XVI International Botanical Congess

In plants, phytoene synthase (PSY), phytoene desaturase (PDS) and zetacarotene desaturase (ZDS) can be considered as the early carotenogenic enzymes. We have isolated these cDNAs from yellow petals of gentian (Gentiana lutea). Each gene comprises a multigene family by Southern blot analysis. The higher expression of PSY and PDS genes was found in flowers, but not detectable in leaves and stems by Northern blot analysis. The expression of ZDS gene was higher in flowers, and lower in leaves, but not detected in stems. Analyses of PSY, PDS and ZDS gene expression in petals revealed that the levels of these gene transcripts were lowest in young buds, and highest in fully open flowers, which is in parallel to carotenoid content. The transcription of these genes may control carotenoid accumulation during flower development of gentian.