Coconut foliar decay virus (CFDV) is a small single-stranded DNA virus which is limited to phloem tissues of coconut palm. A viral promoter has been identified which, if stably transformed into tobacco in fusion with GUS, shows GUS activity confined to the primary and secondary phloem tissue. I propose to map the phloem-specific regulatory elements in the promoter region by site- directed mutagenesis followed by in situ localization of GUS activity in transformed tobacco. This work will be completed by foot-printing and mobility-shift experiments with tobacco nuclear protein extracts to identify protein-binding regions within the promoter. These regions will be used as probes to screen a tobacco expression library for the corresponding proteins.