Protein that triggers plant cell division revealed by r...( From the valves in a human heart to ...)

From the valves in a human heart to the quills on a porcupine to the petals on a summer lily, the living world is as varied as it is vast. For this to be possible, the cells that make up these living things must be just as varied. Parent cells must be able to divide in ways that create daughter cells that are different from each other, a process called asymmetric division. Scientists know how this happens in animals, but the process in plants has been a mystery.

Now Stanford biologists have found a plant protein that appears to play a key role in this type of cell division. The presence of the protein, called BASL, is vital to asymmetric cell division. In plant cells where it was absent, the cells did not divide.

"This is crucial information if we really want to understand plants' unique ways of making the different types of cells in their bodies," said Dominique Bergmann, an assistant professor of biology.

Bergmann, along with Juan Dong, a postdoctoral researcher, and Cora MacAlister, a doctoral candidate, both in the Biology Department, tracked BASL in epidermal cells of Arabidopsis, a small plant used for genetic studies. The epidermis of Arabidopsis contains small pores called stomata that allow the plant to breathe and these stomata are generated by asymmetric cell divisions. The three researchers have written a paper describing their work that will be published online June 11th in the journal Cell.

"For asymmetric cell division in animals, we know many of the proteins that control the process, but plants just don't make any of those proteins," Bergmann said.

By following where in the cell BASL resides during successful asymmetric cell divisions, they have discovered that BASL behaves like many of the proteins vital for animal asymmetric cell divisions, even though BASL's structure doesn't look like any of them.

Bergmann, Dong, and MacAlister tracked BASL by adding
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