biostudies-literatureUnknownDing XLeaf senescence is a highly-programmed developmental process during the plant life cycle. ABA plays an important role in leaf senescence. However, the mechanism underlying ABA-mediated leaf senescence, particularly the upstream epigenetic regulatory network, remains largely unclear. Here, we identified that SlJMJ4, a Jumonji C (jmjC) domain-containing protein in tomato, specifically demethylates di- and tri-methylations of lysine 27 of histone H3 (H3K27) in vitro and in vivo. Overexpression of SlJMJ4 results in premature senescence phenotype and promotes dark- and ABA-induced leaf senescence in tomato. Under dark condition, SlJMJ4-promoted leaf senescence is associated with upregulated expression of transcription factors (SlORE1 and SlNAP2) and senescence-associated genes (SlSAG113, SlSAG1Horticulture researchuhab077https://www.ebi.ac.uk/biostudies/studies/S-EPMC8973004biostudies-literatureHistone H3K27 demethylase SlJMJ4 promotes dark- and ABA- induced leaf senescence in tomato.PMC8973004Gu DJiang YDing XZhang DLi ZLiang HZhu HDuan XfalseHistone H3K27 demethylase SlJMJ4 promotes dark- and ABA- induced leaf senescence in tomato.Leaf senescence is a highly-programmed developmental process during the plant life cycle. ABA plays an important role in leaf senescence. However, the mechanism underlying ABA-mediated leaf senescence, particularly the upstream epigenetic regulatory network, remains largely unclear. Here, we identified that SlJMJ4, a Jumonji C (jmjC) domain-containing protein in tomato, specifically demethylates di- and tri-methylations of lysine 27 of histone H3 (H3K27) in vitro and in vivo. Overexpression of SlJMJ4 results in premature senescence phenotype and promotes dark- and ABA-induced leaf senescence in tomato. Under dark condition, SlJMJ4-promoted leaf senescence is associated with upregulated expression of transcription factors (SlORE1 and SlNAP2) and senescence-associated genes (SlSAG113, SlSAG12022-01-01T00:00:00Z2022 Jan2026-04-07T13:20:26.001Z2025-04-05T22:18:27.126ZS-EPMC89730043504320710.1093/hr/uhab077