A suppressor of axillary meristem maturation promotes longevity in flowering plants

Abstract Post embryonic development and growth of flowering plants are for a large part determined by the activity and maturation state of stem cell niches formed in the axils of leaves, the so-called axillary meristems (AMs)1,2. Here we identify a new role for the Arabidopsis AT-HOOK MOTIF CONTAINING NUCLEAR LOCALIZED 15 (AHL15) gene as a suppressor of AM maturation. Loss of AHL15 function accelerates AM maturation, whereas ectopic expression of AHL15 suppresses AM maturation and promotes longevity in Arabidopsis and tobacco. Together our results indicate that AHL15 expression acts as a key molecular switch, directly downstream of flowering genes (SOC1, FUL) and upstream of GA biosynthesis, in extending the plants lifespan by suppressing AM maturation.