Abstract: Eight clones were isolated from maize ( Zea mays L. ) λgt11 cDNA expression library using 5' upstream regulatory sequence of DC59 as the probe and screened from carrot somatic embryo cultures. Interaction assays were performed using the systematic deletion fragments of 5' upstream regulatory sequence and the expressed proteins of each clone and gel retardation assay and the competitive binding tests were carried out. The results indicated that protein Gl0 expressed from the corresponding clone Gl0 was able to bind at - 295 to - 221 bp of the regulatory sequence specifically. This region contains a pair of direct and inverted repeats GGAA and GGAA as well as GGAA and TTCC, respectively, and a putative plant hormone abscisic-acid responsive element ACGTGG. Predicted secondary structure demonstrated that protein Gl0 encompassed DNA binding domains. This is further borne out by sequence homology comparison with other known transcription factors. So the clone Gl0 possesses several properties as a new trans-acting factor gene related to embryospecific genes.

Key words: DC59, 5' upstream regulatory sequence, Maize' s cDNA expression library, Transacting factor