotic stress, evidencing stress-, organ- and time-dependent variations in the expression levels. Significantly, XTH29, codifying the only XTH that follows a UPS pathway, is highly upregulated with respect to XTH11 and XTH33, which code for CPS-secreted proteins.
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http://dx.doi.org/10.1111/tpj.15301DOI Listing
May 2021

Bioactive composition and sensory evaluation of innovative spaghetti supplemented with free or α-cyclodextrin chlatrated pumpkin oil extracted by supercritical CO.

Food Chem 2019 Oct 8;294:112-122. Epub 2019 May 8.

Istituto di Scienze delle Produzioni Alimentari (ISPA), Consiglio Nazionale delle Ricerche (CNR), Lecce, Italy. Electronic address:

The feasibility of producing durum wheat pasta enriched with a lipophilic phytocomplex, extracted using supercritical carbon dioxide (SC-CO), from ripe pumpkin, as free oil or as ready-to-mix oil/α-cyclodextrins (α-CDs) powder, was explored. Four types of pasta were prepared: (i) control spaghetti (S-CTRL); (ii) spaghetti supplemented with α-CDs (S-α-CD); (iii) spaghetti supplemented with pumpkin oil (S-Oil) and (iv) spaghetti supplemented with the pumpkin oil/α-CD powder (S-Oil/α-CD). The chemical, antioxidant, textural and sensory attributes of the different pasta were evaluated and compared. S-Oil and S-Oil/α-CD spaghetti were significantly enriched with phytosterols, squalene, carotenoids, tocochromanols and unsaturated fatty acids. Spaghetti containing α-CDs were slightly improved in terms of fiber content. Oil chlatration increased the stability of some bioactives during pasta production and ameliorated poor textural and sensory characteristics of the cooked spaghetti compared with S-Oil sample. S-Oil/α-CD spaghetti might be accepted by customers, if the potential health benefits were also explained.
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http://dx.doi.org/10.1016/j.foodchem.2019.05.032DOI Listing
October 2019

Population genomics reveals evolution and variation of Saccharomyces cerevisiae in the human and insects gut.

Environ Microbiol 2019 01 21;21(1):50-71. Epub 2018 Nov 21.

Department of Biology, University of Florence, Florence, Italy.

The quest to discover the variety of ecological niches inhabited by Saccharomyces cerevisiae has led to research in areas as diverse as wineries, oak trees and insect guts. The discovery of fungal communities in the human gastrointestinal tract suggested the host's gut as a potential reservoir for yeast adaptation. Here, we report the existence of yeast populations associated with the human gut (HG) that differ from those isolated from other human body sites. Phylogenetic analysis on 12 microsatellite loci and 1715 combined CDSs from whole-genome sequencing revealed three subclusters of HG strains with further evidence of clonal colonization within the host's gut. The presence of such subclusters was supported by other genomic features, such as copy number variation, absence/introgressions of CDSs and relative polymorphism frequency. Functional analysis of CDSs specific of the different subclusters suggested possible alterations in cell wall composition and sporulation features. The phenotypic analysis combined with immunological profiling of these strains further showed that sporulation was related with strain-specific genomic characteristics in the immune recognition pattern. We conclude that both genetic and environmental factors involved in cell wall remodelling and sporulation are the main drivers of adaptation in S. cerevisiae populations in the human gut.
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http://dx.doi.org/10.1111/1462-2920.14422DOI Listing
January 2019

Different effectiveness of two pastas supplemented with either lipophilic or hydrophilic/phenolic antioxidants in affecting serum as evaluated by the novel Antioxidant/Oxidant Balance approach.

Food Chem 2017 Apr 13;221:278-288. Epub 2016 Oct 13.

