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Tesi etd-03022014-182211


Thesis type
Tesi di dottorato di ricerca
Author
BARBERINI, SARA
URN
etd-03022014-182211
Title
Biotechnological approach in Lamiaceae species for the production of antioxidant and antibacterial compounds
Settore scientifico disciplinare
BIO/04
Corso di studi
SCIENZE BIOLOGICHE E MOLECOLARI
Commissione
tutor Dott. Pistelli, Laura
commissario Ruffoni, Barbara
commissario Natali, Lucia
Parole chiave
  • Rosmarinus officinalis
  • rosmarinic acid
  • in vitro cultures
  • HPPR
  • carnosic acid
  • Salvia officinalis
Data inizio appello
18/03/2014;
Consultabilità
completa
Riassunto analitico
The interest in natural-derived molecules rosmarinic acid (RA) and carnosic <br>acid (CA) has raised up during the last years due to their well documented <br>antioxidant properties: they are in fact used in foodstuff as preserving agent <br>as well as in pharmacology due to their antibacterial and medicinal properties. <br>In vitro cultures of medicinal plants are considered an alternative way to <br>conventional methods for the production of valuable secondary metabolites; <br>undifferentiated cells (callus and cell suspensions) are also suitable for both <br>plant biomass production and scaling-up and for the study of metabolites <br>biosynthesis. <br>In this work Salvia officinalis L. (common sage) cell suspension cultures were <br>established, and a specific cell line was selected for the high antioxidant <br>capacity of its methanolic extract, which was characterized by a high content <br>of RA. Scavenger activity (DPPH test) and total RA content were evaluated <br>during cell growth. Gene coding for hydroxyphenylpyruvate reductase, the key-<br>enzyme responsible for the RA metabolic biosynthesis, was cloned from common <br>sage (SoHPPR). Its transcript expression level was monitored during cell <br>suspension cultures, and showed a relationship with scavenger activity and RA <br>yield. Our results suggest the potential use of this gene as a marker and <br>target for the modulation of RA production in controlled conditions. In <br>addition, the optimum conditions for Agrobacterium-mediated transformation were <br>determined by monitoring the transient expression of β–Glucuronidase (GUS) <br>marker gene in callus culture. <br>We also set up a protocol for the in vitro culture of Rosmarinus officinalis, <br>one the few species able to synthesize the phenolic diterpene CA. The target of <br>this study was to evaluate the capacity of different tissues of synthesize CA. <br>Our results suggest that all the tissues can accumulate varying amounts of CA, <br>depending on the differentiation grade of the cell culture type: among the <br>different culture types, neo-formed shoots coming from irradiated calli <br>accumulated the highest content of CA. Finally we evaluated whether CA extract <br>may be used as a natural substitute of antibiotics commonly used in plant <br>tissue cultures: our data suggest a bacteriostatic activity of CA against <br>common pathogens without affecting plant growth and physiology.
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