Recent progress has been made in identifying the genes that play key roles in regulating plant development. In deaf development and vivipary in maize, flower organ specification in Arabidopsis and Antirrhinum, and trichome formation in Arabidopsis analysis of the genes at the molecular level has provided an indication of the probable function of the gene products. In other developmental systems including embryogenesis, root hair formation and root morphogenesis, genetic pathways have been elucidated and the cloning of the genes is expected in the near future. © 1992.