Jill Preston

Edinburgh, Scotland

PhD Student - University of Missouri, St Louis, USA

MSc Plant Genetic Manipulation - University of Nottingham, UK

BSc Biological Sciences - Napier University of Edinburgh, UK

Research Interests:

I am interested in the evolution of genes that affect floral development in the grass family (Poaceae). This family comprises around 10,000 species, encompassing several of the world’s most important crops, such as maize, rice, and wheat. The basic unit of the grass inflorescence is the spikelet: a flower-containing structure that is unique within the angiosperms. Spikelets and grass flowers (florets) show considerable morphological variation across the family, giving rise to questions about homology between structures and the genetic controls that determine their development. Many of the genes responsible for normal inflorescence development belong to the MADS box family of transcription factors, including the ABC genes initially characterized in Arabidopsis (Brassicaceae). In the ABC model of floral development, A class genes determine identity of sepals and petals, B class genes petals and stamens, and C class genes stamens and carpels. Although this model has traditionally been extrapolated to all angiosperm families, growing evidence questions the functional conservation of the genes involved, making them good candidates for elucidating the evolution of floral form.

Current Research:

The focus of my research is to determine the molecular evolution of the Arabidopsis APETALA1-FRUITFULL (A class) gene homologues in grasses (and close relatives), with the ultimate aim of understanding how evolution of these genes have impacted inflorescence form. By comparing patterns of AP1-FUL gene expression across the family I am testing specific hypotheses about the neo-functionalization of grass AP1-FUL genes in terms of how they interact with other transcription factors to determine the identity, timing, and/or order of particular developmental events. My second objective is to use a combined approach, based on both expression analyses and studies of developmental morphology, to elucidate the role of AP1-FUL homologues in the evolution of the grass spikelet from the more typical monocot flower, represented by their closest relative Joinvillea.

Using the well-supported grass phylogeny to direct my sampling, I am currently amplifying AP1-FUL homologues from each of the main subfamilies in order to: (1) determine the history of gene duplications within the family, (2) generate probes for in situ hybridization gene expression studies, and (3) produce the data required for testing hypotheses of selection and gene regulation. By taking an integrated approach based on phylogenetic relationships, patterns of gene expression, and developmental morphology I hope to acquire a better understanding of how grasses have evolved their great diversity of form through changes at the molecular and developmental level.

Publications:

Atkins, H., Preston, J. and Cronk, Q. C. B. (2001) A molecular test of Huxley's line: Cyrtandra (Gesneriaceae) in Borneo and the Philippines. Biological Journal of the Linnean Society. 72(1). 143-159.

Bateman, R. M., Hollingsworth, P. M., Preston, J., Yi-Bo, L., Pridgeon, A. M. and Chase, M. W. (2003) Molecular phylogenetics and evolution of Orchidinae and selected Habenariinae (Orchidaceae). Botanical Journal of the Linnean Society. 142(1). 1-40.

Harris, D. J., Poulsen, A. D., Frimodt-Moller, C., Preston, J., and Cronk, Q. C. B. (2000) Rapid radiation in Aframomum (Zingiberaceae): Evidence from nuclear ribosomal DNA internal transcribed spacer (ITS) sequences. Edinburgh Journal of Botany. 57(3). 377-395.

Long, D. G., Moller, M. and Preston, J. (2000) Phylogenetic relationships of Asterella (Aytoniaceae, Marchantiopsida) inferred from chloroplast DNA sequences. Bryologist. 103(4). 625-644.

Pennington, R. T., Lavin, M., Ireland, H., Klitgaard, B., Preston, J., and Hu, J. M. (2001) Phylogenetic relationships of basal papilionoid legumes based upon sequences of the chloroplast trnL intron. Systematic Botany. 26(3). 537-556.

Radford, E. A., Watson, M. F., and Preston, J. (2001) Phylogenetic relationships of species of Aciphylla (Apiaceae, subfamily Apioideae) and related genera using molecular morphological, and combined data sets. New Zealand Journal of Botany. 39(2). 183-208.

Sinclair, W. T., Mill, R. R., Gardner, M. F., Woltz, P., Jaffre, T., Preston, J., Hollingsworth, M. L., Ponge, A. and Moller, M. (2002) Evolutionary relationships of the New Caledonian heterotrophic conifer, Parasitaxus usta (Podocarpaceae), inferred from chloroplast trnL-F intron/spacer and nuclear rRNA ITS2 sequences. Plant Systematics and Evolution. 233(1-2). 79-104.

Email: jcpxt8@studentmail.umsl.edu