Dipartimento di Scienze Agrarie, degli Alimenti e dell'Ambiente, Università degli Studi di Foggia, Via Napoli, 25, 71122 Foggia, Italy. Electronic address:

Effectiveness in improving serum antioxidant status of two functional pastas was evaluated by the novel Antioxidant/Oxidant Balance (AOB) parameter, calculated as Antioxidant Capacity (AC)/Peroxide Level ratio, assessed here for the first time. In particular, Bran Oleoresin (BO) and Bran Water (BW) pastas, enriched respectively with either lipophilic (tocochromanols, carotenoids) or hydrophilic/phenolic antioxidants extracted from durum wheat bran, were studied. Notably, BO pasta was able to improve significantly (+65%) serum AOB during four hours after intake similarly to Lisosan G, a wheat antioxidant-rich dietary supplement. Contrarily, BW pasta had oxidative effect on serum so as conventional pasta and glucose, thus suggesting greater effectiveness of lipophilic than hydrophilic/phenolic antioxidants under our experimental conditions. Interestingly, no clear differences between the two pastas were observed, when AC measurements of either serum after pasta intake or pasta extracts by in vitro assays were considered, thus strengthening effectiveness and reliability of AOB approach.
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http://dx.doi.org/10.1016/j.foodchem.2016.10.050DOI Listing
April 2017

Drought and Heat Differentially Affect XTH Expression and XET Activity and Action in 3-Day-Old Seedlings of Durum Wheat Cultivars with Different Stress Susceptibility.

Front Plant Sci 2016 10;7:1686. Epub 2016 Nov 10.

Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Università del Salento Lecce, Italy.

Heat and drought stress have emerged as major constraints for durum wheat production. In the Mediterranean area, their negative effect on crop productivity is expected to be exacerbated by the occurring climate change. Xyloglucan endotransglucosylase/hydrolases (XTHs) are chief enzymes in cell wall remodeling, whose relevance in cell expansion and morphogenesis suggests a central role in stress responses. In this work the potential role of XTHs in abiotic stress tolerance was investigated in durum wheat. The separate effects of dehydration and heat exposure on XTH expression and its endotransglucosylase (XET) activity and action have been monitored, up to 24 h, in the apical and sub-apical root regions and shoots excised from 3-day-old seedlings of durum wheat cultivars differing in stress susceptibility/tolerance. Dehydration and heat stress differentially influence the XTH expression profiles and the activity and action of XET in the wheat seedlings, depending on the degree of susceptibility/tolerance of the cultivars, the organ, the topological region of the root and, within the root, on the gradient of cell differentiation. The root apical region was the zone mainly affected by both treatments in all assayed cultivars, while no change in XET activity was observed at shoot level, irrespective of susceptibility/tolerance, confirming the pivotal role of the root in stress perception, signaling, and response. Conflicting effects were observed depending on stress type: dehydration evoked an overall increase, at least in the apical region of the root, of XET activity and action, while a significant inhibition was caused by heat treatment in most cultivars. The data suggest that differential changes in XET action in defined portions of the root of young durum wheat seedlings may have a role as a response to drought and heat stress, thus contributing to seedling survival and crop establishment. A thorough understanding of the mechanisms underlying these variations could represent the theoretical basis for implementing breeding strategies to develop new highly productive hybrids adapted to future climate scenarios.
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http://dx.doi.org/10.3389/fpls.2016.01686DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5102909PMC
November 2016

Serum antioxidant capacity and peroxide level of seven healthy subjects after consumption of different foods.

Data Brief 2016 Dec 4;9:818-822. Epub 2016 Nov 4.

Dipartimento di Scienze Agrarie, degli Alimenti e dell Ambiente, Università degli Studi di Foggia, Via Napoli, 25, 71122 Foggia, Italy.

This article reports experimental data related to the research article entitled "Different effectiveness of two pastas supplemented with either lipophilic or hydrophilic/phenolic antioxidants in affecting serum as evaluated by the novel Antioxidant/Oxidant Balance approach" (M.N. Laus, M. Soccio, M. Alfarano, A. Pasqualone, M.S. Lenucci, G. Di Miceli, D. Pastore, 2016) [1]. Antioxidant status of blood serum of seven healthy subjects was evaluated during four hours after consumption of two functional pastas, supplemented with either bran oleoresin or bran water extract obtained from durum wheat. For comparison, the effect of a non-supplemented reference pasta was also evaluated, as well as the effects of glucose, of the wheat grain dietary supplement Lisosan G, and of the reference pasta consumed together with Lisosan G. Serum antioxidant status was evaluated by measuring both the serum antioxidant capacity, using LOX-FL, ORAC and TEAC methods, and the serum oxidant status, assessed as peroxide level.
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http://dx.doi.org/10.1016/j.dib.2016.10.028DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5107679PMC
December 2016

Fungal Chitin Induces Trained Immunity in Human Monocytes during Cross-talk of the Host with Saccharomyces cerevisiae.

