The study characterizes the distinct and overlapping roles of the rice PI paralogs OsMADS2 and OsMADS4 in lodicule specification, flowering time, and floral organ development by analyzing null and double mutants and overexpression lines. Genome-wide binding (ChIP‑seq) and transcriptome (RNA‑seq) analyses identified downstream targets involved in cell division, cell wall remodeling, and osmotic regulation that underpin the observed phenotypes. These findings reveal novel functions for PI paralogs in reproductive development and highlight mechanisms of transcription factor diversification in Oryza sativa.

The study shows that silencing of NOR2 rRNA genes in Arabidopsis thaliana depends primarily on CHH-context cytosine methylation, particularly mediated by CMT2 and the chromatin remodeler DDM1, rather than CG or CHG methylation. Comparative promoter analysis revealed a prevalence of CHH sites in plant rDNA promoters, explaining why CHH methylation mutants disrupt NOR2 silencing more strongly, while NOR2 loci are hyper‑methylated and more condensed than NOR4.