Abscisic acid and seed development in a lady’s slipper orchid

Although abscisic acid (ABA) is commonly recognized as a primary cause of seed dormancy, there is a little information on its role during orchid seed development. Lee et al. study the dynamic changes of endogenous ABA concentration and distribution during seed development of Cypripedium formosanum and find that it serves as the key inhibitor of germination. A distinct accumulation pattern of ABA suggests that it is synthesized in the cytosol of embryo cells during the early stages of seed development, and is then exported to the apoplastic region of the cells for subsequent regulatory processes as seeds approach maturity.