Abstract
Pharbitis (Ipomoea) nil cv. Violet is an ideal plant for the study of photoperiodic induction of flowering because seedling of Violet can be induced to flower by the single short-day treatment. We examined the changes in gene expression in cotyledon during the flower-inductive photoperiod and identified several genes that can be the candidates of so-called flowering genes. One of them, PnC401 has been intensively characterized. The database search now revealed that it encodes the pentatricopeptide repeat protein (PPR). There are more than 450 members of the PPR protein family in Arabidopsis genome. Among them, PnC401 and related proteins constitute a distinct group. In Arabidopsis, there are two C401 related proteins and the one, AtC401 can interact with CONSTANS, the regulator of the photoperiodic induction of flowering in Arabidopsis. We will present comparative studies of these genes of Pharbitis and Arabidopsis and discuss the photoperiodic induction of flowering in Pharbitis.
