Department of Chemistry and Biomedical Sciences, Linnaeus University, SE-38192 Kalmar, Sweden.
Department of Chemistry and Biomedical Sciences, Linnaeus University, SE-38192 Kalmar, Sweden.
Phytochemistry. 2014 Jun;102:89-96. doi: 10.1016/j.phytochem.2014.02.011. Epub 2014 Mar 11.
The effective anti-malarial medicine artemisinin is costly because of the low content in Artemisia annua. Genetic engineering of A. annua is one of the most promising approaches to improve the yield of artemisinin. In this work, the transcription factor AaWRKY1, which is thought to be involved in the regulation of artemisinin biosynthesis, was cloned from A. annua var. Chongqing and overexpressed using the CaMV35S promoter or the trichome-specific CYP71AV1 promoter in stably transformed A. annua plants. The transcript level of AaWRKY1 was increased more than one hundred times under the CaMV35S promoter and about 40 times under the CYP71AV1 promoter. The overexpressed AaWRKY1 activated the transcription of CYP71AV1 and moreover the trichome-specific overexpression of AaWRKY1 improved the transcription of CYP71AV1 much more effectively than the constitutive overexpression of AaWRKY1, i.e. up to 33 times as compared to the wild-type plant. However the transcription levels of FDS, ADS, and DBR2 did not change significantly in transgenic plants. The significantly up-regulated CYP71AV1 promoted artemisinin biosynthesis, i.e. up to about 1.8 times as compared to the wild-type plant. It is demonstrated that trichome-specific overexpression of AaWRKY1 can significantly activate the transcription of CYP71AV1 and the up-regulated CYP71AV1 promotes artemisinin biosynthesis.
高效抗疟药物青蒿素的含量较低，因此成本高昂。对黄花蒿进行基因工程改造是提高青蒿素产量最有前途的方法之一。本研究从黄花蒿重庆变种中克隆出一个转录因子 AaWRKY1，该转录因子可能参与青蒿素生物合成的调控，并用 CaMV35S 启动子或毛状体特异性 CYP71AV1 启动子在稳定转化的黄花蒿植物中过表达。在 CaMV35S 启动子的作用下，AaWRKY1 的转录水平提高了 100 多倍，在 CYP71AV1 启动子的作用下提高了约 40 倍。过表达的 AaWRKY1 激活了 CYP71AV1 的转录，并且毛状体特异性过表达 AaWRKY1 比组成型过表达 AaWRKY1 更有效地激活 CYP71AV1 的转录，与野生型植物相比，转录水平提高了 33 倍。然而，转基因植物中 FDS、ADS 和 DBR2 的转录水平没有明显变化。显著上调的 CYP71AV1 促进了青蒿素的生物合成，与野生型植物相比，提高了约 1.8 倍。研究表明，毛状体特异性过表达 AaWRKY1 可以显著激活 CYP71AV1 的转录，而上调的 CYP71AV1 则促进了青蒿素的生物合成。
