A fertilised plant cell divides into two, four, eight, sixteen and more identical cells. Biochemists from Wageningen have now discovered that there are differences in this young, uniform lump of cells that eventually develops into roots, leaves or flowers. “This is the first fundamental step towards the possible steering of the development of plants,” says Dolf Weijers, Professor of Biochemistry of Plant Development at Wageningen University.
“Normally, a cell divides into two identical daughter cells by developing a new cell wall via the shortest path through the cell,” Weijers explains. “This principle was described as early as the late nineteenth century. However, if this principle would continue infinitely, a dividing plant cell would eventually become like a ballo f soap bubbles. We have now discovered that the plant hormone auxin is responsible for the fact that cells duck out of this basic rule, and are able to develop two different daughter cells from a single cell.”
Measuring and describing dividing cells
Weijers and his colleagues were able to make their discovery due to enhanced microscopic techniques. “It allowed us to study dividing cells in 3D. We also used calculation models that enabled us to measure and describe dividing cells and see whether the cells divided via the shortest path or not.”
From two to three-dimensional research
The work of Weijers and his colleagues was in fact a continuation of earlier two-dimensional research, in which Wageningen development biologist Professor Ben Scheres was involved. “In the early 1990s we, and several other groups, performed two-dimensional research into how plant embryos divide,” Scheres says. “It is a great step forward that Professor Weijers has now managed to show this in three dimensional form in a very aesthetically pleasing way.”
More or less wood
Both scientists point out that the work is an important element within the framework of fundamental science. Scheres: “It is a crucial step into understanding the differentiation of plant cells. Now we know that auxin plays a leading role in regulating asymmetric cell division we will have to start looking for the next steps. We already knew in an empirical sense that it was possible to produce rooting powder based on synthetic auxin, which could be used to stimulate the root growth of plant shoots. This publication represents a much more fundamental step towards an actual scientific understanding of the division and differentiation of cells.”
“Eventually, the results may lead to applied research,” Weijers adds. “If anyone wished to steer, say, the number of transport vessels in plants, they could also steer the woodiness of plants. Depending on your interests, whether you are a furniture maker or a producer of biodiesel, you could stimulate the development of a plant that produces either more or less wood.”
At this time, the breakthrough is mainly a step forward in fundamental science. Breeders and other application colleagues will have to be patient a little while longer. Scientists, including those at Wageningen UR, will use the new knowledge for fundamental research and research that is slightly more geared towards innovation.