Transcriptional circuitry underlying seed coat development in Arabidopsis

Abstract

We analyzed two sub-regions of the maternal seed coat, chalazal (CZSC) and distal (SC), using transcriptomic and histological analyses in the model plant Arabidopsis thaliana. Hierarchical clustering analysis showed that the CZSC and SC are transcriptionally distinct, though the two sub-regions are more similar during early stages of seed development. Robust statistical and network analysis revealed novel roles for both sub-regions during the course of the seed lifecycle and provides insight into the regulatory circuitry underlying these poorly studied sub-regions of the seed. Data show many of the processes that characterize the SC including starch deposition during the morphogenesis phase, and mucilage deposition and cell wall thickening during the maturation phase, are either absent or expressed to a much lesser extent in the CZSC. We further analyzed the CZSC in detail and show that this sub-region is likely involved in the control of information into the seed from the maternal plant and that some of these processes are predicted to operate through the activity of bZIP transcription factors through the G-box DNA sequence motif.