13 April: Nina Rønsted

Phylogeny predicts chemical diversity and potential medicinal activity of plants: evidence from Amaryllidaceae
 
Nina Rønsted, Associate Professor

Botanical Garden and Museum, Natural History Museum of Denmark

During evolution, plants and other organisms have developed a diversity of chemical defence lines, leading to the evolution of various groups of specialized metabolites selected for their endogenous biological function. A correlation between phylogeny and biosynthetic pathways could offer a predictive approach enabling more efficient selection of plants for traditional medicine and lead discovery. However, this relationship has rarely been rigorously tested and the potential predictive power is consequently unknown.

We produced the largest ever phylogenetic hypothesis for the medicinally important plant subfamily Amaryllidoideae (Amaryllidaceae) based on parsimony and bayesian analysis of nuclear, plastid and mitochondrial DNA sequences of over 100 species. We tested if alkaloid diversity and central nervous system related activities are significantly correlated with phylogeny.

  

Several genera are non-monophyletic emphasizing the importance of using phylogeny for interpretation of character distribution. Alkaloid diversity and in vitro central nervous system related activity are significantly correlated with phylogeny. This has implications for the use of phylogenies to interpret chemical evolution and biosynthetic pathways, to select candidate taxa for lead discovery, and to make recommendations for traditional use and conservation priorities.

23 March: Inger Kappel Schmidt

Plant responses to climate change in contrasting heathland ecosystems

Inger Kappel Schmidt

Dept. of Forest and Landscape Ecology, Forest and Landscape, Copenhagen University

Climate change affects the performance of species in different ways and potentially it changes community composition. In large scale climate manipulation experiments across Northern Europe, we studied the sensitivity of heathland species to climate during 12 years. A naturally occurring outbreak of heather beetles (Lochmaea suturalis Thompson) defoliated the heather at one site. This enabled studies of the climate sensitivity of adult plants as well as during the regenerative phase. We found the strongest effects of climatic change related to extreme events and biotic interactions resulting in a replacement of C. vulgaris with species connected to acid grassland. The transition was altered with extended drought periods and warming due to altered impact by the heather beetles and due to lower recruitment. The future climate with higher minimum temperatures and extended drought periods and with increased impact of herbivores and diminished window for regeneration may have major impact on the distribution of C. vulgaris heathlands and the area of heathlands in Europe may decrease further due to invasion by grasses and trees.