METABOLIC ENGINEERING OF ALKALOIDS PRODUCTION IN PLANT

Juan PanDepartment of Plant Pathology

OUTLINE

• alkaloids biosynthesis in plant• metabolic engineering• summary

ALKALOIDS- N-containing small molecule - Amino acid derivative- Secondary metabolites- Defense in plant- Pharmaceutical uses

Alkaloid biosynthesisIn plant- monoterpene indole alkaloid (MIA)

Annu. Rev. Plant Biol. 2008. 59:735-69

MIA biosynthesis scheme

Alkaloid biosynthesis in plant- benzylisoquinoline alkaloids (BIAs)

tyrosine (S)-norcoclaurine

Nature chemical biology, 2009, 5 (5): 292-300

dopamine

4-hydroxyphenylacetaldehyde

(S)-reticuline

Alkaloid biosynthesis in plant- tropane alkaloids

Alkaloid biosynthesis in plant- purine alkaloids

Metabolic engineering of alkaloid biosynthesis

- Overexpressing rate- limiting genes- Gene silencing to block pathway- Regulatory element

H6H

PMT and H6H overexpression increased scopolamine production

Proc Natl Acad Sci USA 101: 6786-6791

tyrosine (S)-norcoclaurine

dopamine

4-hydroxyphenylacetaldehyde

(S)-reticuline

COR

Silencing COR blocked morphine biosynthetic pathway

Nat Biotechnol 22: 1559-1566

Nat Biotechnol 22: 1559-1566

Plant Biotechnology Journal (2008) 6, pp. 160–175

Exogenous regulatory factors increased alkaloids production in poppy

SUMMARY

- Overexpression of rate-limiting enzyme for higher alkaloid production- Gene silencing to block certain pathway- Manipulating regulatory elements to increase alkaloid production- Combination of several methods