title: Experimental virus evolution reveals a role of plant microtubule dynamics and TORTIFOLIA1/SPIRAL2 in RNA trafficking.
abstract: The cytoskeleton is a dynamic network composed of filamentous polymers and regulatory proteins that provide a flexible structural scaffold to the cell and plays a fundamental role in developmental processes. Mutations that alter the spatial orientation of the cortical microtubule (MT) array of plants are known to cause important changes in the pattern of cell wall synthesis and developmental phenotypes; however, the consequences of such alterations on other MT-network-associated functions in the cytoplasm are not known. In vivo observations suggested a role of cortical MTs in the formation and movement of Tobacco mosaic virus (TMV) RNA complexes along the endoplasmic reticulum (ER). Thus, to probe the significance of dynamic MT behavior in the coordination of MT-network-associated functions related to TMV infection and, thus, in the formation and transport of RNA complexes in the cytoplasm, we performed an evolution experiment with TMV in Arabidopsis thaliana tor1/spr2 and tor2 mutants with specific defects in MT dynamics and asked whether TMV is sensitive to these changes. We show that the altered cytoskeleton induced genetic changes in TMV that were correlated with efficient spread of infection in the mutant hosts. These observations demonstrate a role of dynamic MT rearrangements and of the MT-associated protein TORTIFOLIA1/SPIRAL2 in cellular functions related to virus spread and indicate that MT dynamics and MT-associated proteins represent constraints for virus evolution and adaptation. The results highlight the importance of the dynamic plasticity of the MT network in directing cytoplasmic functions in macromolecular assembly and trafficking and illustrate the value of experimental virus evolution for addressing the cellular functions of dynamic, long-range order systems in multicellular organisms.
authors.affiliation: Institut de Biologie Moléculaire des Plantes, UPR2357 CNRS, Strasbourg, France.
authors.forename: Eduardo José
authors.initials: EJ
authors.lastname: Peña
authors.affiliation: Instituto Valenciano de Investigaciones Agrarias, Moncada, Valencia, Spain.
authors.forename: Inmaculada
authors.initials: I
authors.lastname: Ferriol
authors.affiliation: Department of Comparative Neurobiology, Institut Cavanilles de Biodiversitat i Biologia Evolutiva CIBERNED, Universidad de Valencia, Valencia, Spain.
authors.forename: Adrián
authors.initials: A
authors.lastname: Sambade
authors.affiliation: Institute for Botany, University of Osnabrück, Osnabrück, Germany.
authors.forename: Henrik
authors.initials: H
authors.lastname: Buschmann
authors.affiliation: Department of Environmental Sciences, Plant Physiology, University of Basel, Basel, Switzerland.
authors.forename: Annette
authors.initials: A
authors.lastname: Niehl
authors.affiliation: Instituto de Biología Molecular y Celular de Plantas, CSIC-UPV, Valencia, Spain; The Santa Fe Institute, Santa Fe, New Mexico, United States of America.
authors.forename: Santiago F
authors.initials: SF
authors.lastname: Elena
authors.affiliation: Instituto Valenciano de Investigaciones Agrarias, Moncada, Valencia, Spain.
authors.forename: Luis
authors.initials: L
authors.lastname: Rubio
authors.affiliation: Institut de Biologie Moléculaire des Plantes, UPR2357 CNRS, Strasbourg, France; Department of Environmental Sciences, Plant Physiology, University of Basel, Basel, Switzerland.
authors.forename: Manfred
authors.initials: M
authors.lastname: Heinlein
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism / Q000821:virology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D005075:Biological Evolution; D054884:Host-Pathogen Interactions; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism*; D008870:Microtubules / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D010935:Plant Diseases / Q000235:genetics / Q000821:virology*; D012313:RNA / Q000235:genetics / Q000378:metabolism; D034443:RNA Transport; D014027:Tobacco Mosaic Virus / Q000235:genetics / Q000502:physiology*
chemical_list: D029681:Arabidopsis Proteins; D008869:Microtubule-Associated Proteins; C496076:SPIRAL2 protein, Arabidopsis; D012313:RNA