Time and cell cycle dependent formation of heterogeneous tubulin arrays induced by colchicine in Triticum aestivum root meristem

Abstract

We have investigated the appearance and reorganization of tubulin-containing arrays induced by colchicine in the root meristem of wheat Triticum aestivum, using immunostaining and electron microscopy. Colchicine caused depolymerization of microtubules and formation of tubulin cortical strands composed of filamentous material only in C-mitotic cells. After prolonged exposure to the drug, both interphase and C-mitotic cells acquired needle-type bundles, arranged as different crystalloids and/or macrotubules. The unmodified tyrosinated form of alpha-tubulin was detected within microtubules in control cells, but was not found within cortical strands. It was identified, however, within needle-type bundles. The modified acetylated form of alpha-tubulin, which was absent in control cells, was detected within needle-type bundles. Thus, cortical strands were transitory arrays, transformed into needle-type bundles during prolonged exposure to colchicine. Cortical strands appeared in a cell cycle-dependent manner, whereas needle-type bundles were cell cycle stable arrays. The diverse morphological organization, intracellular distribution and stability of tubulin-containing arrays may be associated with heterogeneity of alpha-tubulin isoforms. We assume that non-microtubular arrays substitute for microtubules in conditions where normal tubulin polymerization is inhibited.

Disturbance of reactive oxygen species homeostasis induces atypical tubulin polymer formation and affects mitosis in root‐tip cells of Triticum turgidum and Arabidopsis thaliana

“…They form and persist in cells experiencing: (a) hyperosmotic stress [Komis et al, 2001, 2002], (b) aluminum treatment [Frantzios et al, 2000] and (c) ROS homeostasis disturbance (present study). Macrotubule and tubulin paracrystal resistance might be due to the fact that they contain or consist of acetylated tubulin, at least in colchicine treated root‐tip cells of T. aestivum [Lazareva et al, 2003]. This hypothesis is supported by our data showing that the atypical tubulin polymers in MEN‐treated T. turgidum root‐tip cells contain acetylated tubulin (Figs.…”

“…Tubulin paracrystals form in cells experiencing hyperosmotic stress [Komis et al, 2001, 2002, 2006], colchicine treatment [Apostolakos et al, 1990; Karagiannidou et al, 1995; Lazareva et al, 2003; Caperta et al, 2006; Panteris et al, 2010] and treatment with Vinca alkaloids [for literature see Apostolakos et al, 1990; Lazareva et al, 2003]. In MEN‐treated cells, the strands of amorphous material observed (Figs.…”

“…In MEN‐treated cells, the strands of amorphous material observed (Figs. 11k and 11n) probably represent the tubulin matrix from which, the tubulin paracrystals arise [see also Apostolakos et al, 1990; Karagiannidou et al, 1995; Lazareva et al, 2003].…”

Genotoxic Effects of Raxil on Root Tips and Anthers of Allium cepa L.

“…Generally, cytotoxic substances inhibiting mitosis effect the microtubule configuration (Armbruster et al 1991). According to many investigators, abnormalities due to inhibition of spindle formation such as C-mitosis, multipolar anaphases, sticky and vagrant chromosomes, reflect high toxicity of pollutants (Amer and Alı 1974;Halıem 1990;Kovalchuk et al 1998;Lazareva et al 2003).…”

Crude extract of the cyanobacterium, Hapalosiphon sp., causes a cessation of root elongation and cell division in several plant species

“…Generally, the compounds inhibiting mitosis (M phase) affect microtubule configuration, which resulted in an increased proportion of cells arrested in the metaphase (Armbruster et al . 1991; Lazareva et al . 2003).…”