Identification of LEC1 target genes

The transcription factor (TF) LEAFY COTYLEDON1 (LEC1) acts as an essential regulator of Arabidopsis embryogenesis and seed development. It controls aspects of early embryogenesis such as cotyledon identity and suspensor morphology, as well as seed maturation processes such as storage compound accumulation, acquisition of desiccation tolerance and dormancy. To identify downstream components of the LEC1 regulon, dexamethasone-regulated expression of LEC1 and ChIP/chip were applied and revealed the enrichment of phytohormone- as well as elongation-related genes among LEC1 target genes. Two weeks old 35S::LEC1::GR seedlings were treated with DEX or ethanol for 24 hours before cross-linking and chromatin isolation. Four biological replicates were performed, using an ethanol-treated sample as control (LEC1_EtOH versus LEC1_DEX). After data normalization, statistical analysis and exclusion of putative false negatives, a number of 356 target promoter regions were identified.