Abstract
Time of flower-opening in Pharbitis nil st. Violet is controlled by endogenous rhythm, the phase of which is rapidly reset by a light-off signal and temperature. We have revealed that actin organization is one of the essential factors of this phenomenon. Plants encode at least two ancient and divergent classes of actin, vegetative and reproductive, and each class produces several subclasses of actin isovariants. We identified nine actin genes from EST-database of morning glory floral organ. These actin genes exhibited 88-99% amino acid similarity and were classified into three of vegetative-class and six of reproductive-class. These nine actin genes displayed different patterns of transcript accumulation in petals during flower-bud development and flower opening. We are now investigating the expression pattern of the nine actin genes in the petal more detail in order to discuss the actin function on flower-opening in P. nil.
