Developmental and Structural Section
Dusak, Jill , Fisher, Roxanne .
Microsurgical Studies of the Auxin-mediated Control of Ceratopteris richardii Gametophyte Pattern Formation.
One of the most interesting topics in plant biology today is the evolution of developmental mechanisms. Scientists have greatly increased our understanding of Angiosperm plant development through the use of Arabidopsis and other higher plant model systems, however more information needs to be generated on the development of seedless plants in order to understand the evolution of plant developmental mechanisms. To fill this gap in our knowledge, we have been studying the auxin-mediated control of pattern formation in gametophytes of the fern Ceratopteris richardii. Auxin controls pattern formation in the gametophytes of the fern Ceratopteris richardii by controlling the initiation of the lateral meristem and the activity of both the apical and lateral meristems. The early growth of the gametophyte prothallus is due to the activity of an apical meristem, and on basal medium faster-growing gametophytes become female/hermaphrodites and secrete antheridiogen, a pheromone which causes slower-growing gametophytes to become males. The female/hermaphrodites generate a heart-shape by initiating a lateral meristem on either side of the prothallus and generating a second lobe. Male gametophytes do not initiate a lateral meristem, and thus have a strap-shaped prothallus. Our studies with auxins and auxin-regulating compounds show that exogenous auxin represses lateral meristem development, auxin is necessary for limiting the initiation of a lateral meristem to one side of the prothallus, and auxin polar transport is required for the proper timing of lateral meristem initiation. We are further investigating the relationship between the apical and lateral meristems through microsurgical studies and by adding point sources of auxin to gametophytes and sections of gametophytes.
Log in to add this item to your schedule
1 - Chatham College, Biology, Woodland Road, Pittsburgh, Pennsylvania, 15232, USA
Presentation Type: Poster
Location: Salon C, D & E - Gov Ballroom/Hilton
Date: Tuesday, August 16th, 2005
Time: 12:30 PM