Understanding nature's role in a biofuel future
A US-Dutch collaboration has advanced the science of turning crops into energy. The EU-funded research, published in Nature Cell Biology, has added to the field of knowledge on cellulose, the molecule that plant cell walls are made from and the key to producing the energy-rich crops of the future. The work, produced by scientists at the Wageningen University in the Netherlands and the Carnegie Institution for Science in the US, was funded in part by the 'New and Emerging Science and Technology' (NEST) activity of the European Union's Sixth Framework Programme (FP6). Science's understanding of cellulose, how it forms and its underlying processes, is rather limited. Nevertheless, its potential to help develop renewable, plant-based biofuels is enormous. It is for this reason that the US-Dutch team targeted the fibrous molecule in their research, to bring research one step closer to new sources of energy. 'Cellulose is the most abundant reservoir of renewable hydrocarbons in the world,' explained David Ehrhardt of Carnegie Institution's Department of Plant Biology and co-author of the paper. 'To understand how cellulose might be modified and how plant development might be manipulated to improve crop plants as efficient sources of energy, we need to first understand the cellular processes that create cellulose and build cell walls,' he added. As a starting point, the scientists used findings from a previous study (also undertaken by Professor Ehrhardt and the team), in which advanced imaging techniques were used to observe cellulose molecules within the Arabidopsis plant. In that study, the group created a fluorescent version of both the enzyme that makes cellulose fibres (cellulose synthase) and the protein behind microtubules (tubulin). The results proved that a connection exists between cell wall synthesis and microtubules (protein fibres), and it is this connection that determines the shape of the cell. For the current study, the team turned their attention to how the association between the cellulose synthase complexes and microtubules is triggered. They concluded that the protein network behind cellulose has a dual function; in addition to providing the framework for the structure of cell walls, it acts as a 'traffic cop', directing the important molecules that promote growth to the places they are needed. This means that we now know how the enzymes appear at the right position in the cell to create cellulose and ensure that the plant cells have the right shape. The findings also helped the scientists to add a new layer of information to the processes at work in the movement of plant microtubules, which they refer to as 'treadmilling'. They believe that the structures within the cell that contain cellulose synthase and that remain with the microtubules during longer, stressful periods are connected to this process, and it is only when the stress is lifted that the cellulose synthase is delivered by the organelles to the cell membrane.
Countries
Netherlands, United States