Ph.D Scholarship Programme "Heraclitus II"

Plants are characterized by complex biochemical pathways, which result in products - metabolites known as natural products or secondary metabolites. Terpenoids are the largest group of natural products, including triterpenoids, such as a- and b-amyrin and lupeol. The precursor of the biosynthetic pathway is squalene and its oxidized form 2,3-oxidosqualene. The latter can be converted either to sterols or triterpenoids by enzymes called oxidosqualene cyclases (OSCs). Cyclization events of 2,3-oxidosqualene represent a branch point between primary and secondary metabolism. Sterols are well studied compounds in plants and animals, while triterpenoids have not been studied sufficiently, and information in literature is quite limited. Recent findings suggest that genes involved in the biosynthesis of these molecules are organized in clusters in plant genomes. In oat, triterpenoid saponin biosynthesis involves eight genetic loci with no significant homology between them. Recently, similar gene clusters were found in Arabidopsis. Our in silico analysis of the Lotus japonicus genome indicates the existance of at least one similar gene cluster, which will be characterized and validated in this project. The triterpene profile content will be also investigated under various physiological conditions. This study will also explore the physiological functions of terpenoids in roots and nodules of L.japonicus during plant growth. L.japonicus was chosen because of the availability of significant scientific tools (genomic and cDNA libraries, plant mutants etc). Additionally, L.japonicus offers the opportunity to explore the role of terpenoids in nodules, specialized plant organs arising after plant colonization by soil bacteria, rhizobia.

Παραδοτέα έργου δημοσίως προσβάσιμα: 

Ph.D Thesis

PSE Young Scientists Meeting 2011.docx

TERPNET 2011 10th International Meeting.pdf