A continuous gene expression profiling of roots was performed during daytime at regular interval from transplanting until harvesting to characterize the transcriptional and physiological changes in the root system of rice throughout the entire growth under natural field conditions. Overall design: Roots were sampled at daytime (12:00) at 7-day intervals encompassing 14 different growth stages. All samples were obtained from rice plants grown in the field during the 2008 cultivation season.