Scientists at the University of Manchester (UK) have identified the genes that make plants grow outwards, and plan to use their research to increase plant biomass in trees and other species, thus helping meet the need for renewable resources. A paper on their work was published 10 February in the journal Development.
Professor Simon Turner and Dr Peter Etchells, at the Faculty of Life Sciences, studied the plant Arabidopsis which has vascular system similar to that of trees. They investigated growth in the vascular bundles and found that the genes PXY and CLE41 directed the amount and direction of cell division. Furthermore, they found over-expression of CLE41 caused a greater amount of growth in a well-ordered fashion, thus increasing wood production.
Our work has identified the two genes that make plants grow outwards. The long, thin cells growing down the length of a plant divide outwards, giving that nice radial pattern of characteristic growth rings in trees. So you get a solid ring of wood in the centre surrounded by growing cells. Now we have identified the process by which the cells know how to grow outwards, we hope to find a way of making that plants grow thicker quicker, giving us the increased wood production that could be used for biofuels or other uses. And there is an added benefit. There are concerns that the growing of biofuel products competes with essential food production. However, the part of the plant we have studied is the stalk—not the grain—so there will be no competition with food production—Simon Turner
The team are now growing poplar trees in the lab to see if they fit the Arabidopsis model. They will use these results to develop a system of increasing wood production.
J. Peter Etchells and Simon R. Turner (2010) The PXY-CLE41 receptor ligand pair defines a multifunctional pathway that controls the rate and orientation of vascular cell division. Development 137:767-774; doi: 10.1242/dev.044941