FORMATION OF ATYPICAL TUBULIN STRUCTURES IN PLANT CELLS AS A NONSPECIFIC RESPONSE TO ABIOTIC STRESS
Е. А. Smirnova, M. R. Khaliluev, N. K. Christov, E. N. Baranova, E. G. Todorovska, L. V. Kurenina
Abstract: In response to abiotic and biotic stress factors the production of reactive oxygen species (ROS) in plant cells is increased and series of cascade reactions for their neutralization are being triggered. Targets of ROS in cells can be various biochemical and physiological processes, as well as cellular organelles including the cytoskeleton. Many abiotic stress factors, by provoking increase of the level of ROS in plant cells, elicit reorganization of the microtubules leading to disruption of mitosis. The reorganization of interphase and mitotic microtubule system was proposed to be an integral part of the response of cells to external stimuli. The state of microtubule system (tubulin cytoskeleton) under various abiotic stresses, including salinity, low temperatures, Al toxicity and flooding, was analysed in cells of representatives of family Solanaceae (S. lycopersicum L., S. tuberosum L. and N. tabacum L.) and cereals (T. aestivum L. and H. vulgare L.) by using transmission electron microscopy.
Various tubular structures that were structurally different from microtubules were observed in plant cells subjected to abiotic stress. Fibrillar bundles with different densities of their constituent components, macrotubules, orderly packed paracrystalline aggregates and strands having hexagonal packing in cross sections, were observed in potato leaf mesophyll cells under low positive temperature stress, wheat root cells subjected to flooding stress, barley root cells under Al toxicity stress, as well as in
root cells of tomato and tobacco under salinity stress imposed by NaCl or Na2SO4. The structure of these cytoskeletal elements is identical to stable atypical tubulin polymers induced by different chemical treatments. The presented data suggests that the formation of abnormal tubulin structures in plant cells is a common and non-specific response to various abiotic stress factors.
Various tubular structures that were structurally different from microtubules were observed in plant cells subjected to abiotic stress. Fibrillar bundles with different densities of their constituent components, macrotubules, orderly packed paracrystalline aggregates and strands having hexagonal packing in cross sections, were observed in potato leaf mesophyll cells under low positive temperature stress, wheat root cells subjected to flooding stress, barley root cells under Al toxicity stress, as well as in
root cells of tomato and tobacco under salinity stress imposed by NaCl or Na2SO4. The structure of these cytoskeletal elements is identical to stable atypical tubulin polymers induced by different chemical treatments. The presented data suggests that the formation of abnormal tubulin structures in plant cells is a common and non-specific response to various abiotic stress factors.
Keywords: cytoskeleton; microtubule; stress condition; tubulin; ultrastructure
Date published: 2017-08-31
Download full text