A VEL3 histone deacetylase complex establishes a maternal epigenetic state controlling progeny seed dormancy

Mother plants play an important role in the control of dormancy and dispersal characters of their progeny. In Arabidopsis seed dormancy is imposed by the embryo-surrounding tissues of the endosperm and seed coat. Here we show that VERNALIZATION5/VIN3-LIKE 3 (VEL3) maintains maternal control over progeny seed dormancy. Acting early in endosperm development, it establishes an epigenetic state that primes the depth of primary seed dormancy that will be reached later during seed maturation. VEL3 relocates MSI1 to the nucleolus and associates with other components of the histone deacetylase complex (HDAC). Furthermore VEL3 preferentially associates with pericentromeric chromatin and is required for deacetylation and H3K27me3 deposition in the central cell. Interestingly, the epigenetic state established by the maternal VEL3 is retained in mature seeds, and controls seed dormancy in part through the repression of programmed cell death-associated gene ORE1. Our data demonstrates a novel mechanism by which maternal control of progeny seed physiology persists post-shedding, maintaining parental control of seed behaviour.