Genomic structure of amorpha-4, 11-diene synthase in artemisia annua L.

Abstract

Artemisia annua, an indigenous plant to Korea, accumulates an antimalarial sesquiterpene, artemisinin. Amorpha-4,11-diene synthase (ADS) is a sesquiterpene synthase in artemisinin biosynthesis pathway. Open reading frame of ADS gene is described previously. To compose genomic structure of ADS, 5''-upstream region and introns of ADS gene were found. Firstly, to search the useful elements of ADS gene promoter, 5''-upstream region of 502 bp-long was isolated from the translation start codon. Promoter elements of TATA box, H box, G box, BOX IV were found in 5''- upstream region of ADS gene. Secondly, five pairs of primers were designed from the expected regions of open reading frame of the synthase gene, and the original PCR amplicons of genomic DNA were sequenced directly. Six introns, which were mostly same as those reported from Chinese race were found. However, 1,729 bp-long second intron had an extra sequence of 34 bp compared to the Chinese race. The discordance of the second intron of amorpha-4,11-diene synthase between regional races of A. annua inhabiting China and Korea is discussed in the aspect of evolutionary and functional implications.