title: Growth and development, and auxin polar transport of transgenic Arabidopsis under simulated microgravity conditions on a three-dimensional clinostat.
abstract: Growth and development, and auxin polar transport in Arabidopsis thaliana transformed with iaaH gene were studied under simulated microgravity conditions on a three-dimensional (3-D) clinostat. Simulated microgravity conditions on a 3-D clinostat did not affect the number of rosette leaves but promoted the growth and development (fresh weight of plant and the elongation of flower stalk) of transformants. Final growth of transformants under simulated microgravity conditions on a 3-D clinostat was almost equivalent to that grown on 1 g conditions in the presence of 1 micromoles IAM (indole-3-acetamide). The activities of auxin polar transport in the segments of flower stalk (inflorescence axis) of transformants grown on 1 g conditions were significantly promoted by the addition of IAM. Interestingly, simulated microgravity conditions on a 3-D clinostat also promoted the activities of auxin polar transport of transformants grown on the medium with or without IAM. Based on the results in this study, transgenic plants may not have an efficient homeostatic mechanism for the control of growth and development, and auxin polar transport activity in microgravity conditions in space.
authors.affiliation: College of Integrated Arts and Sciences, Osaka Prefecture University, 1-1 Gakuen-cho, Sakai, Osaka 599-8531, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Shimazu
authors.forename: Kensuke
authors.initials: K
authors.lastname: Miyamoto
authors.forename: Junichi
authors.initials: J
authors.lastname: Ueda
mesh_terms: D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D001692:Biological Transport; D018533:Biomass; D017343:Genes, Plant; D006112:Gravitation; D007210:Indoleacetic Acids / Q000378:metabolism / Q000493:pharmacokinetics* / Q000494:pharmacology; D010937:Plant Growth Regulators / Q000378:metabolism* / Q000494:pharmacology*; D018517:Plant Roots / Q000187:drug effects; D018547:Plant Stems / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D030821:Plants, Genetically Modified; D012399:Rotation; D018474:Weightlessness Simulation
chemical_list: D007210:Indoleacetic Acids; D010937:Plant Growth Regulators; C030737:indoleacetic acid; C015950:indoleacetamide