FMG Research Interests
Background
Forest trees are large, long-lived perennials with genetic characteristics that are very similar to that of humans. They play extremely important roles in global carbon sequestration, and constitute excellent renewable resources for a diversity of fibre and lignocellulose-based raw materials. In addition to their use for pulp and paper production and for solid wood products, they are increasingly viewed as potential biorefineries for the production of novel biopolymers and biofuels. With the depletion of fossil fuel reserves and the reality of accelerated global warming, large international research efforts are currently under way to modify the growth and wood properties of trees to make them more amenable to bioenergy production. Excellent progress has been made in the analysis of forest tree genomes and the development of biotechnology tools to modify growth and wood properties in trees. The poplar tree genome recently became the first woody plant genome to be sequenced, and the Eucalyptus genome is currently being sequenced. Global gene expression studies (e.g. microarray analyses) are being used in several tree species to characterize patterns of gene expression during wood formation and responses to different biological and environmental stresses. Forest genomics is an exciting new area of research that is allowing researchers to answer questions that were until recently intractable to scientific investigation. Furthermore, financial support from large industrial partners is creating tremendous opportunities for biotechnology innovation and future careers in plant biotechnology.
Research Focus
Research in the Forest Molecular Genetics (FMG) Programme focuses on the molecular genetics and genomics of xylogenesis, the developmentally regulated process through which wood fibre is formed and which is fundamental to carbon fixation in plants. We are addressing important scientific questions such as the genetic control of carbon partitioning into cellulose, hemi-cellulose and lignin, the major biochemical constituents of wood fibre. An early achievement of the programme was the isolation of the cellulose synthase (CesA) genes of Eucalyptus trees, the most widely grown plantation tree species in the world. CesA genes encode a multimeric enzyme complex that polymerizes activated glucose molecules into very long cellulose chains and deposits these cellulose chains into plant cell walls. Cellulose is the most abundant biopolymer on earth and yet very little is known about the genetic regulation of its biosynthesis. Several FMG student projects are therefore focused on the transcriptional regulation of CesA genes and the involvement of a novel class of small RNAs, called MicroRNAs, in the genetic regulation of cell wall formation in trees. This line of investigation also allows us to study other aspects of xylogenesis such as the control of cell division from stem cells in the vascular cambium; cell fate determination; pattern formation and cell differentiation. Xylogenesis is certainly an excellent model to study basic plant developmental genetics.
Current Activities, Collaborations and Funding
As part of our focus on the molecular genetics of xylem development in fast-growing Eucalyptus and tropical pine tree species, we are using high-throughput molecular technologies for gene discovery and functional genetics research; allele discovery research, and the development of molecular breeding tools for the genetic improvement of targeted forest tree species. We are using the herbaceous model plant, Arabidopsis thaliana, to perform functional genetic analysis of candidate wood formation genes discovered in trees, and will soon extend this to direct transformation into Eucalyptus.
Most of the research activities in the FMG programme are funded as part of the Wood and Fibre Molecular Genetics (WFMG) sub-programme, which is a joint research venture of the University of Pretoria, Sappi Forests and Mondi Business Paper South Africa. Additional financial and student support is provided by the Technology and Human Resources for Industry Programme (THRIP) and the National Research Foundation of South Africa (NRF), with an international collaborator in Australia. Recent developments in our research programme include a collaborative project with North Carolina State University and Kazusa DNA Research Institute in Japan to clone and identify microRNAs putatively involved in xylem development. The FMG programme has collaborative links with tree biotechnology research groups at North Carolina State University, the University of British Columbia, the University of Melbourne and the University of Tasmania. This allows us to send M.Sc. and Ph.D. students overseas for periods of three to six months to work on collaborative projects. We also currently host the International Eucalyptus Genome Network (EUCAGEN).