J Biol Chem 2016 Apr 17;291(15):7961-72. Epub 2016 Feb 17.

From the Research and Innovation Centre, Fondazione Edmund Mach, 38010 San Michele all'Adige TN, Italy, the Institute of Biometeorology, National Research Council, 50145 Florence, Italy, the Department of Biology, University of Florence, 50019 Sesto Fiorentino FI, Italy

The immune system is essential to maintain the mutualistic homeostatic interaction between the host and its micro- and mycobiota. Living as a commensal,Saccharomyces cerevisiaecould potentially shape the immune response in a significant way. We observed thatS. cerevisiaecells induce trained immunity in monocytes in a strain-dependent manner through enhanced TNFα and IL-6 production upon secondary stimulation with TLR ligands, as well as bacterial and fungal commensals. Differential chitin content accounts for the differences in training properties observed among strains, driving induction of trained immunity by increasing cytokine production and direct antimicrobial activity bothin vitroandin vivo These chitin-induced protective properties are intimately associated with its internalization, identifying a critical role of phagosome acidification to facilitate microbial digestion. This study reveals how commensal and passenger microorganisms could be important in promoting health and preventing mucosal diseases by modulating host defense toward pathogens and thus influencing the host microbiota-immune system interactions.
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http://dx.doi.org/10.1074/jbc.M115.699645DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4825003PMC
April 2016

Molecular dissection of Phaseolus vulgaris polygalacturonase-inhibiting protein 2 reveals the presence of hold/release domains affecting protein trafficking toward the cell wall.

Front Plant Sci 2015 26;6:660. Epub 2015 Aug 26.

Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Università del Salento Lecce, Italy.

The plant endomembrane system is massively involved in the synthesis, transport and secretion of cell wall polysaccharides and proteins; however, the molecular mechanisms underlying trafficking toward the apoplast are largely unknown. Besides constitutive, the existence of a regulated secretory pathway has been proposed. A polygalacturonase inhibitor protein (PGIP2), known to move as soluble cargo and reach the cell wall through a mechanism distinguishable from default, was dissected in its main functional domains (A, B, C, D), and C sub-fragments (C1-10), to identify signals essential for its regulated targeting. The secretion patterns of the fluorescent chimeras obtained by fusing different PGIP2 domains to the green fluorescent protein (GFP) were analyzed. PGIP2 N-terminal and leucine-rich repeat domains (B and C, respectively) seem to operate as holding/releasing signals, respectively, during PGIP2 transit through the Golgi. The B domain slows down PGIP2 secretion by transiently interacting with Golgi membranes. Its depletion leads, in fact, to the secretion via default (Sp2-susceptible) of the ACD-GFP chimera faster than PGIP2. Depending on its length (at least the first 5 leucine-rich repeats are required), the C domain modulates B interaction with Golgi membranes allowing the release of chimeras and their extracellular secretion through a Sp2 independent pathway. The addition of the vacuolar sorting determinant Chi to PGIP2 diverts the path of the protein from cell wall to vacuole, suggesting that C domain is a releasing rather than a cell wall sorting signal.
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http://dx.doi.org/10.3389/fpls.2015.00660DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4550104PMC
September 2015

Cellular localization and biochemical characterization of a chimeric fluorescent protein fusion of Arabidopsis cellulose synthase-like A2 inserted into Golgi membrane.

ScientificWorldJournal 2014 14;2014:792420. Epub 2014 Jan 14.

Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Università del Salento (DiSTeBA), Provinciale Lecce-Monteroni, 73100 Lecce, Italy.

