How a plant's motor organ gets its identity

摘要

Because plants are immobile, many have evolved mechanisms that help them respond to a changing environment. Some plants contain a motor organ that drives circadian leaf movements: The leaves flatten to receive sun during the day and fold at night. Though motor organ anatomy has been well studied, the gene that specifies the identity of the motor organ during plant development remains unknown. Jianghua Chen et al. (pp. 11723-11728) isolated the causative gene from a mutant Medicago truncatula plant that cannot fold its leaves at night because it lacks a motor organ. Genetic tests suggested that the gene, designated ELP1, is normally expressed in primordial cells that give rise to the motor organ.