title: Progressive transverse microtubule array organization in hormone-induced Arabidopsis hypocotyl cells.
abstract: The acentriolar cortical microtubule arrays in dark-grown hypocotyl cells organize into a transverse coaligned pattern that is critical for axial plant growth. In light-grown Arabidopsis thaliana seedlings, the cortical array on the outer (periclinal) cell face creates a variety of array patterns with a significant bias (>3:1) for microtubules polymerizing edge-ward and into the side (anticlinal) faces of the cell. To study the mechanisms required for creating the transverse coalignment, we developed a dual-hormone protocol that synchronously induces ∼80% of the light-grown hypocotyl cells to form transverse arrays over a 2-h period. Repatterning occurred in two phases, beginning with an initial 30 to 40% decrease in polymerizing plus ends prior to visible changes in the array pattern. Transverse organization initiated at the cell's midzone by 45 min after induction and progressed bidirectionally toward the apical and basal ends of the cell. Reorganization corrected the edge-ward bias in polymerization and proceeded without transiting through an obligate intermediate pattern. Quantitative comparisons of uninduced and induced microtubule arrays showed a limited deconstruction of the initial periclinal array followed by a progressive array reorganization to transverse coordinated between the anticlinal and periclinal cell faces.
authors: Department of Biology, Indiana University, Bloomington, Indiana 47405, USA.
authors: Laura
authors: L
authors: Vineyard
authors: Andrew
authors: A
authors: Elliott
authors: Sonia
authors: S
authors: Dhingra
authors: Jessica R
authors: JR
authors: Lucas
authors: Sidney L
authors: SL
authors: Shaw
mesh_terms: D017360:Arabidopsis / Q000166:cytology* / Q000187:drug effects / Q000235:genetics; D005875:Gibberellins / Q000494:pharmacology*; D018546:Hypocotyl / Q000166:cytology* / Q000254:growth & development; D007210:Indoleacetic Acids / Q000494:pharmacology*; D008027:Light; D008870:Microtubules / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure*; D030821:Plants, Genetically Modified; D013997:Time Factors
chemical_list: D005875:Gibberellins; D007210:Indoleacetic Acids; C030737:indoleacetic acid; C007842:gibberellic acid