Shu Guoping, Tang Yueli, Yuan Mingyuan, Wei Ning, Zhang Fangyuan, Yang Chunxian, Lan Xiaozhong, Chen Min, Tang Kexuan, Xiang Lien, Liao Zhihua
Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), Chongqing Engineering Research Centre for Sweet Potato, SWU-TAAHC Medicinal Plant Joint R&D Centre, School of Life Sciences, Southwest University, Chongqing 400715, China.
TAAHC-SWU Medicinal Plant Joint R&D Centre, Xizang Agricultural and Husbandry College, Nyingchi 860000, China.
Acta Pharm Sin B. 2022 Mar;12(3):1500-1513. doi: 10.1016/j.apsb.2021.09.026. Epub 2021 Sep 30.
is the main natural source of artemisinin production. In , extended drought stress severely reduces its biomass and artemisinin production while short-term water-withholding or abscisic acid (ABA) treatment can increase artemisinin biosynthesis. ABA-responsive transcription factor AabZIP1 and JA signaling AaMYC2 have been shown in separate studies to promote artemisinin production by targeting several artemisinin biosynthesis genes. Here, we found AabZIP1 promote the expression of multiple artemisinin biosynthesis genes including and , which AabZIP1 does not directly activate. Subsequently, it was found that AabZIP1 up-regulates expression through direct binding to its promoter, and that AaMYC2 binds to the promoter of to activate its transcription. In addition, AabZIP1 directly transactivates wax biosynthesis genes and . The biosynthesis of artemisinin and cuticular wax and the tolerance of drought stress were significantly increased by overexpression, whereas they were significantly decreased in RNAi- plants. Collectively, we have uncovered the AabZIP1-AaMYC2 transcriptional module as a point of cross-talk between ABA and JA signaling in artemisinin biosynthesis, which may have general implications. We have also identified AabZIP1 as a promising candidate gene for the development of plants with high artemisinin content and drought tolerance in metabolic engineering breeding.
是青蒿素生产的主要天然来源。在[具体情境未提及]中，长期干旱胁迫会严重降低其生物量和青蒿素产量，而短期停水或脱落酸（ABA）处理可增加青蒿素生物合成。在单独的研究中已表明，ABA响应转录因子AabZIP1和茉莉酸（JA）信号传导因子AaMYC2通过靶向多个青蒿素生物合成基因来促进青蒿素生产。在此，我们发现AabZIP1促进包括[具体基因未提及]和[具体基因未提及]在内的多个青蒿素生物合成基因的表达，而AabZIP1并不直接激活这些基因。随后，发现AabZIP1通过直接结合其启动子上调[具体基因未提及]的表达，并且AaMYC2与[具体基因未提及]的启动子结合以激活其转录。此外，AabZIP1直接反式激活蜡生物合成基因[具体基因未提及]和[具体基因未提及]。过表达[具体基因未提及]显著提高了青蒿素和表皮蜡的生物合成以及干旱胁迫耐受性，而在RNA干扰（RNAi）植株中它们显著降低。总体而言，我们揭示了AabZIP1 - AaMYC2转录模块作为青蒿素生物合成中ABA和JA信号传导之间的一个相互作用点，这可能具有普遍意义。我们还确定AabZIP1是代谢工程育种中开发高青蒿素含量和耐旱性青蒿植株的一个有前景的候选基因。
