Transcription factor that specifically binds AT-rich DNA sequences related to the nuclear matrix attachment regions (MARs) (PubMed:17971039, PubMed:19517252). Negatively regulates plant innate immunity (PTI) to pathogens through the down-regulation of the PAMP-triggered FRK1 expression (PubMed:20738724). Acts redundantly with AHL18, AHL22 and AHL29 in the regulation of flowering and regulation of the hypocotyl elongation (PubMed:19517252). Acts as a chromatin remodeling factor that negatively regulates the leaf senescence (PubMed:17971039). Acts redundantly with AHL29/SOB3 to modulate hypocotyl growth inhibition in response to light (PubMed:18088311). Homodimer. Interacts with AHL12, AHL25, AHL29, TCP4, TCP13, EF114, ATAF2/NAC081, histone H2B.1, histone H3.3 and histone H4. Expressed in the hypocotyl and the vascular tissue of seedling. The PPC domain mediates interactions between AHL proteins. AHL27 and AHL29 double mutant exhibit a long hypocotyl phenotype in the light. Overexpression of AHL27 results in a decreased flg22-induced expression of FRK1 (PubMed:20738724). Overexpression causes also delay of leaf senescence, late flowering and modified leaf development (PubMed:10759496, PubMed:17971039).