Studies on Carotenoids in the Petals of Compositae Plants

Abstract

Carotenoids are one of the most important pigments for petal coloration in the yellow to red range; however, knowledge of carotenoids in petals is relatively limited. To better understand flower carotenoids, we analyzed carotenoid composition, the expression of carotenogenic genes, and the relationship between pigment composition and petal color in petals of Compositae plants, including chrysanthemums. We found that petals of yellow-flowered chrysanthemums have a unique carotenoid composition, and that the formation of white petal color in chrysanthemums involves carotenoid degradation catalyzed by carotenoid cleavage dioxygenase (CmCCD4a). We also showed three routes to an orange petal color via carotenoid components in 9 Compositae plants. In addition, we identified (5Z)-carotenoids that contribute orange color formation in calendula petals. In this review, we summarize our studies on carotenoids in the petals of Compositae plants.