title: The phylogeny of C/S1 bZIP transcription factors reveals a shared algal ancestry and the pre-angiosperm translational regulation of S1 transcripts.
abstract: Basic leucine zippers (bZIPs) form a large plant transcription factor family. C and S1 bZIP groups can heterodimerize, fulfilling crucial roles in seed development and stress response. S1 sequences also harbor a unique regulatory mechanism, termed Sucrose-Induced Repression of Translation (SIRT). The conservation of both C/S1 bZIP interactions and SIRT remains poorly characterized in non-model species, leaving their evolutionary origin uncertain and limiting crop research. In this work, we explored recently published plant sequencing data to establish a detailed phylogeny of C and S1 bZIPs, investigating their intertwined role in plant evolution, and the origin of SIRT. Our analyses clarified C and S1 bZIP orthology relationships in angiosperms, and identified S1 sequences in gymnosperms. We experimentally showed that the gymnosperm orthologs are regulated by SIRT, tracing back the origin of this unique regulatory mechanism to the ancestor of seed plants. Additionally, we discovered an earlier S ortholog in the charophyte algae Klebsormidium flaccidum, together with a C ortholog. This suggests that C and S groups originated by duplication from a single algal proto-C/S ancestor. Based on our observations, we propose a model wherein the C/S1 bZIP dimer network evolved in seed plants from pre-existing C/S bZIP interactions.
authors.affiliation: Theoretical Biology and Bioinformatics, Department of Biology, Faculty of Science, Utrecht University, Utrecht, The Netherlands.
authors.forename: Alessia
authors.initials: A
authors.lastname: Peviani
authors.affiliation: Molecular Plant Physiology, Institute of Environmental Biology, Utrecht University, Utrecht, The Netherlands.
authors.forename: Jeroen
authors.initials: J
authors.lastname: Lastdrager
authors.affiliation: Molecular Plant Physiology, Institute of Environmental Biology, Utrecht University, Utrecht, The Netherlands.|Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, Umeå, Sweden.
authors.forename: Johannes
authors.initials: J
authors.lastname: Hanson
authors.affiliation: Theoretical Biology and Bioinformatics, Department of Biology, Faculty of Science, Utrecht University, Utrecht, The Netherlands.
authors.forename: Berend
authors.initials: B
authors.lastname: Snel
mesh_terms: D000595:Amino Acid Sequence; D050976:Basic-Leucine Zipper Transcription Factors / Q000145:classification*; D017124:Conserved Sequence; D032462:Cycadopsida / Q000235:genetics; D056890:Eukaryota / Q000145:classification*; D020440:Gene Duplication; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017930:Genes, Reporter; D019684:Magnoliopsida / Q000235:genetics*; D016366:Open Reading Frames / Q000235:genetics; D010802:Phylogeny; D014176:Protein Biosynthesis / Q000187:drug effects / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012689:Sequence Homology, Nucleic Acid; D013395:Sucrose / Q000494:pharmacology
chemical_list: D050976:Basic-Leucine Zipper Transcription Factors; D012333:RNA, Messenger; D013395:Sucrose