BZIP TRANSCRIPTION FACTOR THAT CONTROLS EXPRESSION OF THE STORAGE PROTEIN IN THE RICE PLANT

摘要

cDNAs (RISBZ1, RISBZ4, and RISBZ5) encoding bZIPtranscription factors were isolated from a cDNA library originatingin rice plant seed. The cDNAs encode novel proteins and have bindingactivity to the GCN4 motif. Among them, RISBZ1 activatedtranscription mediated by the GCN4 motif by 100-fold or more. Sincethe expression of RISBZ1 precedes the expression of a seed storageprotein gene and is expressed only in maturing seeds, it is suggestedthat RISBZ1 controls the expression of rice seed storage proteins.In addition, by linking the recognition sequence of thetranscription factor, the GCN4 motif, in tandem and introducing itinto the promoter for a gene encoding seed storage protein tofacilitate its binding to the transcription factor RISBZ1,expression of a foreign gene under the control of the modifiedpromoters is greatly enhanced.