Effects of inhibitors of serine/threonine protein kinases on **Arabidopsis thaliana** root morphology and microtubule organization in its cells
Faculty of Sciences. Biology
Cell and Tissue Biology
, p. 399-409
University of Antwerp
The effect of different types of serine/threonine protein kinase inhibitors (cyclin-dependent, Ca2+-calmodulin dependent and protein kinase C) on the microtubule organization in cells of Arabidopsis thaliana main primary root zones were investigated in vivo. It was found that the microtubules in epidermal and cortex cells of transition and elongation zones, as well as microtubules in trichoblasts and atrichoblasts of the differentiation zone, were the most sensitive to the action of the investigated protein kinase inhibitors. It was established that, in these types of cells, microtubules change their initial orientation from transverse (oblique) to chaotic or longitudinal relative to the main primary root axis as a result of serine/threonine protein kinase inhibition. Microtubules in cells of root meristematic zone, as well as in root hairs, were less sensitive to the action of tested protein kinase inhibitors. Changes in the orientation of microtubules in cells of primary root zones under the effect of serine/threonine protein kinase inhibitors led to further disturbances in the growth and differentiation processes. It was assumed that the phosphorylation of microtubule proteins, primarily tubulin, could be involved in the regulation of these processes.