Renzaglia As one of the oldest living assemblages of terrestrial organisms, the hornworts are crucial to understanding the survival and diversification of early plants on land. With a worldwide distribution of approximately 150 species, the hornworts are tiny, inconspicuous plants that are poorly known, even by botanists. These plants exhibit unique and innovative means of coping with their existence on land, including positioning all vulnerable organs in mucilage-filled cavities that are nested within vegetative tissue. Intriguing features of the cell include a solitary chloroplast (photosynthetic organelle) that has an architecture reminiscent of algal cells. Detailed examination of such features will clarify more fully the changes that occurred when algae made the transition from water to land and ultimately gave rise to land plants. Despite their evolutionary importance and peculiar features, hornworts are among the few major groups of plants for which a comprehensive scientific study has yet to be conducted. This first examination of hornworts will provide a portrait of the phylogeny and biodiversity of the group from a global perspective. Information on genetic and structural diversity will be accumulated for hornworts collected from multiple geographic regions by an international assemblage of experts on these plants, headed by Dr. Robert Duff at University of Akron and Dr. Karen Renzaglia at Southern Illinois University. The goals are to: 1) establish a robust phylogeny of hornworts by generating and analyzing multiple data sets; 2) produce a revised classification based on the relationships established by the phylogenetic analyses; and 3) reconstruct global patterns of hornwort diversification and especially among the Australasian landmasses. The program will greatly expand knowledge of this widespread but relatively obscure group of evolutionarily significant plants, and will also explore more global issues relating to biological diversification and biocomplexity.
This project will have an impact on the infrastructure of education within the principal investigators' institutions, communities and beyond. Both PIs have demonstrated a strong commitment to providing enriching and supportive educational experiences for elementary, high school, undergraduate and graduate students. Students involved in the project will experience a wide range of professional activities and will be involved in all aspects of the research enterprise. Emphasis will be placed on attracting and mentoring students from underrepresented groups. The international component of this proposed program will provide the resources and opportunities for students to explore collaboration with students and scientists from a diversity of cultures and backgrounds. By the dissemination of data through presentations, publications and a Web site dedicated to the program, awareness of hornwort biology will be extended to the international scientific community as well as the general public. The results of this study will be valuable for informing decisions on conservation and environmental management as the habitats of these tiny ancient plants become increasingly threatened.
