Abstract:

A full-length cDNA (apod1) encoding a peroxidase was isolated from Artemisia annua L. using rapid amplification of cDNA end (RACE) strategy. The peroxidase activity of recombinant protein (APOD1) expressed in E. coli BL21 (DE3) pLysS cells was about 1.8-fold higher with guaiacol than ascorbate, which indicated that APOD1 was a plant classical peroxidase (class Ⅲ peroxidase). The deduced amino acids of apod1 had 42.0% homology to the peroxidase from Lupinus albus, 36.2% to Armoracia rusticana, 38.9% to Triticum aestivum, 33.6% to Nicotiana tabacum and 32.8% to Lycopersicon esculentum, respectively. Northern blotting analysis showed that apod1 was expressed in the roots, stems and leaves of A. annua. APOD1 favored the bioconversion of artemisinic acid to artemisinin in the cell-free extracts of A. annua indirectly but no oxidization with artemisinic acid as the only substrate. Key words: Artemisia annua ; artemisinic acid; artemisinin; peroxidase