Abstract
It is considered that there is a factor in white petals of chrysanthemum that inhibits accumulation of carotenoid. We performed PCR-select subtraction screening, searched for cDNAs that are deferentially expressed in white petals, and obtained a clone expressed specifically in white petals. The nucleotide sequence of the clone is highly homologous to carotenoid cleavage dioxygenase (designated CmCCD1). All the white petals tested showed high levels of expression of CmCCD1, while the transcripts in yellow petals were under detection level. Expression of CmCCD1 was strictly limited to flower petals and very low level of expression was observed in stems and leaves. We also analyze expression of genes for carotenoid biosynthesis, and found that there were no significant difference in the level of expression of those genes between white and yellow petals. It is therefore considered that, in white petals, carotenoid degradation causes white color although carotenoid biosynthesis takes place.
