An intriguing problem confronting contemporary botanists is how evolutionary transformations in developmental programs occur and how they contribute to morphological diversification. This problem can be addressed with a variety of techniques and over a range of taxonomic levels. My research program will explore the relationship between specific changes in gene function and corresponding morphological discontinuities among major lineages of flowering plants. In particular, I will focus on the diversification of female reproductive structures, which have tremendous ecological and economic importance.

To address this problem, I'm characterizing changes in gene expression directly associated with transitions in carpel and ovule morphology. Presently, I'm studying orthologs of two genes, CRABS CLAW (CRC) and INNER NO OUTER (INO), both of which are members of the YABBY family of genes, recently discovered in Arabidopsis thaliana (Arabidopsis). In Arabidopsis, CRC and INO regulate dorsoventral patterning in carpels and asymmetric outgrowth of ovule outer integuments, respectively. Through comparative in situ hybridization, I'm determining changes in patterns of expression for orthologs of these genes in diverse angiosperm species having different numbers of integuments, dissimilar micropylar orientations, or differing degrees of synorganization between their carpels and other floral appendages. I'm also exploring the functional conservation of these genes through reciprocal transformations of orthologous genes into Arabidopsis, to determine whether they rescue mutant phenotypes. In the future, I'll expand my research program to include orthologs of additional genes that are integral to aspects of ovule and carpel development that vary among angiosperm lineages. Ultimately, I hope to assemble a general model that synthesizes available knowledge on the molecular-genetic basis of angiosperm gynoecial diversification.