title: 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.
authors.affiliation: Department of Cell Biology and Histology, Biology Faculty, Moscow State University, 119992, Moscow, Russia.
authors.forename: Elena M
authors.initials: EM
authors.lastname: Lazareva
authors.forename: Vladimir Y
authors.initials: VY
authors.lastname: Polyakov
authors.forename: Yuri S
authors.initials: YS
authors.lastname: Chentsov
authors.forename: Elena A
authors.initials: EA
authors.lastname: Smirnova
mesh_terms: D002453:Cell Cycle / Q000502:physiology; D002455:Cell Division / Q000187:drug effects / Q000502:physiology; D003078:Colchicine / Q000494:pharmacology*; D007150:Immunohistochemistry; D018519:Meristem / Q000187:drug effects / Q000378:metabolism*; D008854:Microscopy, Electron; D008870:Microtubules / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D013997:Time Factors; D014908:Triticum / Q000187:drug effects / Q000378:metabolism*; D014404:Tubulin / Q000096:biosynthesis* / Q000378:metabolism
chemical_list: D014404:Tubulin; D003078:Colchicine