The Lewis B. and Dorothy Cullman Program for Molecular Systematics
The support of Lewis B. Cullman, with his wife of 46 years, the late Dorothy B. Cullman, has allowed The New York Botanical Garden to take advantage of new molecular and genomic techniques to analyze plants at their most essential levels. The preeminence of the Garden’s plant science research programs owes much to Lewis Cullman’s generosity and vision over more than two decades.
The Lewis B. and Dorothy Cullman Program for Molecular Systematics, founded in 1994, focuses the Garden’s plant molecular research on the global scientific effort to assemble the evolutionary Tree of Life for all plants and fungi. On the applied side, it focuses the Garden’s molecular research effort on DNA barcoding―a technique that uses small, standardized fragments of DNA as a species identity-tag. In partnership with the American Museum of Natural History, the Cullman Program focuses research efforts on plant-animal interactions at the level of the molecule.
The Evolutionary Tree of Life
In the global effort to assemble the Tree of Life for all species, the Cullman Program is a world leader in both the depth and breadth of research in plant evolution, or “phylogenetics.” The expertise of the Cullman Curators is spread across the plant kingdom, from the earliest branches of the green algae and land plants, through the gymnosperms, and to the major branches of the flowering plants. The evolutionary trees produced from these phylogenetic studies tell us how plants first arose, how they spread across the planet, and how they diversified into hundreds of thousands of different species, each with their own morphologies, anatomies, ecologies, and biochemical properties. As just several examples of current research, Dr. Kenneth Karol is using phylogenetic trees as a basic tool in the broad search for the origins of plants on land. Dr. Damon Little is using phylogenetic trees to identify genes and proteins that have transformed the morphologies of plants in their early evolution. Dr. Gregory Plunkett is using phylogenetic trees to detect patterns of plant origins and dispersal across the Pacific islands. Evolutionary trees produced from these individual studies, in turn, can be added to the total Tree of Life being assembled for all species on Earth. Dr. Dennis Stevenson is co-leading large, multi-institutional projects to elucidate all of the major groups of Earth’s gymnosperms (cycads, conifers, etc.) and monocots (lilies, orchids, cereals, etc.) for adding to the Tree of Life.
The DNA barcoding program within the Cullman Program provides world leadership for the multi-national and highly collaborative TreeBOL project to DNA barcode all 100,000 species of the trees of the world. Phase one will DNA barcode one representative tree species from each genus in which trees occur. The Garden regularly brings together scientists from around the world in a concerted effort to discuss two major foci of TreeBOL: the massive contributions made by participants to the growing DNA barcoding database; and the development of practical, real-world applications of DNA barcoding data.
In addition, the Cullman Program is defining “mini-barcodes” that can be used to identify species using highly degraded residual DNA in dietary supplements such as black cohosh (used in treating the symptoms of menopause). The Program is also initiating studies that will make it possible to use DNA barcodes to identify rare and endangered plants species such as orchids, cycads, and certain timber trees to prevent illegal trade across international borders. Dr. Damon Little is designing computer programs that more efficiently and accurately identify species using their DNA barcodes.
Plant-Animal Interactions at the Level of the Molecule
Cullman Program scientists work with counterparts at the American Museum of Natural History (AMNH) to study the co-evolution of plants and animals. One focus is insect-plant interactions and pollination biology. Using molecular approaches, the evolutionary history of particular plants and the evolutionary history of the particular insects that pollinate them are separately ascertained. Comparisons of the complementary changes that have occurred in the flowers and the pollinating insects through time reveal the degree to which co-evolution has occurred. A second focus of mutual interest is looking at the horizontal gene transfer of biosynthetic pathways from microorganisms (mainly bacteria) inhabiting plants, to the host plants themselves. Botanical Garden and AMNH scientists are trying to understand how common such transfer events are and in what respect they have influenced plant evolution.
Cullman Program scientists at the Garden and the AMNH co-lead a training program for an international community of scientists in the techniques of DNA barcoding. Cullman Program scientists are also developing a shared database of DNA barcodes that can assist in enforcement of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES).
See also: Genomics Program
The Lewis B. and Dorothy Cullman Program for Molecular Systematics occupies the Lewis B. and Dorothy Cullman Laboratory and other laboratory and programmatic space in the Botanical Garden’s Pfizer Plant Research Laboratory. The Cullman Program is fully equipped for all standard forms of molecular analysis, including DNA and RNA extraction, high throughput polymerase chain reaction (PCR), quantitative PCR, high throughput DNA extraction, molecular cloning, agarose gel image analysis, and computer-assisted DNA sequencing. Gene sequencing and DNA fingerprinting are performed on automated sequencers located both at the Garden and in our shared laboratory at the American Museum of Natural History in Manhattan.
The DNA Bank of The New York Botanical Garden serves as the repository of frozen tissue and genomic DNA samples that are the foundation for research conducted in the Lewis B. and Dorothy Cullman Program for Molecular Systematics and the Genomics Program. The DNA Bank also provides long-term storage of readily available plant and fungal samples for research by the broader scientific community. Online documentation of the DNA Bank includes links to high resolution images of associated voucher specimens via the C.V. Starr Virtual Herbarium.