the-terroir-concept-interpreted-through-grape-berry-metabolomics

The Terroir Concept Interpreted through Grape Berry Metabolomics and Transcriptomics

Terroir refers to the combination of environmental factors that affect the characteristics of crops such as grapevine (Vitis vinifera) according to ...

University of Verona

University of Trento

Phenotypic plasticity refers to the range of phenotypes a single genotype can express as a function of its environment. These phenotypic variations are attributable to the effect of the environment on the expression and function of genes influencing plastic traits. We investigated phenotypic plasticity in grapevine by comparing the berry transcriptome in a single clone of the vegetatively-propagated common grapevine species Vitis vinifera cultivar Corvina through 3 consecutive growth years cultivated in 11 different vineyards in the Verona area of Italy.

The plasticity of the grapevine berry transcriptome.

Induced hypoxia stress on cervical cancer derived cells (HeLa cells) leads to significant changes in their membrane lipid profiles. The lipidome of HeLa cells was characterized by a joint approach wherein liquid chromatography-mass spectrometry (LC-MS) analysis was followed by high resolution NMR measurements. Multivariate data analysis showed apparent separation between control and hypoxia-treated HeLa cells and thus demonstrated hypoxia effects on lipid metabolism. The most striking finding was that hypoxia stimulation significantly reduced the total amount of cellular phosphoinositols (PI) but caused a prominent increase in the amount of lyso phosphocholines (lyso-PC) and lyso phosphoethanolamines (lyso-PE). The observed decrease of PI amount under hypoxic conditions is probably due to the accumulation of cellular myo-inositol, which is known to play a critical role in de novo synthesis of PI. Moreover, our study suggests that polyunsaturated phospholipid species are stronger biomarkers for discriminating the effect of hypoxia treatment. The evaluation of changes in the average unsaturation index (UI) of the membrane lipids acyl chains reveals that UI slightly increases in several lipid classes, thus affecting membrane fluidity and further membrane-dependent functions. The plausible mechanisms by which HeLa cells adapt to hypoxia conditions are also briefly reported.

A lipidomics investigation of the induced hypoxia stress on HeLa cells by using MS and NMR techniques.

Coleps hirtus is a small common freshwater ciliate belonging to the protostomatid group, its body covered by calcified plates assembled to form an armor. Coleps feeds on bacteria, algae, flagellates, living and dead ciliates, animal and plant tissues. To assist its carnivorous feeding the ciliate is equipped with offensive extrusomes (toxicysts), clustering mainly in and around its oral aperture. In this study, we isolated the discharge of the toxicysts from living cells, evaluating its cytotoxic effects against various ciliate species, and demonstrating that it is essential for the effectiveness of Coleps' predatory behavior. The analysis of the toxicyst discharge performed by liquid chromatography-electrospray-mass spectrometry and gas chromatography-mass spectrometry, revealed the presence of a mixture of 19 saturated, monounsaturated and polyunsaturated free fatty acids with the addition of a minor amount of a diterpenoid (phytanic acid).

Chemical offense by means of toxicysts in the freshwater ciliate, Coleps hirtus.

Supercritical carbon dioxide (SC-CO2) treatment is one of the most promising alternative techniques for pasteurization of both liquid and solid food products. The inhibitory effect of SC-CO2 on bacterial growth has been investigated in different species, but the precise mechanism of action remains unknown. Membrane permeabilization has been proposed to be the first event in SC-CO2-mediated inactivation. Flow cytometry, high performance liquid chromatography–electrospray ionization–mass spectrometry and NMR analyses were performed to investigate the effect of SC-CO2 treatment on membrane lipid profile and membrane permeability in Escherichia coli K12. After 15 min of SC-CO2 treatment at 120 bar and 35 °C, the majority of bacterial cells dissipated their membrane potential (95 %) and lost membrane integrity, as 81 % become partially permeabilized and 18 % fully permeabilized. Membrane permeabilization was associated with a 20 % decrease in bacterial biovolume and to a strong (>50 %) reduction in phosphatidylglycerol (PG) membrane lipids, without altering the fatty acid composition and the degree of unsaturation of acyl chains. PGs are thought to play an important role in membrane stability, by reducing motion of phosphatidylethanolamine (PE) along the membrane bilayer, therefore promoting the formation of inter-lipid hydrogen bonds. In addition, the decrease in intracellular pH induced by SC-CO2 likely alters the chemical properties of phospholipids and the PE/PG ratio. Biophysical effects of SC-CO2 thus cause a strong perturbation of membrane architecture in E. coli, and such alterations are likely associated with its strong inactivation effect.

