Chromatin remodeling factor. Acts as a 'reader' protein by binding to H3K36me3 and H3K36me3 to control histone H4 acetylation. Increases the transcriptional levels of the flowering time genes FLC and FT (PubMed:25183522, PubMed:25211338). Binds the chromatin at the FT promoter upon interaction with CO (Probable). Interacts with HAM1 and HAM2 (PubMed:25183522). Interacts (via MRG domain) with CO (Probable). Component of the NuA4 histone acetyltransferase complex (Ref.7). Localized only in the euchromatic regions. Ubiquitous. Mainly expressed in the vasculature of cotyledons and leaves, and in roots and inflorescences (PubMed:25211338). No visible phenotype, due to the redundancy with MRG2. Mrg1 and mrg2 double mutants are late-flowering under long-day growth conditions.