Increased Accumulation of Artemisinin and Anthocyanins in Artemisia annua Expressing the Arabidopsis Blue Light Receptor CRY1

Abstract

Artemisinin, an effective drug against Plasmodium species that cause malaria, is a sesquiterpene lactone isolated from Artemisia annua. The yield of artemisinin in plants is relatively low, and it is influenced by various environmental growing conditions. In Arabidopsis, cryptochrome 1 (CRY1) is one of the key receptors that perceive light signals, and its overexpression promotes accumulation of secondary metabolites. In this study, overexpression of Arabidopsis CRY1 in A. annua resulted in increased accumulation of both artemisinin and anthocyanins. Under blue light, transgenic plants expressing high level of AtCRY1 showed a variety of blue light-induced responses, including inhibition of hypocotyl elongation and cotyledon expansion, dwarfism, and purpuring of aerial organs. Reverse transcription polymerase chain reaction analysis revealed that expression levels of the phenylalanine ammonia-lyase-and chalcone synthase-encoding genes were elevated and that anthocyanin accumulation was increased. Expression analysis of genes encoding farnesyl diphosphate synthase (FPS), amorpha-4,11-diene synthase (ADS), and CYP71AV1, three important enzymes in artemisinin biosynthesis, indicated that transcript abundance of all three genes, FPS, ADS, and CYP71AV1, increased in AtCRY1 plants. Based on high performance liquid chromatography analysis, artemisinin content in these plants increased by 30∼40%, when compared to control. These results have demonstrated that alteration of light signaling components could provide a viable approach for enhancing production of the secondary metabolite artemisinin.

The Jasmonate-Responsive AP2/ERF Transcription Factors AaERF1 and AaERF2 Positively Regulate Artemisinin Biosynthesis in Artemisia annua L.

“…A WRKY transcription factor, AaWRKY1, was reported to positively regulate the transcription of ADS by binding to the W-box in its promoter (Ma et al, 2009). In addition, we found that overexpression of AtCRY1, a blue light receptor of Arabidopsis, led to increased accumulation of artemisinin (Hong et al, 2009), implying a correlation between light signaling and artemisinin biosynthesis.…”

Photoperiod and shading regulate coloration and anthocyanin accumulation in the leaves of malus crabapples

“…However, the effect of light intensity on anthocyanin biosynthesis and color change in leaves has been reported at the molecular level for only a few plant species, such as Arabidopsis, petunia and coleus (Albert et al 2009;Hong et al 2009;Nguyen and Cin 2009;Rowan et al 2009). Light intensity is closely associated with the rate of color transition, anthocyanin accumulation and the expression of anthocyanin-related genes in coleus (Nguyen and Cin 2009).…”

Characterization of the Jasmonate Biosynthetic Gene Allene Oxide Cyclase in Artemisia annua L., Source of the Antimalarial Drug Artemisinin

“…Therefore, great efforts have been made to try to increase artemisinin production. As the total synthesis of artemisinin is difficult and costly, many other approaches have been attempted to improve artemisinin production, such as environmental factor manipulation for A. annua plants, a semisynthetic microbial process for the production of artemisinin, the fast-track breeding of A. annua and the genetic engineering (Putalun et al 2007;Dietrich et al 2009;Graham et al 2010;Zhang et al 2009;Hong et al 2009). …”