Cellulose synthase-like (Csl) genes are believed to encode enzymes for the synthesis of cell wall matrix polysaccharides. The subfamily of CslA is putatively involved in the biosynthesis of β -mannans. Here we report a study on the cellular localization and the enzyme activity of an Arabidopsis CslA family member, AtCslA2. We show that the fluorescent protein fusion AtCslA2-GFP, transiently expressed in tobacco leaf protoplasts, is synthesized in the ER and it accumulates in the Golgi stacks. The chimera is inserted in the Golgi membrane and is functional since membrane preparations obtained by transformed protoplasts carry out the in vitro synthesis of a 14C-mannan starting from GDP-D-[U-14C]mannose as substrate. The enzyme specific activity is increased by approximately 38% in the transformed protoplasts with respect to wild-type. Preliminary tests with proteinase K, biochemical data, and TM domain predictions suggest that the catalytic site of AtCslA2 faces the Golgi lumen.
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http://dx.doi.org/10.1155/2014/792420DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3914377PMC
October 2014

Effect of drying and co-matrix addition on the yield and quality of supercritical CO₂ extracted pumpkin (Cucurbita moschata Duch.) oil.

Food Chem 2014 Apr 23;148:314-20. Epub 2013 Oct 23.

Istituto di Scienze delle Produzioni Alimentari - CNR, Via Prov.le Lecce-Monteroni, 73100 Lecce, Italy.

In this work a process for obtaining high vitamin E and carotenoid yields by supercritical carbon dioxide (SC-CO₂) extraction from pumpkin (Cucurbita moschata Duch.) is described. The results show that the use of a vacuum oven-dried [residual moisture (∼8%)] and milled (70 mesh sieve) pumpkin flesh matrix increased SC-CO₂ extraction yields of total vitamin E and carotenoids of ∼12.0- and ∼8.5-fold, respectively, with respect to the use of a freeze-dried and milled flesh matrix. The addition of milled (35 mesh) pumpkin seeds as co-matrix (1:1, w/w) allowed a further ∼1.6-fold increase in carotenoid yield, besides to a valuable enrichment of the extracted oil in vitamin E (274 mg/100 g oil) and polyunsaturated fatty acids. These findings encourage further studies in order to scale up the process for possible industrial production of high quality bioactive ingredients from pumpkin useful in functional food or cosmeceutical formulation.
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http://dx.doi.org/10.1016/j.foodchem.2013.10.051DOI Listing
April 2014

Comparative genomics reveals candidate carotenoid pathway regulators of ripening watermelon fruit.

BMC Genomics 2013 Nov 12;14:781. Epub 2013 Nov 12.

Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali (Di,S,Te,B,A,), Università del Salento, via Prov,le Lecce-Monteroni,73100 Lecce, Italy.

Background: Many fruits, including watermelon, are proficient in carotenoid accumulation during ripening. While most genes encoding steps in the carotenoid biosynthetic pathway have been cloned, few transcriptional regulators of these genes have been defined to date. Here we describe the identification of a set of putative carotenoid-related transcription factors resulting from fresh watermelon carotenoid and transcriptome analysis during fruit development and ripening. Our goal is to both clarify the expression profiles of carotenoid pathway genes and to identify candidate regulators and molecular targets for crop improvement.

Results: Total carotenoids progressively increased during fruit ripening up to ~55 μg g(-1) fw in red-ripe fruits. Trans-lycopene was the carotenoid that contributed most to this increase. Many of the genes related to carotenoid metabolism displayed changing expression levels during fruit ripening generating a metabolic flux toward carotenoid synthesis. Constitutive low expression of lycopene cyclase genes resulted in lycopene accumulation. RNA-seq expression profiling of watermelon fruit development yielded a set of transcription factors whose expression was correlated with ripening and carotenoid accumulation. Nineteen putative transcription factor genes from watermelon and homologous to tomato carotenoid-associated genes were identified. Among these, six were differentially expressed in the flesh of both species during fruit development and ripening.

Conclusions: Taken together the data suggest that, while the regulation of a common set of metabolic genes likely influences carotenoid synthesis and accumulation in watermelon and tomato fruits during development and ripening, specific and limiting regulators may differ between climacteric and non-climacteric fruits, possibly related to their differential susceptibility to and use of ethylene during ripening.
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http://dx.doi.org/10.1186/1471-2164-14-781DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3840736PMC
November 2013

Possible use of the carbohydrates present in tomato pomace and in byproducts of the supercritical carbon dioxide lycopene extraction process as biomass for bioethanol production.

J Agric Food Chem 2013 Apr 9;61(15):3683-92. Epub 2013 Apr 9.

Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali (DiSTeBA), Università del Salento, Lecce, Italy.

This study provides information about the carbohydrate present in tomato pomace (skins, seeds, and vascular tissues) as well as in the byproducts of the lycopene supercritical carbon dioxide extraction (SC-CO₂) such as tomato serum and exhausted matrix and reports their conversion into bioethanol. The pomace, constituting approximately 4% of the tomato fruit fresh weight, and the SC-CO₂-exhausted matrix were enzyme saccharified with 0.1% Driselase leading to sugar yields of ~383 and ~301 mg/g dw, respectively. Aliquots of the hydrolysates and of the serum (80% tomato sauce fw) were fermented by Saccharomyces cerevisiae . The bioethanol produced from each waste was usually >50% of the calculated theoretical amount, with the exception of the exhausted matrix hydolysate, where a sugar concentration >52.8 g/L inhibited the fermentation process. Furthermore, no differences in the chemical solubility of cell wall polysaccharides were evidenced between the SC-CO₂-lycopene extracted and unextracted matrices. The deduced glycosyl linkage composition and the calculated amount of cell wall polysaccharides remained similar in both matrices, indicating that the SC-CO₂ extraction technology does not affect their structure. Therefore, tomato wastes may well be considered as potential alternatives and low-cost feedstock for bioethanol production.
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http://dx.doi.org/10.1021/jf4005059DOI Listing
April 2013

Effects of sodium alginate bead encapsulation on the storage stability of durum wheat (Triticum durum Desf.) bran oil extracted by supercritical CO2.

J Agric Food Chem 2012 Oct 11;60(42):10689-95. Epub 2012 Oct 11.

Istituto di Scienze delle Produzioni Alimentari-CNR, Via Prov.le Lecce-Monteroni, 73100 Lecce, Italy.

The aim of this study was to investigate the influence of encapsulation on the storage stability of oil extracted by supercritical carbon dioxide from a micronized durum wheat bran fraction. Wheat bran oil was encapsulated in 2% (w/v) sodium alginate beads. Encapsulated and unencapsulated oil samples were stored at 4 or 25 °C, in daylight or darkness, over 90 days, and, at defined time points, subjected to stability evaluation based on fatty acid hydroperoxide production and tocopherol (α, β, and γ forms), tocotrienol (α, β, and γ forms) and carotenoid (lutein, zeaxanthin, and β-carotene) degradation. The encapsulation of the oil into alginate beads significantly increased stability, optimally when stored at 4 °C, maintaining high levels of isoprenoids and low content of fatty acid hydroperoxides over 30 days of storage.
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http://dx.doi.org/10.1021/jf303162mDOI Listing
October 2012

A bifasic response to cadmium stress in carrot: Early acclimatory mechanisms give way to root collapse further to prolonged metal exposure.

Plant Physiol Biochem 2012 Sep 10;58:269-79. Epub 2012 Jul 10.

Dipartimento di Biologia Evolutiva e Funzionale, Università di Parma, Viale delle Scienze 11/A, I-43124 Parma, Italy.

Very few studies have provided information about the effects of cadmium (Cd) at histoanatomical and ultrastructural levels, along with potential localization of the metal in planta. In particular, from this standpoint, almost nothing is known in Daucus carota L. (carrot), a particularly important species for in vitro and in vivo functional investigations. In this work we hypothesized that 36 μM Cd, supplied for 1, 2, 3, 4, 7 and 14 days to 30-day-old in vitro-cultured plants, might induce an early acclimation, but a final collapse of roots and leaves. In fact, as a general feature, a biphasic root response to Cd stress actually took place: in the first phase (1-4 days of Cd exposure), the cytological and functional events observed - by light microscopy, TEM, epifluorescence, as well as by the time-course of thiol-peptide compounds - can be interpreted as acclimatory responses aimed at diminishing the movement of Cd across the root. The second phase (from 4 to 14 days of Cd exposure) was instead characterized by cell hypertrophy, cell-to-cell separation events, increase in α-β-γ-tocopherol levels and, not least, endocytogenic processes, coupled with a dramatic drop in the amount of thiol-peptide compounds. These events led to a progressive root collapse, even if they did not ingenerate macro/microscopic injury symptoms in leaf blades and petioles.
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http://dx.doi.org/10.1016/j.plaphy.2012.07.002DOI Listing
September 2012

Isoprenoid, lipid, and protein contents in intact plastids isolated from mesocarp cells of traditional and high-pigment tomato cultivars at different ripening stages.

