Despite their genetic redundancy TRB genes in Arabidopsis show signs of specialization
TELOMERE REPEAT BINDING FACTORS (TRBs) in Arabidopsis thaliana have been linked to many functions that include telomere homeostasis, positive regulation of the expression of genes involved in protein biogenesis, recruitment of Polycomb Group Complex 2 to repress targets epigenetically and association with the PEAT complex that is associated with heterochromatin formation. We compared genome-wide binding of TRB paralogs TRB1,2 and 3 and characterized phenological and molecular phenotypes of stacked trb mutants, including transcriptome comparisons. Overall, TRBs play redundant roles; however, TRB1 function can be separated from TRB2/3 function. While the former binds to many sites located in open chromatin that are associated with robust gene expression, TRB2 and TRB3 show more restrictive binding that is more tightly linked to epigenetic repression.