Abstract: Coronatine (COR) is a secondary metabolite produced by several pathovars of Pseudomonas syringae, and it is a novel plant growth regulator. In order to improve the production of strains and optimize the culture conditions of fermentation, the strong constitutive promoter PoprL was selected to construct the recombinant strain CO by homologous recombination using the plasmid pUCP24/recTE in Pseudomonas syringae DC3000. The results showed that the productions of COR  increased in CO strain. The yield of CO strain was 1.8 times as much as that of the original strain under 18 ℃ culture and 4.1 times than under 28 ℃ culture. In this study, promoter substitution was used to effectively increase the yield of COR, and the restriction effect of high-temperature fermentation conditions on the yield of COR was improved, which provided strong support and reference for the strain modification and industrial production of COR.

Key words: coronatine, secondary metabolites, promoter, pseudomonas syringae

摘要： 冠菌素（coronatine, COR）是由多种丁香假单胞菌致病变种产生的次生代谢产物，是一种新型植物生长调节剂。为了提高菌株冠菌素产量并优化发酵培养条件，将来源于假单胞菌肽聚糖脂蛋白编码基因oprL高效表达组成型启动子PoprL，通过质粒pUCP24/recTE同源重组到丁香假单胞菌DC3000冠菌素合成基因cfl中，得到启动子重组菌株CO，在18和28 ℃培养条件下发酵培养，结果表明，CO菌株在18 ℃培养条件下冠菌素产量是出发菌株DC3000的1.8倍，在28 ℃培养条件下冠菌素产量是出发菌株DC3000的4.1倍。利用启动子替换的方法有效提高了冠菌素的产量，并且改善了高温发酵条件对菌株冠菌素产量的制约影响，为冠菌素的菌种改造和工业化生产应用提供有力支持与借鉴。

关键词: 冠菌素, 次生代谢产物, 启动子, 丁香假单胞菌