The Cotton Transcription Factor Gawrky1 Gossypol Biosynthetic Pathway Key Enzyme Gene Cad1-a Transcriptional Regulation

CAD1 is the cotton (+)-(-Cadinene synthase encoded by a gene family. CAD1-A is one of the members of the family, which could be induced by the fungal elicitor. The previous work showed that the promoter driven the expression of GUS mainly in the tip of the root, particularly in the lateral roots and vascular tissues. The transcription start site (TSS) of CAD1-A was located at the 108 base upstream the translation start codon (ATG). To clarify the cis-elements responsible for the tissues-specific and inducible expression pattern of the CAD1-A, we examined the expression pattern in transgenic tobaccos with a 5' deletion in the promoter region of CAD1-A. The histochemical and quantitative enzyme assay showed that the 197 bp promoter upstream the TSS already had a basal transcription activity. 5'deletion assay also suggested that cis-elements, which resided in a region between -504 bp and -310 bp might play a role in the transcriptional activity of the CAD1-A promoter induced by flooding stress or fungal elicitor.