Supercritical CO2 induces marked changes in membrane phospholipids composition in Escherichia coli K12.

In this paper, we report the development of a new method based on HILIC-ESI-MS for the separation of several different membrane lipid classes and their detection on a triple quadrupole mass spectrometer using Precursor Ion (PIS) and Neutral Loss (NL) scanning in positive ion mode. Four different columns were tested for their ability to separate, under different conditions, a mixture of 14 lipid standards containing 7 glycerophospholipids (GPL), 2 glycosphyngolipids (GSL), 3 glycolipids (GL) and 2 betaine lipids (BL). The best separation was obtained using a Lichrosphere DIOL column as stationary phase and water (10mm ammonium acetate)/acetonitrile gradient elution as mobile phase which allows the separation of the 14 lipid classes within 35min runtime. Our method was successfully tested for the separation and analysis of crude lipid extracts obtained from a green alga (Jaoa bullata), a dinoflagellate (Peridinium cinctum) and a plant (Vitis vinifera cv. Corvina).

A fast liquid chromatography-mass Spectrometry methodology for membrane lipid profiling through hydrophilic interaction liquid chromatography.

The definition of the terroir concept is one of the most debated issues in oenology and viticulture. The dynamic interaction among diverse factors including the environment, the grapevine plant and the imposed viticultural techniques means that the wine produced in a given terroir is unique. However, there is an increasing interest to define and quantify the contribution of individual factors to a specific terroir objectively. Here, we characterized the metabolome and transcriptome of berries from a single clone of the Corvina variety cultivated in seven different vineyards, located in three macrozones, over a 3-year trial period.

Towards a scientific interpretation of the terroir concept: plasticity of the grape berry metabolome.

Molecularly imprinted polymers (MIPs) were combined to MALDI-TOF-MS to evaluate a selective enrichment (SE) method for the determination of clinically relevant biomarkers from complex biological samples. The concept was proven with the myocardial injury marker Troponin I (cTnI). In a first part, MIP materials entailed for the recognition of cTnI epitopes (three peptides selected) were prepared and characterized in dimensions (0.7-2μm), dissociation constants (58-817 nM), kinetics of binding (5-60 min), binding capacity (ca. 1.5 µg/mg polymer), imprinting factors (3 > IF > 5) and selectivity for the peptide epitope. Then, the MIPs, incubated with cTnI peptides and spotted on the target with the DHB matrix, were assayed for the desorption of the peptides in MALDI-TOF-MS. The measured detection limit was ca. 300 femtomols. Finally, the MIP-SE MALDI-TOF-MS was tested for its ability to enrich in the cTnI peptides from a complex sample, mimic of serum (i.e. 81 peptides of digested albumin). The MIP-SE MALDI-TOF-MS successfully enriched in cTnI peptides from the complex sample proving the technique could offer a flexible platform to prepare entailed materials suitable for diagnostic purposes.

Molecularly imprinted polymers coupled to matrix assisted laser desorption ionization mass spectrometry for femtomoles detection of cardiac troponin I peptides.

