Artemisinin accumulation and enhanced net photosynthetic rate in Qinghao (Artemisia annua L.) hardened in vitro in enriched-CO<inf>2</inf> photoautotrophic conditions

Abstract

In vitro hardening or acclimatisation is one of the most practices in plant tissue culture, especially medicinal plant namely Artemisia annua (qinghao), which is very sensitive to ex vitro environments in transplanting process. The aim of this investigation was to enhance the production of artemisinin, sesquiterpene bioactive compound to cure parasite as a major antimalarial drug, and develop a high photosynthetic rate in qinghao plantlets, using photoautotrophic CO 2 -enrichment. The artemisinin content in acclimatised plantlets grown in liquid MS medium with vermiculite supporting material was increased when compared to controlled plantlets. Net photosynthetic rate (P n ) and growth characters were greatest in the acclimatized plantlets grown in liquid medium with 65±5% relative humidity, leading to the highest survival percentage (81.7%) when transplanted to ex-vitro conditions. In addition, the Pn and growth performance of hardened plantlets in enriched CO 2 condition were better than those of hardened plantlets without CO 2 enrichment, leading to an improvement in the ex-vitro survival percentage (91.7%). Healthy plantlets of qinghao can be produced effectively in vitro, using a liquid medium with CO 2 enrichment in photoautotrophic conditions, resulting in plants to survive in exvitro environments, as well as having effective artemisinin accumulation.