Abstract: Plant demethylase ROS1 was an important factor in epigenetic regulation. It could activate the expression of genes and was closely related to the processes of plant development and various stress responses. In this study， AtROS1 gene from Arabidopsis thaliana was used as the target gene， and ‘digestionligation method was applied for constructing plant expression vector pER8ROS1 which could be induced by 17βestradiol. Then the vector was transferred to Agrobacterium tumefaciens LBA4404， and the inducible expression characteristics were verified by the transient expression system of Nicotiana tabacum. The results of qPCR showed that 17βestradiol could effectively induce the expression of the target gene in pER8ROS1 and the optimal concentration of 17βestradiol was 50 to 100 μmol·L-1. The expression level of ROS1 gene gradually increased and reached the highest level at 12 h. The construction of pER8ROS1 laid a good foundation for the epigenetic mechanism study in plant environmental stress.

Key words: pER8ROS1, 17βestradiol, chemicalinducible expression vector, transient expression