Comparative analysis ofSQUAMOSA PROMOTER BINDING PROTEIN-LIKE (SPL)gene family between bryophytes and seed plants

Abstract

AbstractSQUAMOSA-PROMOTER BINDING PROTEIN-LIKE(SPL) genes encode plant-specific transcription factors which have been found to be conserved in green plants lineage. SPL proteins are important regulators of diverse plant developmental processes in bryophytes and vascular plants. In our study, we took advantage of available genome sequences of representatives of each bryophyte clade to investigate the relationships ofSPLgenes between bryophytes and model angiospermArabidopsis thaliana. We have identified fourSPLgenes in each of the two hornworts species,Anthoceros agrestisandAnthoceros punctatus, what is similar to the set ofSPLgenes present in the liverwortMarchantia polymorpha. Thus, the analyzed hornworts and liverwort genomes encode a minimal set ofSPLgenes in comparison to other land plants that may resemble an archetype ofSPLgenes present in the ancestor of land plants. The phylogenetic analysis revealed the presence of fourSPLgroups. Comparative gene structure analysis showed thatSPLsshare similar exon-intron organization within the same phylogenetic group with some exceptions in hornworts. While we have identified conserved protein motifs between bryophytes andArabidopsisin three out of four phylogenetic groups, the motif content differed explicitly in the fourth group. Since current understanding ofSPLgenes mostly arises from seed plants, the presented comparative and phylogenetic analysis will provide better understanding ofSPLgene family from the representatives of the oldest living land plants.