J Agric Food Chem 2012 Feb 9;60(7):1764-75. Epub 2012 Feb 9.

Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali (DiSTeBA), Università del Salento, Lecce, Italy.

This study reports quali-quantitative analyses on isoprenoids, phospholipids, neutral lipids, phytosterols, and proteins in purified plastids isolated from fresh fruits of traditional (Donald and Incas) and high-pigment (Kalvert and HLY-18) tomato cultivars at four ripening stages. In all of the investigated cultivars, lycopene, β-catotene, lutein, and total carotenoids varied significantly during ripening. Chromoplasts of red-ripe tomato fruits of high-pigment cultivars accumulated twice as much as lycopene (307.6 and 319.2 μg/mg of plastid proteins in Kalvert and HLY-18, respectively) than ordinary cultivars (178.6 and 151.7 μg/mg of plastid proteins in Donald and Incas, respectively); differences in chlorophyll and α-tocopherol contents were also evidenced. Phospholipids and phytosterols increased during ripening, whereas triglycerides showed a general decrease. Regardless of the stage of ripening, palmitic acid was the major fatty acid in all cultivars (ranging from 35 to 52% of the total fatty acids), followed by stearic, oleic, linoleic, linolenic, and myristic acids, but their relative percentage was affected by ripening. Most of the bands detected on the SDS-PAGEs of plastid proteins were constantly present during chloroplast-to-chromoplast conversion, some others disappeared, and only one, with a molecular weight of ~41.6 kDa, was found to increase in intensity.
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http://dx.doi.org/10.1021/jf204189zDOI Listing
February 2012

Dynamic protein trafficking to the cell wall.

Plant Signal Behav 2011 Jul;6(7):1012-5

DiSTeBA, Università del Salento, Lecce, Italy.

Recently we have studied the secretion pattern of a pectin methylesterase inhibitor protein (PMEI1) and a polygalacturonase inhibitor protein (PGIP2) in tobacco protoplast using the protein fusions, secGFP-PMEI1 and PGIP2-GFP. Both chimeras reach the cell wall by passing through the endomembrane system but using distinct mechanisms and through a pathway distinguishable from the default sorting of a secreted GFP. After reaching the apoplast, sec-GFP-PMEI1 is stably accumulated in the cell wall, while PGIP2-GFP undergoes endocytic trafficking. Here we describe the final localization of PGIP2-GFP in the vacuole, evidenced by co-localization with the marker Aleu-RFP, and show a graphic elaboration of its sorting pattern. A working model taking into consideration the presence of a regulated apoplast-targeted secretion pathway is proposed.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3257782PMC
http://dx.doi.org/10.4161/psb.6.7.15550DOI Listing
July 2011

Protein trafficking to the cell wall occurs through mechanisms distinguishable from default sorting in tobacco.

Plant J 2011 Jan 1;65(2):295-308. Epub 2010 Dec 1.

Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Università del Salento, 73100 Lecce, Italy.

The secretory pathway in plants involves sustained traffic to the cell wall, as matrix components, polysaccharides and proteins reach the cell wall through the endomembrane system. We studied the secretion pattern of cell-wall proteins in tobacco protoplasts and leaf epidermal cells using fluorescent forms of a pectin methylesterase inhibitor protein (PMEI1) and a polygalacturonase inhibitor protein (PGIP2). The two most representative protein fusions, secGFP-PMEI1 and PGIP2-GFP, reached the cell wall by passing through ER and Golgi stacks but using distinct mechanisms. secGFP-PMEI1 was linked to a glycosylphosphatidylinositol (GPI) anchor and stably accumulated in the cell wall, regulating the activity of the endogenous pectin methylesterases (PMEs) that are constitutively present in this compartment. A mannosamine-induced non-GPI-anchored form of PMEI1 as well as a form (PMEI1-GFP) that was unable to bind membranes failed to reach the cell wall, and accumulated in the Golgi stacks. In contrast, PGIP2-GFP moved as a soluble cargo protein along the secretory pathway, but was not stably retained in the cell wall, due to internalization to an endosomal compartment and eventually the vacuole. Stable localization of PGIP2 in the wall was observed only in the presence of a specific fungal endopolygalacturonase ligand in the cell wall. Both secGFP-PMEI1 and PGIP2-GFP sorting were distinguishable from that of a secreted GFP, suggesting that rigorous and more complex controls than the simple mechanism of bulk flow are the basis of cell-wall growth and differentiation.
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http://dx.doi.org/10.1111/j.1365-313X.2010.04421.xDOI Listing
January 2011

