The photoperiodic control of flowering in rice, a short-day plant

Abstract

Regulation of flowering is one of the most important processes of plants since it is closely related to the success of reproduction. Flowering time is controlled by a number of environmental factors such as day length, temperature, and water supply. Among them, the photoperiod is a key regulator of flowering and has been studied for many years (Figure 1). However, molecular genetic study of the photoperiodic regulation of flowering began only about 10 years ago. Arabidopsis thaliana, a long-day plant, has been extensively used to study the photoperiodic regulation of flowering, and a large number of genes involved in flowering time determination have been isolated and characterized. As a result we now understand the genes involved in day length control of flowering in a long-day plant relatively well. However, our knowledge on genes involved in flowering in short-day plants has been limited mainly because many model short-day plants have not been amenable to molecular genetic analysis until recently.