A study from Purdue University led by Daniel Szymanski has mapped a complex
series of pathways that control the shape of plant cells. The research team
used the model plant Arabidopsis to map the complex pathways that control
plant cell shape. The findings may be key to improving the quality of cotton
grown in the United States.
Szymanski, professor in the Department of Botany and Plant Pathology,
analyzed how intracellular signaling networks pattern cell walls to generate
particular cell shapes and sizes. In a paper published in Current Biology,
Szymanski described how microtubules and actin, protein polymers that form
the cytoskeletons of plant cells, are organized to specify the mechanical
properties of cell walls that define cell shape.
The research group found that microtubules entrap a protein called SPIKE 1
within the apex of another cell where SPIKE 1 recruits additional protein
machineries that cause actin filaments to form. Actin filament networks are
then organized as roadways for long-distance intracellular transport and the
regulated delivery of cell wall materials that are necessary for cell
According to Szymanski, SPIKE 1 is a master regulator in cells, a switch
that when activated determines the time and location where actin networks
are polymerized. He added that the location and activity of SPIKE1 is
important. Without it, growth is misregulated, leading to distorted cell
shapes that do not taper properly.