Regulation of branching during inflorescence development in monocots.

Abstract The structure of the plant inflorescence is an important agronomic and ornamental trait studied for its potential economic applications: the capacity to modify inflorescence architecture has always been a breeder's goal. The shape of flowering plants is determined by the forms of the flower-bearing branch system, named inflorescences, and their position in the overall structure of the plant. Branching patterns and branches are produced by the shoot apical meristem; thus, inflorescence structure reflects the number, size and activity of the meristems. The genetic and molecular control of inflorescence and flower development has been extensively studied in model dicotyledonous plants such as Arabidopsis . However, not all the genes controlling inflorescence architecture in grasses are orthologous of Arabidopsis genes and thus grass inflorescence genes could not have been identified by simple extrapolation from Arabidopsis . Among plants, rice and maize in particular are the best genetic models for studying inflorescences: the maize inflorescence is a useful model for developmental and evolutionary studies, because several mutants have been isolated that taken together dissect every step of the inflorescence development. Because of the sequencing of the rice genome, positional information can be used to clone genes in maize, wheat and related grasses. In recent years, several master genes involved in inflorescence development have been cloned, providing considerable insights into the genetic control of the plant inflorescence.