Circadian clock controlled gene expression in soybean seeds

Microarray expression profiling was used to identify genes expressed in developing soybean (Glycine max) seeds that are controlled by the circadian clock. Plants with developing seeds were entrained to 12hour light: 12 hour dark cycles and sampled in constant light conditions. Soybean seeds entrained to 12 hour-light:12 hour dark photocycles were harvested after 24 hours of constant light and temperature conditions. Timepoint 24h represents subjective dawn. To minimize developmental variation, flowers were marked as they opened and seeds were harvested from marked pods after 5 weeks. There are two replicate samples at each time point, and each sample consists of 8 seeds collected from three diffferent plants.