Artemisinin biosynthesis enhancement in transgenic Artemisia annua plants by downregulation of the β-caryophyllene synthase gene.

TL;DR: It is demonstrated that the inhibition pathway in the precursor competition for artemisinin biosynthesis by anti-sense technology is an effective means of increasing the art Artemisinin content of A. annua plants.

Abstract: Artemisinin is an effective antimalarial drug isolated from the medicinal plant Artemisia annua L. Due to its increasing market demand and the low yield in A. annua, there is a great interest in increasing its production. In this paper, in an attempt to increase artemisinin content of A. ANNUA by suppressing the expression of β-caryophyllene synthase, a sesquiterpene synthase competing as a precursor of artemisinin, the antisense fragment (750 bp) of β-caryophyllene synthase cDNA was inserted into the plant expression vector pBI121 and introduced into A. annua by Agrobacterium-mediated transformation. PCR and Southern hybridization confirmed the stable integration of multiple copies of the transgene in 5 different transgenic lines of A. annua. Reverse transcription PCR showed that the expression of endogenous CPS in the transgenic lines was significantly lower than that in the wild-type control A. annua plants, and β-caryophyllene content decreased sharply in the transgenic lines in comparison to the control. The artemisinin content of one of the transgenic lines showed an increase of 54.9 % compared with the wild-type control. The present study demonstrated that the inhibition pathway in the precursor competition for artemisinin biosynthesis by anti-sense technology is an effective means of increasing the artemisinin content of A. annua plants.