Abstract: Coronatine (COR) is a new plant growth regulator, which can effectively regulate plant growth and enhance plant stress resistance. At present, coronatine is mainly obtained by fermentation of microbial strains, but the low yield of strains is the main problem limiting the application of coronatine. To develop high-yield strains of coronatine, the RecTE genetic recombination system was used to knockout hrpS gene in model strain Pseudomonas syingae pv. tomato DC3000, and the mutant strain H1-20 was selected from transformants. After fermentation culture for H1-20, the result showed that the coronatine production of H1-20 reached 22.67 mg/L, which was 2.36 times to Pst DC3000. In this study, engineering strains were successfully constructed by the application of RecTE recombination system, which provided more options for coronatine producing strains and laid a foundation for further development of high-yielding strains of coronatine.