Abstract Detail

Discerning homologies: Gene expression, development, and morphology

Sinha, Neelima [2], Goliber, Tom [2], Kessler, Sharon [2], Kim, Minsung [2], Champagne, Connie [2], Geeta, R [1], Chung, Kook-Hyun [2].

The Development and Evolution of Leaves.

The Class I Knotted-like homeobox (KNOX 1) genes are highly expressed in the shoot apical meristem but not expressed in the emerging leaf primordium in tobacco, maize, or Arabidopsis. In tomato, KNOX1 expression (LeT6, TKN1) is seen in the early leaf primordium (Chen et al. 1997; Hareven et al. 1996). We have analyzed compound leaf producing shoot apices in clades with independently derived compound leaves and shown that with one exception (a derived clade in the Fabaceae) compound leaves always show expression of KNOX genes (Bharathan et al., 2002). In the derived pea clade the LFY/FLO gene regulates this function of generating leaf complexity. While KNOX genes appear to be important for generating leaf complexity (except in a derived clade in the Fabaceae) we find that other genes like PHANTASTICA might play a role in determining the form of the compound leaf generated. Transgenic plants overexpressing antisense PHAN suggest that PHAN, by modulating dorsiventrality, has a role in regulating the number of leaflets and their placement in a compound leaf. In Neobeckia aquatica, leaves with different morphologies are produced depending on environmental conditions. The expression differences between these two phenotypic states are also being explored.

1 - State University of New York, Ecology and Evolution, 640 Life Sciences Building, Stony Brook, New York, 11794-5245, USA
2 - University of California, Davis, Section of Plant Biology, 1 Shields Avenue, Davis, California, 95616

Keywords:
KNOX genes
compound leaves
PHAN
Evolution.

Presentation Type: Symposium
Session: 14-5
Location: Ballroom 1 (Cliff Lodge)
Date: Monday, August 2nd, 2004
Time: 2:45 PM
Abstract ID:899