During multicellular development, the specification of distinct cell fates is often regulated by the same transcription factors operating differently in distinct cis-regulatory modules. In the model plant Arabidopsis root, distinct cell types are determined by the interacting transcription factors within one contiguous tissue layer. Using fluorescence lifetime microscopy we revealacell type-specific protein complexes that differentially regulate target genes and instruct distinct cell fates. In addition to determining the network function in other organs, we are currently studying how are these complexes established and maintained by generating a temporal interaction map and dissecting the transcriptional regulation by these complexes.We will use the following tools: FRET-FLIM, confocal microscopy imaging, mutants analysis.​