Involved in pre-mRNA splicing. Plays a role during development in processes such as meristem maintenance, leaf morphogenesis and root morphogenesis. ATP + H2O = ADP + H(+) + phosphate Widely expressed but spatially and temporally regulated during development. Defects in female gametophyte development. Belongs to the DEAD box helicase family. DEAH subfamily. PRP22 sub-subfamily.