Use of the β-Glucuronidase (GUS) Reporter System to Localize Promoter Activities of the Endogenous Plant Calpain DEFECTIVE KERNEL1 (DEK1)

: The DEFECTIVE KERNEL1 (DEK1) gene encodes the unique plant calpain protein, which is fundamental for cell specification, development, and growth of land plants. The β-glucuronidase (GUS) reporter gene system has been used to characterize and localize gene expression over several decades. When cloning a promoter upstream of the uidA/GUS reporter gene, you visualize when the promoter is activating expression by monitoring enzymatic activity of GUS, by detecting β-glucuronidase cleavage products. Here we describe a protocol for monitoring the DEK1 promoter activity in different tissues in Arabidopsis by GUS staining.