Plant Biology, Ohio State University Microtubules appear to play various roles in stomatal development.
Stomata originate from highly regulated asymmetric and symmetric cell divisions.
In Arabidopsis, the first asymmetric division yields two unequal cells, the smaller of which is the meristemoid. An equal division of the GMC produces the two guard cells. The location of both types of divisions is predicted by a preprophase band of cortical microtubules. In addition, the GMC is unique in having wall thickenings that mark the division site. Guard cell morphogenesis also involves characteristic microtubular arrays such as anticlinally arranged microtubules along the developing pore wall, and radial arrays that parallel the distinct arrangement of cellulose in the kidney-shaped guard cell.