Optimisation of biological and physical parameters for lycopene supercritical CO2 extraction from ordinary and high-pigment tomato cultivars.

J Sci Food Agric 2010 Aug;90(10):1709-18

Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Università del Salento, Via Prov. le Lecce-Monteroni, Lecce, Italy.

Background: Lycopene is used for several industrial applications. Supercritical CO(2) (SC-CO(2)) extraction from red-ripe tomato fruits is an excellent technique to replace the use of harmful solvents. In this study, starting from red-ripe tomatoes of ordinary and high-lycopene cultivars, the effect of different agronomical and technical aspects on lycopene content, stability and yield was evaluated throughout the production process from fresh tomatoes to the final SC-CO(2)-extracted oleoresin containing lycopene.

Results: Red-ripe tomato cultivars differed in their lycopene content. Irrigation excess or deficit caused an increase in the amount of lycopene in the fruits. Fresh tomatoes were processed into a lyophilised matrix suitable for SC-CO(2) extraction, which could be stored for more than 6 months at -20 degrees C without lycopene loss. Under the optimal extraction conditions, efficiencies of up to 80% were achieved, but the recovery of lycopene in the extracted oleoresin was very low (approximately 24%). Co-extraction of the tomato matrix mixed with a lipid co-matrix allowed the recovery of approximately 90% of lycopene in the oleoresin. Using the high-lycopene cultivars, the yield of total extracted lycopene increased by approximately 60% with respect to the ordinary cultivars. Lipids and other biologically active molecules were present in the oleoresin.

Conclusion: A method for extracting, from a tomato matrix, a natural and solvent-free oleoresin containing lycopene dissolved in a highly unsaturated vegetable oil has been described. The oleoresin represents an excellent product for testing on cancer and cardiovascular disease prevention.
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http://dx.doi.org/10.1002/jsfa.4006DOI Listing
August 2010

In muro feruloylation and oxidative coupling in monocots: a possible role in plant defense against pathogen attacks.

Plant Signal Behav 2009 Mar;4(3):228-30

Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali (DiSTeBA), Università del Salento, Lecce, Italy.

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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2652537PMC
http://dx.doi.org/10.4161/psb.4.3.7883DOI Listing
March 2009

Antioxidant composition in cherry and high-pigment tomato cultivars.

J Agric Food Chem 2006 Apr;54(7):2606-13

Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali (DiSTeBA), Università di Lecce, via prov.le Lecce-Monteroni, 73100 Lecce, Italy.

Fourteen cultivars of cherry tomatoes and four cultivars of high-pigment tomato hybrids were cultivated in southern Italy, and the red-ripe fruits were analyzed for their content in different classes of antioxidants and for their antioxidant activity. Among the different cultivars, significant differences were found between lycopene, beta-carotene, alpha-tocopherol, vitamin C (ascorbic acid and dehydroascorbic acid), and total phenolic and flavonoid contents. LS203 and Corbus appear to be the cultivars with the highest content of lipophilic and hydrophilic antioxidants among cherry tomatoes, respectively. All cultivars of high-pigment tomato hybrids showed an expected exceptionally high lycopene content. Among them, the highest content of lipophilic and hydrophilic antioxidants was found in cv. HLY 13. Hydrophilic and lipophilic antioxidant activities were both significantly influenced by genotype. Such results highlight an existing unexploited variability in tomato germplasm and stress the need to evaluate the biodiversity and to support conventional breeding programs to improve tomato nutritional value.
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http://dx.doi.org/10.1021/jf052920cDOI Listing
April 2006