Studies on Anthriscus sylvestris L (Hoffm.). Metabolic engineering of combinatorial biosynthesis of podophyllotoxin

PhD ceremony: Ms. O. Hendrawati, 14.30 uur, Aula Academiegebouw, Broerstraat 5, Groningen

Dissertation: Studies on Anthriscus sylvestris L (Hoffm.). Metabolic engineering of combinatorial biosynthesis of podophyllotoxin

Promotor(s): prof. O. Keyser, prof. W.J. Quax

Faculty: Mathematics and Natural Sciences

The results of Oktavia Hendrawati emphasize a future prospect of engineering Anthriscus sylvestris for (epi)podophyllotoxin production.

In recent years, strategies and techniques for the production of natural compounds (plant derived fine chemicals) and / or the breeding of medicinal and aromatic plants have expanded. Metabolic engineering and pathway optimization with the aim to reduce costs and to increase productivity have become a main focus of academia and industry. A. sylvestris allows an interesting approach for genetic modification to directly produce (epi)podophyllotoxin in the plant, because of the high content of deoxypodophyllotoxin and its close biosynthetic relationship with podophyllotoxin. A. sylvestris is a wild plant in northern Europe and other temperate regions of the world. Human cytochrome P450 3A4 in E.coli DH5Alpha selectively hydroxylates deoxypodophyllotoxin at the C7 position yielding epipodophyllotoxin, the diastereoisomer of podophyllotoxin. Human cytochrome P450 3A4 was transferred into A. sylvestris via Agrobacterium tumefaciens. The A. sylvestris callus tissue was transformed with A. tumefaciens carrying the human P450 3A4 gene and the cells were regenerated. The transformed regenerated plants now were able to form epipodophyllotoxin in low amounts. Further optimization of the plasmid construction such as the promoter, P450 3A4 gene, and targeting signal peptide are needed to increase the level of expression of human P450 3A4 gene which should lead to a higher level of (epi)podophyllotoxin production. This engineering strategy may be applied to other plants producing deoxypodophyllotoxin.