Jeffrey P. Hill, Ph.D.
Associate Professor of Botany
Plant Development and Evolution
hilljeff@isu.edu
208-282-2650
Rm 440 Gale Life Sciences Bldg.
Education
B.S. Biology, 1982, State University of New York, Binghamton
M.S. Botany, 1984, University of California, Davis
Ph.D. Botany, 1989, University of California, Riverside
USDA Postdoctoral Fellow, 1990-91, University of Georgia, Athens
Teaching
BIOL 405 Plant Form & Function
BIOL 406 Plant Diversity & Evolution
BIOL 417 Organic Evolution
BIOL 491/492 Senior Seminar
Biographical Sketch
I have always been interested in the biology of organisms and their functional relationships to nature. I spent much of my time as an undergraduate radio-tracking small mammal in the meadows and woodlands of upstate New York to understand animal behavior in relation to their social structure and seasonal change. Since that time, I have been studying plant development and evolution, especially at the anatomical and morphological levels. This work has ranged from investigations of plants carrying a single gene mutation that alters flower development in Arabidopsis thaliana to studies of the evolution of self-pollinating flower morphology in Arenaria uniflora. These efforts were intended to discover how variation in the genes that regulate reproductive development in flowering plants gets translated into phenotypic differences via development.
More recently, I have turned my attention to the biology of Ceratopteris richardii, a fern with a fast life cycle that makes it an excellent model for both teaching and research (http://cfern.bio.utk.edu/). Like other non-seed plants, ferns have a life cycle that includes a free-living haploid stage along with the larger diploid stage that the lay person normally recognizes as “the fern”. For many years, it has been known that simple sugars may constitute an important signaling molecule that allows the cells in many different fern species to switch from one stage of the life cycle to the other in the absence of fertilization or meiosis. One project that my lab has helped to co-sponsor (with Dr. Mike Thomas and Ph.D. student Deborah Johnson) is a characterization of the sugar transporter gene family in land plants. This is an ancient gene family with an interesting pattern of evolution in its own right, and these genes may be very important in regulating basic aspects of fern life cycle biology as well. One of the first steps necessary to understand the role that sugar transporters play in the life cycle to is to discover the number and nature of the genes present in the genome. The gene family has turned out to be large and complex, with many specialized intra- and intercellular transport functions implicated.
Another aspect of fern biology that has held my interest concerns the evolution of gender expression in plants. In ferns like Ceratopteris, sex expression is limited to the haploid phase. In more advanced flowering plants, the production of gametes is still restricted to the haploid stage (e.g., pollen makes sperm), but there has been a significant shift towards gender expression in the diploid plant (the one that makes flowers with male and/or female sex organs). The shift in sex expression from purely haploid (as seen in Ceratopteris) to a haploid plus diploid condition (as seen in flowering plants) poses some interesting problems for the evolution of gender in land plants that I hope to investigate further.
Selected Publications
2006 Johnson, D.A., J.P. Hill and MA Thomas The monosaccharide transporter gene family in land plants is ancient and shows differential expression and expansion across lineages. BMC Evolutionary Biology 6:64-100.
2004 Hou G.C. and J.P. Hill Developmental anatomy of the fifth shoot-borne root in young sporophytes of Ceratopteris richardii Planta 219:212-220.
2004 Hou, G.C., J.P. Hill and E Blancaflor. Developmental anatomy and auxin response of lateral root formation in Ceratopteris richardii. Journal of Experimental Botany 55:685-693.
2002 Hou, G.C. and J.P. Hill. Heteroblastic root development in Ceratopteris richardii (Parkeriaceae). International Journal of Plant Sciences. 163:341-351.
2001 Hill, J.P. Meristem development at the sporophyll pinna apex in Ceratopteris richardii. International Journal of Plant Sciences. 162:235-247.