On the evolution of the transcription factors ARABIDOPSIS BSISTER and JAGGED with an emphasis on their transcriptional regulation

ARABIDOPSIS BSISTER and JAGGED are highly conserved transcription factors. ARABIDOPSIS BSISTER is involved ovule and seed development including the degeneration of the nucellus during endosperm formation while JAGGED regulates boundary formation and growth of lateral organs during vegetative and generative growth. Both transcription factors are, with few exceptions, one or two copy genes and were shown to have largely conserved functions and expression patterns in a broad range of flowering plants. Their cis-sided evolution, however, is underexplored. In Roessner et al. 2023 we identified transcription factor binding sites upstream the transcription start site of different crucifer orthologs of ARABIDOPSIS BSISTER and investigated their activity in an Arabidopsis background. In Roessner et al. 2024 we proposed a phylogenetic framework of JAGGED and other closely related transcription factors, laying the foundation for further studies. This work, next to giving an overview on the evolution of ARABIDOPSIS BSISTER, aims to connect function, expression patterns and cis-sided regulation. Additional data will be presented that show a high conservation of regulatory motifs related to epigenetic silencing in the putative regulatory sequences of ARABIDOPSIS BSISTER and JAGGED. This work will help our understanding of how an invariant genome can encode for many different tissues and complex organs like flowers.