Prof. Kexuan Tang
Dr. Qifang Pan
Project Description and Objectives
China has a great resource of medicinal plants. Our project mainly focuses on metabolic regulation and engineering of medicinal plants, such as Artemisia annua and Catharanthus roseus. Among them A. annua has obtained great attention due to the antimalarial agents artemisin and its derivatives. Malaria is one of the most serious health problems in human history, responsible for more than 600,000 deaths last year. Artemisinin-based combination therapies (ACTs) are recommended by WHO to be the best choice for acute malaria. It has saved millions of lives in African countries. The Chinese pharmacologist Youyou Tu received the 2015 Nobel Prize in Physiology or Medicine for her contribution to the artemisinin isolation. Moreover, artemisinin and its derivatives have been found to have antiviral, anticancer, and antischistosomal activities, which makes artemisinin a promising natural product with multifunction. The plant A. annua is the main commercial source of artemisinin. However, the supply is restricted by the low amounts of artemisinin, at a range of 0.1%-1 % dry leaf weight of A. annua. This results in a high cost of for an effective product that most of the poor population of malarial victims in Africa could not afford.
In order to improve the artemisinin content in A. annua by reducing production cost, our project focuses on metabolic engineering of A. annua plants by three main strategies: overexpressing artemisinin biosynthetic pathway key enzyme genes in A. annua, blocking artemisinin biosynthesis competitive pathway key enzyme genes, and transcriptional regulation of artemisinin biosynthesis.
To obtain an artemisinin-high-producing transgenic A. annua plant by metabolic engineering strategies