ZANIS, MICHAEL J.1*, DOUGLAS E. SOLTIS2, and PAMELA S. SOLTIS3. 1School of Biological Sciences, Washington State University, Pullman, WA 99164, USA; 2Department of Botany and the Genetics Institute, University of Florida, Gainesville, FL 32611, USA; 3Florida Museum of Natural History and the Genetics Institute, University of Florida, Gainesville, FL 32611, USA. - Isolation and characterization of floral MADS Box genes from Nuphar and Illicium.
The ABC model of floral organ development proposes combinatorial
interaction of A, B, and C class genes whereby these three classes of
genes specifies the four floral organs, sepals, petals, stamens, and
carpels. A class genes specify sepal identity, A plus B class genes
specify petal identity, B plus C class genes specify stamen identity,
and C class genes specify carpel identity. Many of the genes involved
in the ABC model are members of the MADS box gene family. The ABC
model has been primarily characterized in Arabidopsis and
Antirrhinum. Significantly, the B and C functions of this model
also extend to maize (Zea), although functional conservation of
the A function remains to be demonstrated. Nevertheless, the strong
genetic and molecular evidence for the conservation of at least
portions of the ABC model suggests that this is an ancient regulatory
network, perhaps applicable to most angiosperms. However, various
modifications of the specific components of the ABC model may have
occurred in different lineages of angiosperms. We have developed a
protocol that permits the extraction of quality RNA from small amounts
of tissue from a wide range of angiosperms. Using this approach, we
have extracted RNA from young flowers, as well as floral organs at
various stages of development from the basal angiosperms Nuphar
(Nymphaeaceae) and Illicium (Illiciaceae). We have isolated
MADS-box genes from Nuphar and Illicium and present
phylogenetic analyses as well as preliminary expression analyses of
these genes.
Key words: ABC model, basal angiosperms, MADS-box genes, RNA isolation