A glandular trichome-specific monoterpene alcohol dehydrogenase from Artemisia annua

• Published in: Phytochemistry (Oxford) Vol. 71; no. 11; pp. 1264 - 1269
• Main Authors: Polichuk, Devin R., Zhang, Yansheng, Reed, Darwin W., Schmidt, Janice F., Covello, Patrick S.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Ltd 01-08-2010; Elsevier
• Subjects: alcohol dehydrogenase; Alcohol Dehydrogenase - genetics; Alcohol Dehydrogenase - metabolism; amino acid sequences; Artemisia annua; Artemisia annua - chemistry; Artemisia annua - enzymology; Artemisia annua - genetics; Asteraceae; Biological and medical sciences; Chemical constitution; Dehydrogenase; enzymes; essential oils; expressed sequence tags; Fundamental and applied biological sciences. Psychology; General pharmacology; genes; isoprenoids; ketones; Medical sciences; medicinal plants; medicinal properties; molecular sequence data; Molecular Structure; Monoterpene; Monoterpenes - chemistry; Monoterpenes - isolation & purification; monoterpenoids; multigene family; nucleotide sequences; Oils, Volatile - chemistry; Pharmacognosy. Homeopathy. Health food; Pharmacology. Drug treatments; plant glands; Plant physiology and development; plant proteins; protein synthesis; Seeds - chemistry; sequence alignment; sequence analysis; Trichome; trichomes; SDR; AAFB; EST; IPP; Dehydrogenase; Trichome; ADH2; Artemisia annua; Asteraceae; GSTSUB; Monoterpene; AAGST; DMAPP; MDR; Enzyme; Pharmacognosy; Chemical structure; Alcohol dehydrogenase; Compositae; Medicinal plant; Dicotyledones; Angiospermae; Plant origin; Spermatophyta; Oxidoreductases
• ISSN: 0031-9422; 1873-3700
• DOI: 10.1016/j.phytochem.2010.04.026

Cloning and characterization of a trichome-specific alcohol dehydrogenase from
Artemisia annua is described that preferentially oxidizes monoterpenoid secondary alcohols including artemisia alcohol, borneol and carveol.
The major components of the isoprenoid-rich essential oil of
Artemisia annua L. accumulate in the subcuticular sac of glandular secretory trichomes. As part of an effort to understand isoprenoid biosynthesis in
A. annua, an expressed sequence tag (EST) collection was investigated for evidence of genes encoding trichome-specific enzymes. This analysis established that a gene denoted
Adh2, encodes an alcohol dehydrogenase and shows a high expression level in glandular trichomes relative to other tissues. The gene product, ADH2, has up to 61% amino acid identity to members of the short chain alcohol dehydrogenase/reductase (SDR) superfamily, including
Forsythia
×
intermedia secoisolariciresinol dehydrogenase (49.8% identity). Through
in vitro biochemical analysis, ADH2 was found to show a strong preference for monoterpenoid secondary alcohols including carveol, borneol and artemisia alcohol. These results indicate a role for ADH2 in monoterpenoid ketone biosynthesis in
A. annua glandular trichomes.