Dr Danielle Roodt
Biochemistry, Genetics and Microbiology
My PhD research focused on the evolution and development of xylogenesis in land plant lineages. Since most research has focused on the angiosperms, I contributed to filling the gap in our knowledge of xylogenesis evolution by producing genomic resources for the three non-coniferous gymnosperms (Gnetales, cycads and ginkgo). Additionally, I am compared genomes of eudicots (such as Eucalyptus and Populus) and monocots (such as maize and rice) to better understand the evolution of secondary cell wall genes within the angiosperms, and published the manuscript "Loss of wood formation genes in monocot genomes" in Genome Biology and Evolution earlier this year. The angiosperms also show high prevalence for whole genome duplications (WGDs), which may have aided in their fast rise to ecological dominance, while these events are much rarer in the gymnosperms. I investigated whether evidence existed for remnants of ancient WGDs in the non-coniferous gymnosperms, and my manuscript entitled “Evidence for an ancient whole genome duplication in the cycad lineage” was published by the scientific journal PLoS ONE.
For my Postdoctoral research, I am investigating plant secondary metabolites. Plants produce a range of secondary metabolites which aid in defence against pests and pathogens, attracting pollinators, providing structural support and acting as signalling molecules between and within plants. Research into plant secondary metabolites has focused on the flowering plants, one of the seed plant lineages. The remaining lineages, belonging to the non-flowering gymnosperms, display unique and interesting secondary metabolism which has remained understudied. The discovery of novel genes involved in secondary metabolism from the gymnosperms can have industrial and economical importance, with application in wood processing, organic and renewable fuel sources and bio-based materials. An industrially important and well-studied metabolite is lignin, the presence of which is one of the main reasons for the difficulty in processing wood and producing wood-derived products. Lignin bound to cellulose is like cement encasing steel in hardened concrete. It is a variable and complex organic polymer responsible for the high energy and chemical costs of wood processing, but is important for waterproofing, structural strength and support in plants. Efforts are focusing on producing plants with altered lignin structures that process more readily, making it easier and cheaper to manufacture wood-derived products. The general steps in lignin biosynthesis are known, with most of the research to date focusing on agriculturally important species. However, important differences in lignin types exist between different plant lineages. In addition, cycad species contain many novel and unexplored secondary metabolites involved in unique nitrogen fixation and remarkable resistance to pests and disease. My postdoctoral work focuses on characterising candidate lignin biosynthesis genes in under-explored, “missing link” plant lineages and testing whether we could introduce unique structures into the stems of plants to make biomass breakdown more efficient, and constructing the first gene-metabolite atlas for a non-model plant of an indigenous cycad species for novel metabolite discovery.
FABIans reflected on the gains of the year and looked forward to 2019 and beyond at the annual year-end function and awards ceremony on 17 November.
The FABI flag flew high at this year’s SAWiSA gala event held at The Ranch Resort in Polokwane on Thursday 23 August, with two representatives attending as finalists: Dr Irene Barnes, a research leader in the DST-NRF Centre of Excellence in Tree Health Biotechnology (CTHB), and Danielle Roodt, a PhD candidate in the Forest Molecular Genetics (FMG) Programme.
Danielle Roodt, a PhD student in the FMG Research Programme and FABI, has been awarded an American Society of Plant Biologists (ASPB) Travel Award to attend and present her research at the upcoming Plant Biology Conference, a joint meeting of the ASPB, Canadian Society of Plant Biologists and the International Society of Photosynthesis Research.
My Journal Articles
|Roodt D, Li Z, Van de Peer Y, Mizrachi E. (2019) Loss of wood formation genes in monocot genomes. Genome Biology and Evolution 7(1):1986-1996.
|van der Nest MA, Wingfield MJ, McTaggart AR, Van Wyk S, De Vos L, Trollip C, Santana QC, Naidoo K, Dong TA, Wilken PM, Chan W-Y, Palmer M, Soal NA, Roodt D, Steenkamp ET, Wingfield BD. (2019) Genomic analysis of the aggressive tree pathogen Ceratocystis albifundus. Fungal Biology
|Roodt D, Lohaus R, Sterck L, Swanepoel RL, Van de Peer Y, Mizrachi E. (2017) Evidence for an ancient whole genome duplication in the cycad lineage. PLOS ONE 12(9):e0184454.
|van der Nest MA, Wingfield MJ, Wilken PM, Coetzee MPA, Naidoo K, Roodt D, Sauerman E, Godlonton T, Trollip C, McTaggart AR, Steenkamp ET, Wingfield BD. (2015) Saprophytic and pathogenic fungi in the Ceratocystidaceae differ in their ability to metabolize plant-derived sucrose. BMC Evolutionary Biology 15:273.
|Van der Nest MA, Beirn LA, Crouch JA, Demers JE, De Beer ZW, De Vos L, Gordon TR, Moncalvo JM, Naidoo K, Sanchez-Ramirez S, Roodt D, Santana QC, Slinksi SL, Stata M, Taerum SJ, Wilken PM, Wilson AM, Wingfield MJ, Wingfield BD. (2014) Draft genomes of Amanita jacksonii, Ceratocystis albifundus, Fusarium circinatum, Huntiella omanensis, Leptographium procerum, Rutstroemia sydowiana, and Sclerotinia echinophila. IMA Fungus 5(2):473-486.
|Van der Nest MA, Bihon W, De Vos L, Naidoo K, Roodt D, Rubagotti E, Slippers B, Steenkamp ET, Wilken PM, Wilson A, Wingfield MJ, Wingfield BD. (2014) Draft genome sequences of Diplodia sapinea, Ceratocystis manginecans, and Ceratocystis moniliformis. IMA Fungus 5(1):135-140.