Studio del profilo metabolico dei sistemi biologici valutato mediante la tecnica spettroscopica: risonanza magnetica nucleare
Author(s)
Piccioni, Fabiana
Date Issued
February 8, 2011
Type
Doctoral Thesis
Abstract
The “omic” sciences, genomics, proteomics, and metabolomics, are
complementary approaches which are used in order to give a complete
vision of the entire biological system. In this thesis the metabolomic
approach, that is the deepening of the metabolic profiles of seeds
derived from the transgenic maize variety PR33P67 and the
corresponding traditional variety PR33P66, has been used. One- and
two-dimensional NMR techniques were used, in order to give
information about the actual status of the system by defining the real
phenotype. The Nuclear Magnetic Resonance is the technique of choice
for the metabolic investigation, because it allows us to obtain
identification and quantification data of many metabolites which
determine the biological complex; besides it is a technique that is not
destructive but it permits, at the same time, to detect the data in short
time.
The GM maize seed metabolic profile is of particular interest because
maize products are an important source of nutrients and, therefore, an
essential part of the human diet (both through direct consumption and
animal feeds). The transgenic variety carries a functional Cry1A(b)
gene, which confers to the plant the ability to produce Bt insect toxin.
About forty water-soluble metabolites in the maize seed extracts were
identified, providing a more complete 1H and 13C NMR assignment with
respect to the assignment reported in the literature. In particular,
ethanol, lactic acid, citric acid, lysine, arginine, glycine-betaine,
raffinose, trehalose, -galactose, and adenine were identified for the first
time in the 1H NMR spectrum of maize seed extracts. The 1H spectra of
transgenic and non-transgenic maize seed samples turned out to be
conservative, showing the same signals and therefore the same
metabolites. However, a higher concentration of ethanol, citric acid,
2
glycine-betaine, trehalose, as well as of another compound not yet
completely identified, was observed in the transgenic extracts than in
non-transgenic samples. So, it was possible to discriminate between
transgenic and non-transgenic metabolic profilings through the use of an
appropriate statistical analysis.
The metabolic approach (as well as the genomic and proteomic
approach) has had a great success in the scientific research and also in
the nutrition field, above all in transgenic food, because it is important
to determine the health status and safety of the product.
Additional information
Dottorato di ricerca in Genetica e biologia cellulare
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