U-M scientist finds protein signal and receptor molecule plants use to control early cell development. Similar structures common in animal cells.
University of Michigan scientist Steven Clark has taken a major step toward understanding one of life's oldest mysteries--how genes work together in plants to turn generic cells into specialized cells destined to become leaves, stems or flowers.
The first identification of such a mechanism in plants is reported by Clark and his research associates in the July 28 issue of Science. It is a protein ligand-receptor pair--a common cell signaling technique used by animals from roundworms to humans to control transformations from unspecialized stem cells to specialized organ cells.
In addition to its significance for basic science, the discovery could have important applications in agriculture, according to Clark, an associate professor of biology at the U-M, who is affiliated with the U-M's Center for Organogenesis. Clark says researchers could use genetic engineering technology to increase flower and fruit production, or to control the timing of fruit development.
Clark works with Arabidopsis, a plant often used to study plant genetics and development. In the Science paper, he explains how an Arabidopsis gene called CLAVATA3 encodes a small protein signal called a ligand, which hangs out near patches of unspecialized plant cells called meristems. Another gene, CLAVATA1, encodes a receptor molecule, which penetrates meristem cell walls, with half the receptor on the outside and half inside the cell membrane.
When the ligand binds to the outer half of the receptor, it triggers chemical changes inside the meristem cell. A series of messenger molecules carry these chemical signals to genes in the cell nucleus telling them to turn off the locking signal that keeps meristem cells from developing. Once the locking signal stops, the meristem begins forming a tiny plant shoot, which will grow
Contact: Sally Pobojewski
University of Michigan