Evolution and Diversity
Our research
Led by Professor Sam Brockington, the Evolution and Diversity Research Group is investigating the the origin, evolution and diversification of the plant kingdom. Plants are an exceptionally diverse and successful group of organisms comprising more than 400,000 species. Over the past 470 million years they have colonised almost every conceivable environment from harsh deserts to arctic tundra, and have profoundly altered Earth's atmosphere, climate and geochemistry. The Group's research focuses on fundamental questions surrounding the origin, evolution and diversification of the plant kingdom.
The Group's research is both comparative and integrative, combining systematics, morphology, development, molecular genetics and physiology. The major theme that unites these different approaches is phylogeny, which we use to reconstruct the evolutionary history of organismal and gene diversity to provide a comparative framework for our work. Major areas of interest currently include the phylogenetic relationships within flowering plants especially the order Caryophyllales, evolutionary biosynthesis of metabolic pathways focusing on betalain biosynthesis in Caryophyllales, the evolution and conservation of Tulips and the evolution of fog-harvesting geophytes in Namaqualand.
Caryophyalles systematics and evolution
Angiosperms, or flowering plants, are the most diverse and dominant of the land plant lineages comprising some 350,000 species, including all major crop plants. Supervised by Douglas and Pamela Soltis, Professor Brockington aquired an interest in the broader brush strokes of angiosperm systematics. He did his PhD on the Evolution and Development of Petals in Aizoaceae (Caryophylalles) and participated in several international collaborations to reconstruct the angiosperm phylogeny, such as the Angiosperm Tree of Life Project. His involvement has focused in particular on the the Caryophyllales. Currently Professor Brockington and his group are collaborating with Michael Moore and Stephen Smith to apply transcriptomic approaches to understand phylogeny, molecular rate and trait evolution within Caryophyllales. The Caryophyllales is a general source of inspiration for Dr Brockington's research into trait evolution, including the evolution of betalain biosynthesis discussed below.Publications:
- '‘Living stones’ reveal alternative petal identity programs within the core eudicots', (2011), The Plant Journal
- 'Phylogeny of the Caryophyllales sensu lato: Revisiting hypotheses on pollination biology and perianth differentiation in the core Caryophyllales', (2009), International Journal of Plant Science
- 'Dissecting molecular evolution in the highly diverse plant clade Caryophyllales using transcriptome sequencing', (2015), Molecular Biology and Evolution
Betalains and Tyrosine metabolism in Caryophyllales
A major focus of the Group is understanding the evolutionary biosynthesis of the unique betalain pigments in Caryophyllales. All land plants are coloured with flavonoids such as anthocyanins. Caryophyllales are the exception as many lineages have lost anthocyanin pigmentation, which has been replaced by tyrosine-derived betalain pigments. The Group has developed tools to detect specialised metabolic gene radiations, described the role of gene duplication and neofunctionalisation in the evolution of the betalain pathway, identified a betalain-related gene cluster, and supported the characterisation of novel genes in betalain biosynthesis. They recently identified the convergent evolution of betalain biosynthesis and have genetically manipulated primary metabolism to engineer an eight-fold increase in betalain production in heterologous host systems.Publications:
- 'Redirecting primary metabolism to boost production of tyrosine-derived specialised metabolites in Planta', (2018), Scientific Reports
- 'Lineage-specific gene radiations underly the evolution of novel betalain pigmentation in Caryophyllales', (2015), New Phytologist
- 'Complex evolution of pigmentation in the Caryophyllales', (2011), New Phytologist
- 'Relaxation of tyrosine pathway regulation underlies the evolution of betalain pigmentation in Caryophyllales', (2017), New Phytologist
- 'The evolution of betalain biosynthesis in Caryophyllales', (2019), New Phytologist
Ex-situ and In-situ plant conservation
As Curator of a major ex-situ living collection of plants at the Cambridge University Botanic Garden, Professor Brockington has become interested in the field of plant conservation, and the integration of ex-situ collections and in-situ conservation through science-informed best practice. The Group's primary contribution here has been an analysis of the world-wide ex-situ collection of plants held in the global botanic garden network, examining the potential of living collections for plant conservation. They have also examined the relative contribution and significance of global and sub-global datasets of plant threat assesments. As the National Collection Holders for Tulips in the UK, they are currently involved in understanding the evolution of tulips and their conservation in Central Asia, in collaboration with Flora and Fauna International, and collaborators in Kyrgyzstan, funded by the Darwin Initiative.Publications:
- 'Ex-situ conservation of plant diversity in the world’s botanic gardens', (2017), Nature Plants
- 'Comparing and contrasting evidence-based threat assessments of plant species at the global and sub-global level', (2018), Biodiversity and Conservation
- 'Botanic Gardens and Solutions to Global Challenges Chapter in Plant Conservation Science and Practice: The Role of Botanic Gardens', (2017), Cambridge University Press
Fog-harvesting plants of Namaqualand
Professor Brockington loves doing field work in South Africa and has a growing interest in the remarkable geophytes of South Africa, especially in the Northern and Western Capes. The Group are currently studying the phenomenon of fog-harvesting plants, which have been suggested to harvest non-precpitating moisture from the air. Their focal groups are Gethyllis and Eriospermum, which have both been suggested to be fog harvesting. They are reconstructing the phylogenetic history of Eriospermum in order to understand the evolution of their remarkable leaf structures, and conducting physiology experiments to explore to what extent they harvest moisture from the air.More information
To find out more about the research carried out by the Evolution and Diversity Research Group visit the Brockington Lab website.