The YPEL gene CELL DIVISION SUPPRESSOR negatively regulates cell division in plants

The CELL DIVISION SUPPRESSOR (CDS) gene encodes a conserved YPEL-family zinc-finger protein whose biological role in plants has remained largely uncharacterized. Here, we characterized the Arabidopsis CDS gene and demonstrated that its protein contains a conserved metal-binding motif and a canonical nuclear localization sequence shared across YPEL proteins. Although CDS mRNA is constitutively expressed in all tissues, promoter-reporter analyses revealed that CDS protein accumulates only weakly and is absent in meristematic cells, suggesting strong posttranscriptional regulation. Overexpression of CDS (35S::CDS) caused severe growth inhibition, disrupted root meristem organization, reduced cell number, enlarged cell size, and decreased CYCB1;1 activity, indicating that elevated CDS suppresses mitotic progression and promotes entry into the endocycle. A Phalaenopsis ortholog, PaCDS, displayed similar expression patterns and recapitulated the Arabidopsis overexpression phenotypes, demonstrating evolutionary conservation of CDS function across monocots and dicots. Subcellular localization analysis showed that CDS enters the nucleus specifically in dividing cells and associates with DNA during mitosis. Together, these findings reveal CDS as a conserved negative regulator of cell division that modulates meristem activity by repressing the mitotic cell cycle and promoting endocycle initiation. This work uncovers a previously unrecognized role of YPEL-family proteins in plant cell cycle control and provides a foundation for manipulating growth and organ development across species.