Transcription factor that specifically binds AT-rich DNA sequences related to the nuclear matrix attachment regions (MARs). Binds an AT-rich DNA sequences in the FLOWERING LOCUS T (FT) promoter (PubMed:22442143). Acts redundantly with AHL18, AHL27 and AHL29 in the regulation of flowering and regulation of the hypocotyl elongation. Plays a role in both photo- and skotomorphogenesis (PubMed:19517252). Acts as a chromatin remodeling factor that modifies the architecture of FLOWERING LOCUS T (FT) chromatin by modulating both H3 acetylation and methylation leading to the regulation of FT expression during flowering induction (PubMed:22442143). Homodimer. Interacts with HDA1/HDA19, HDA6 AND HDA9. Expressed at the hypocotyl-root transition zone and the root hair zone. Also detected in the inflorescence. Highly expressed in earlier growth stages in hypocotyls, roots and the vascular bundles of the leaves. Detected later in the vascular bundles of the basal leaves aera. The PPC domain mediates interactions between AHL proteins. Slightly longer hypocotyls. Overexpression of AHL22 results in delayed flowering and inhibition of hypocotyl growth.