The shape recognition model of olfaction maintains that odorant reception probes physicochemical properties such as size, shape, electric charge, and hydrophobicity of the ligand. Recently, insects were shown to distinguish common from deuterated isotopomers of the same odorant, suggesting the involvement of other molecular properties to odorant reception. Via two-photon functional microscopy we investigated how common and deuterated isoforms of natural odorants are coded within the honeybee brain. Our results provide evidence that (i) different isotopomers generate different neuronal activation maps, (ii) isotopomer sensitivity is a general mechanism common to multiple odorant receptors, and (iii) isotopomer specificity is highly consistent across individuals. This indicates that honeybee's olfactory system discriminates between isotopomers of the same odorant, suggesting that other features, such as molecular vibrations, may contribute to odour signal transduction.

Differential Odour Coding of Isotopomers in the Honeybee Brain.

Here we report the lipid profiles of ten dinoflagellate species originating from different freshwater habitats and grown at 4, 13, or 20°C akin to their natural occurrence. Lipids were determined by High Performance Liquid Chromatography-ElectroSpray Ionization-Mass Spectrometry in positive and negative ion modes. Besides the well-studied monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG) lipids, our study revealed the presence of intact molecular lipid species of trigalactosyldiacylglycerols, betaine diacylglyceryl-carboxyhydroxymethylcholine, sulfolipid sulfoquinovosyldiacylglycerols (SQDG) and phospholipids, in particular phosphatidylcholine, phosphatidylethanolamine and phosphatidylglycerol. In multivariate ordination, the freshwater dinoflagellates studied could be distinguished into two groups based on their lipid profiles. Peridinium aciculiferum, Borghiella dodgei, B. tenuissima and Tovellia coronata belonged to group 1 while Ceratium cornutum, Gymnodinium palustre, Jadwigia applanata, P. cinctum, P. willei, and P. gatunense belonged to group 2. Indicator species analysis evidenced that group 1 was characterized by 36:9 MGDG and 36:9 DGDG and group 2 by 38:9 and 38:10 MGDG, 38:9 and 38:10 DGDG and 34:1 SQDG. We suggest that the grouping of dinoflagellates indicated their range of temperature tolerance. Furthermore, non-thylakoid lipids were linked to dinoflagellate phylogeny based on the large ribosomal sub-unit (28S LSU) rather than their temperature tolerance. Thus certain lipids better reflected habitat adaptation while other lipids better reflected genetic diversity.

Comparative Analysis of Membrane Lipids in Psychrophilic and Mesophilic Freshwater Dinoflagellates.

The molecular events that characterize post-ripening grapevine berries have rarely been investigated and are poorly defined. In particular, a detailed definition of changes occurring during the postharvest dehydration, a process undertaken to make some particularly special wine styles, would be of great interest for both winemakers and plant biologists. We report an exhaustive survey of transcriptomic and metabolomic responses in berries representing six grapevine genotypes subjected to postharvest dehydration under identical controlled conditions. The modulation of phenylpropanoid metabolism clearly distinguished the behavior of genotypes with stilbene accumulation as the major metabolic event, although in genotypes that do not accumulate stilbenes the prevalent variation was the transient accumulation/depletion of anthocyanins and flavonols. The modulation of genes related to phenylpropanoid/stilbene metabolism highlighted the distinct metabolomic plasticity of genotypes, allowing the identification of candidate structural and regulatory genes. In addition to genotype-specific responses, a core set of genes was consistently modulated in all genotypes, representing the common features of berries undergoing dehydration and/or commencing senescence. This included genes controlling ethylene and auxin metabolism as well as genes involved in oxidative and osmotic stress, defense responses, anaerobic respiration, cell wall and carbohydrate metabolism. Several transcription factors were identified that may control these shared processes in the postharvest berry. Changes representing both common and genotype-specific responses to postharvest conditions shed light on the cellular processes taking place in harvested berries stored under dehydrating conditions for several months.

Andrea Anesi

Biotechnology Department

University of Verona

The Terroir Concept Interpreted through Grape Berry Metabolomics and Transcriptomics