关键词: 青蒿, 红光, 转录因子, 青蒿素

Abstract:

Artemisinin is an important sesquiterpene lactone endoperoxide which is isolated from Chinese medicinal plants Artemisia annua L.. Artemisinin-based combination therapies (ACTs) are recommended as the best treatment for malaria. However, the content of artemisinin in A. annua is low (0.01%~1% of dry weight). Light is a crucial physical factor for plant growth and development. More importantly, it is a significant regulator in the biosynthesis of secondary metabolites. Several studies show that light could regulate the biosynthesis of artemisinin, but its regulatory mechanism is still unknown. According to analysis of a large set of RNA sequencing (RNA-Seq) data of A. annua with red light (40 μmol/m2·s) treatment, AaBPF1, one MYB transcription factor, was screened. The AaBPF1 gene contained a 1 932 bp open reading frame, which encoded a protein with 643 amino acids, and its expression level was induced by red light. The expression pattern of AaBPF1 was similar to those of synthase genes for artemisinin. Subsequently, the expression of synthase genes for artemisinin was detected by Dual-Luciferase Reporter Assay System, and the expression of the target genes and the content of artemisinin in transgenic A. annua plants were analyzed. The results showed that AaBPF1 could significantly activate the expression of ADS and CYP71AV1. The study demonstrated that the transcription factor AaBPF1 might positively regulate the biosynthesis of artemisinin by activating the expression of synthase genes for artemisinin.

Key words: Artemisia annua L., red light, transcription factors, artemisinin