FSM encodes a putative ortholog of Arabidopsis FASCIATA1 (FAS1) that corresponds to the p150 subunit of chromatin assembly factor-1 (CAF-1). FSM is expressed patchily in tissues with actively dividing cells, suggesting a tight association of FSM with specific cell-cycle phases. Mutant fsm plants exhibited aberrant root cell lineages suggesting defects in RAM maintenance and cellular organization in roots, caused by a deregulation of cell?cycle progression and disorganization in the quiescent center (Abe et al., 2008).