Abstract:ApY2SK2 a dehydrin gene from Agapanthus praecox was identified to have the positive protective effect on embryonic cells during cryopreservation. In order to reveal the regulatory mechanism of ApY2SK2 response to complex stresses of cryopreservation, a 1 200 bp promoter sequence of ApY2SK2 was cloned and analyzed by using Chromosome Walking technique. The results showed that: (1) ApY2SK2 promoter contained multiple stress, hormones response and plant embryo developmentrelated cisacting elements. Quantitative Realtime PCR assay suggested that the ApY2SK2 promoter had tissuespecific expression pattern, and ApY2SK2 gene had the highest expression level in the leaves and fruits of A. praecox. This gene was significantly upregulated response to various stress and ABA treatments. (2) Five different deletion fragments of ApY2SK2 promoter were constructed into pBI121 expression vectors, and using Agrobacterium mediated transformation and PCR identification to obtain the A. thaliana T3 generation transgenic lines. (3) GUS histochemical staining results showed that GUS staining signal were mainly distribute at the whole seedling, and the leaves, flowers and mature fruits of adult transgenic plants. Furthermore, gene transient transformation in leaf epidermis of tobacco test showed that the driver activity of 5 different deletion promoter fragments were significantly different under PEG and ABA treatments. (4) Quantitative determination of GUS enzyme activity suggested that MBS element and ABRE element of the ApY2SK2 promoter involved in response to drought and osmotic signals, respectively. The LTR element participates in the low temperature response. Additionally, -1 199 to -262 bp of ApY2SK2 promoter contained multiple tandem ABRE cisacting regulators (locate at -373 to -211 bp) that play an important role in response to ABA signaling. This study finally confirmed that ApY2SK2 promoter has tissue specific regulatory functions, and some core cisacting elements play a decisive role in regulating the ApY2SK2 response to different stresses and hormone signals.