Wang Ling-Ru, Tang Ji-Zi-Hao, Zhu Shu-Ting, Wu Na, Nie Zhi-Kui, Shi Tian-Qiong
School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, 210023, China.
College of Marine and Bioengineering, Yancheng Institute of Technology, Yancheng, China.
Synth Syst Biotechnol. 2024 Dec 20;10(2):373-380. doi: 10.1016/j.synbio.2024.12.004. eCollection 2025 Jun.
Abscisic acid (ABA) is an important plant growth regulator with broad applications in agriculture, forestry, and other fields. Currently, the industrial production of ABA primarily relies on microbial fermentation using , but its genetic toolbox is limited. To address this, we first screened 10 strong constitutive promoters from the genome of through transcriptomic analysis. The expression levels of the promoters covered a range of 3-4 orders of magnitude according to the measured β-glucuronidase activity. Subsequently, four promoters of different strength were used to balance the cofactor supply in . Overexpression of NADH kinase using the medium-strength promoter significantly enhanced ABA production, resulting in a 32.26 % increase compared to the control. Finally, by combining promoter engineering with a push-pull strategy, we optimized the biosynthesis of ABA. The recombinant strain Pthi4:hmgr-Pef1a:a4, overexpressing HMGR under the promoter and Bcaba4 under the promoter, achieved an ABA titer of 1.18 g/L, a 58.92 % increase. To our best knowledge, this is the first constitutive promoter library suitable for , providing important tools for the industrial production of ABA.
脱落酸（ABA）是一种重要的植物生长调节剂，在农业、林业等领域有广泛应用。目前，ABA的工业化生产主要依赖微生物发酵，但用于该生产的遗传工具较为有限。为解决这一问题，我们首先通过转录组分析从[具体物种]基因组中筛选出10个强组成型启动子。根据所测β-葡萄糖醛酸酶活性，这些启动子的表达水平覆盖了3到4个数量级。随后，使用四个不同强度的启动子来平衡[具体微生物]中的辅因子供应。使用中等强度启动子[具体启动子名称]过表达NADH激酶显著提高了ABA产量，与对照相比增加了32.26%。最后，通过将启动子工程与推拉策略相结合，我们优化了ABA的生物合成。在[具体启动子名称]启动子下过表达HMGR且在[具体启动子名称]启动子下过表达Bcaba4的重组菌株Pthi4:hmgr-Pef1a:a4，ABA产量达到1.18 g/L，提高了58.92%。据我们所知，这是首个适用于[具体微生物]的组成型启动子文库，为ABA的工业化生产提供了重要工具。
