A field-grown transgenic tomato line expressing higher levels of polyamines reveals legume cover crop mulch-specific perturbations in fruit phenotype at the levels of metabolite profiles, gene expression, and agronomic characteristics

Genetic modification of crop plants to introduce desirable traits such as nutritional enhancement, disease and pest resistance, and enhanced crop productivity is increasingly seen as a promising technology for sustainable agriculture and boosting food production in the world. Independently, cultural practices that utilize alternative agriculture strategies including organic cultivation subscribe to sustainable agriculture by limiting chemical usage and reduced tillage. How the two together affect fruit metabolism or plant growth in the field or whether they are compatible has not yet been tested. Fruit-specific yeast S-adenosylmethionine decarboxylase (ySAMdc) line 579HO, and a control line 556AZ were grown in leguminous hairy vetch (Vicia villosa Roth) (HV) mulch and conventional black polyethylene (BP) mulch, and their fruit analysed. Significant genotype×mulch-dependent interactions on fruit phenotype were exemplified by differential profiles of 20 fruit metabolites such as amino acids, sugars, and organic acids. Expression patterns of the ySAMdc transgene, and tomato SAMdc, E8, PEPC, and ICDHc genes were compared between the two lines as a function of growth on either BP or HV mulch. HV mulch significantly stimulated the accumulation of asparagine, glutamate, glutamine, choline, and citrate concomitant with a decrease in glucose in the 556AZ fruits during ripening as compared to BP. It enables a metabolic system in tomato somewhat akin to the one in higher polyamine-accumulating transgenic fruit that have higher phytonutrient content. Finally, synergism was found between HV mulch and transgenic tomato in up-regulating N:C indicator genes PEPC and ICDHc in the fruit

Cupricyclins, Novel Redox-Active Metallopeptides Based on Conotoxins Scaffold

Highly stable natural scaffolds which tolerate multiple amino acid substitutions represent the ideal starting point for the application of rational redesign strategies to develop new catalysts of potential biomedical and biotechnological interest. The knottins family of disulphide-constrained peptides display the desired characteristics, being highly stable and characterized by hypervariability of the inter-cysteine loops. The potential of knottins as scaffolds for the design of novel copper-based biocatalysts has been tested by engineering a metal binding site on two different variants of an ω-conotoxin, a neurotoxic peptide belonging to the knottins family. The binding site has been designed by computational modelling and the redesigned peptides have been synthesized and characterized by optical, fluorescence, electron spin resonance and nuclear magnetic resonance spectroscopy. The novel peptides, named Cupricyclin-1 and -2, bind one Cu2+ ion per molecule with nanomolar affinity. Cupricyclins display redox activity and catalyze the dismutation of superoxide anions with an activity comparable to that of non-peptidic superoxide dismutase mimics. We thus propose knottins as a novel scaffold for the design of catalytically-active mini metalloproteins

Metabolic profile of lettuce leaves by high-field NMR spectra

A detailed analysis of the proton high-field NMR spectra of aqueous and organic extracts of lettuce leaves is reported for the first time. A combination of COSY, TOCSY, H-1-C-13 HSQC, H-1-C-13 HMBC bidimensional sequences and DOSY was used to assign each spin system and to separate the components of the complex patterns. A large number of water-soluble metabolites belonging to different classes such as carbohydrates, polyols, organic acids and amino acids were fully assigned. Moreover, the complex spectra of metabolites extracted in organic solvents belonging to sterols, fatty acids, diacylglycerophospholipids, galactosyldiacylglycerols, sulpholipids, pheophytins, carotenoids and hydrocarbons were also assigned. Copyright (c) 2005 John Wiley & Sons, Ltd

An Improved NMR Study of Liposomes Using 1-Palmitoyl-2-oleoyl-sn-glycero-3-phospatidylcholine as Model

In this paper we report a comparative characterization of Small UnilamellarVesicles (SUVs), Large Unilamellar Vesicles (LUVs) and Multilamellar Vesicles (MLVs)prepared from 1-palmitoyl-2-oleoyl-sn-glycero-3-phospatidylcholine (POPC), carried outusing two NMR techniques, namely High Resolution NMR in solution and HighResolution–Magic Angle Spinning (HR-MAS). The size and size distributions of thesevesicles were investigated using the dynamic light scattering technique. An improvedassignment of the 1H-NMR spectrum of MLVs is also reported

High-field nuclear magnetic resonance (NMR) study of truffles (Tuber aestivum vittadini)

A high-field NMR technique was used to analyze aqueous and organic extracts of truffles (Tuber aestivum vittadini) to characterize their chemical composition. Water-soluble metabolites belonging to different classes such as sugars, polyols, amino acids, and organic acids were almost completely assigned by means of one- and two-dimensional experiments (1H-1H COSY, TOCSY, 1H-13C HSQC, 1H-13C HMBC, and 1H-31P HMBC). The 1H spectral assignment of the cell membrane components such as lipids, sterols, and fatty acids extracted in organic solvents was also performed

Effects of resveratrol on HepG2 cells as revealed by 1H-NMR based metabolic profiling

Background: Resveratrol, a polyphenol found in plant products, has been shown to regulate many cellular processes and to display multiple protective and therapeutic effects. Several in vitro and in vivo studies have demonstrated the influence of resveratrol on multiple intracellular targets that may regulate metabolic homeostasis. Methods: We analysed the metabolic modifications induced by resveratrol treatment in a human hepatoblastoma line, HepG2 cells, using a H-1-NMR spectroscopy-based metabolomics approach that allows the simultaneous screening of multiple metabolic pathways. Results: Results demonstrated that cells cultured in the presence or absence of resveratrol displayed different metabolic profiles: the treatment induced a decreased utilisation of glucose and amino acids for purposes of energy production and synthesis associated to a decreased release of lactate in the culture medium and an increase in succinate utilisation. At the same time, resveratrol treatment slowed the cell cycle in the S phase without inducing apoptosis, and increased Sirt1 expression, also affecting its intracellular localisation. Conclusions: Our results show that the metabolomic analysis of the exometabolome of resveratrol-treated HepG2 cells indicates a metabolic switch from glucose and amino acid utilisation to fat utilisation for the production of energy, and seem in agreement with an effect mediated via AMPK- and Sirt1-activation. General significance: NMR-based metabolomics has been applied in a hepatocyte cell culture model in relation to resveratrol treatment; such an approach could be transferred to evaluate the effects of nutritional compounds with health impact. (C) 2011 Elsevier B.V. All rights reserved

Phytate Degradation by Lactic Acid Bacteria and Yeast during the Wholemeal Dough Fermentation: a 31P NMR Study

myo-Inositol hexaphosphate (IP6) is the main source of phosphorus in cereal grains, and therefore, in bakery products. Different microorganisms such as yeasts and lactic acid bacteria have phytase enzymes able to hydrolyze IP6 during the wholemeal breadmaking. In this paper, the phytase activity of Lactobacillus plantarum, Lactobacillus brevis, Lactobacillus curvatus, and Saccharomyces cerevisiae strains, isolated from southern Italian sourdoughs, is assayed using the 31P NMR technique. The sourdough technology based on the use of lactic acid bacteria in the breadmaking is finally suggested