The isolation, molecular characterization and expression of dihydroflavonol 4-reductase cDNA in the orchid, Bromheadia finlaysoniana

Abstract

The cDNA, ODFR, encoding dihydroflavonol 4-reductase (DFR) was isolated from a cDNA library constructed from Bromheadia finlaysoniana flowers using a homologous probe generated via PCR. Southern blot analysis suggests that DFR is represented by a single gene in this orchid while Northern blot and reverse transcriptase-PCR analysis showed that DFR is expressed in all purple colored tissues. A phylogenetic tree constructed based on multiple alignments among DFR sequences showed that the DFR genes isolated from barley, maize and B. finlaysoniana, which are all monocotyledons, are more similar to each other than to DFR sequences from dicotyledonous plants.