Project description:We sought to determine the transcriptomic impacts of artemisinin, Artemisia annua extract, and Artemisia afra extract on M. tuberculosis. Log phase cultures were treated with lethal doses for four hours or with inhibitory or sub-inhibitory doses for 24 hours. RNA was collected from untreated controls at the same timepoint.
Project description:There is growing interest to apply proteomics to other organisms than just the biomedically relevant and important species such as human, mouse or rat. However, one of the main hurdles for successful application of proteomics to the organism of interest is still the availability of a well annotated and curated (genomic) database that can be used to search the (mainly MS-based) proteomic data for protein identification. Thus, the field of proteogenomics is increasingly becoming important with the aim to support the annotation of genomic sequence data by exploiting the information that is obtained through proteomics from the identification and characterization of the actual gene products/expression. Here, we have studied the organism Artemisia annua, which is a Chinese medicinal plant endemic to northern parts of China. A. annua is crucial to world health programs as it is currently the sole source for biosynthetically produced artemisinin, the anitmalarial pro-drug compound that has been the last line of defence against malaria for decades.
Project description:Purpose: UV-B radiation is a pivotal photomorphogenic signal and positively regulates plant growth and metabolite biosynthesis. In order to elucidate the transcriptional regulation mechanism underlying UV-B-induced artemisinin and flavonoid biosynthesis in Artemisia annua, the transcriptional response of A. annua leaves to UV-B radiation was analyzed using the Illumina transcriptome sequencing. Methods: For UV-B treatment, six-week-old A. annua seedlings growing under normal growth condition were supplemented with extra narrowband UV-B lamps (Philips TL20W/01RS; 1.5 μmol·m-2·s-1)(Yin et al. 2016). The most recently expanded leaf for each A. annua seedling was collected at 0, 2, 4 and 6 hours after exposure to UV-B radiation. Results: A total of 10706 differentially expressed genes including 533 transcription factors, were identified. Based on the expression trends of the differentially expressed factors as well as artemisinin and flavonoid biosynthesis genes, we speculated that transcription factors belonging to 6 clusters were most likely to be involved in the regulation of artemisinin and/or flavonoid biosynthesis. The regulatory relationship between transcription factors and artemisinin/flavonoid biosynthetic genes was further studied. Dual-LUC assays results showed that AaMYB6 is a positive regulator of AaLDOX, which belongs to flavonoid biosynthesis pathway. In addition, we identified a R2R3MYB transcription factor, AaMYB4 which positively mediated both artemisinin and flavonoid biosynthesis pathways by activating the expression of AaADS and AaDBR2 in artemisinin biosynthesis pathway and AaUFGT in flavonoid biosynthesis pathway. Conclusions: our findings provide fundamental knowledge for the further analysis of the parallel transcriptional regulation of artemisinin and flavonoid biosynthesis in A. annua L. under UV-B radiation.