Component of the Mediator complex, a coactivator involved in the regulated transcription of nearly all RNA polymerase II-dependent genes. Mediator functions as a bridge to convey information from gene-specific regulatory proteins to the basal RNA polymerase II transcription machinery. The Mediator complex, having a compact conformation in its free form, is recruited to promoters by direct interactions with regulatory proteins and serves for the assembly of a functional pre-initiation complex with RNA polymerase II and the general transcription factors. Involved in the regulation of histone H3 lysine tri-methylation (H3K36me3). Associates with the promoter, coding and terminator regions of target genes suggesting its function in transcription initiation, elongation and termination. Multifunctional protein which regulates plant immunity, especially during necrotrophic fungal infection (e.g. B.cinerea and A.brassicicola), flowering time and responses to hormones (e.g. abscisic acid ABA and ethylene) through interactions with distinct transcription factors