title: Quantitative Evaluation of Stomatal Cytoskeletal Patterns during the Activation of Immune Signaling in Arabidopsis thaliana.
abstract: Historically viewed as primarily functioning in the regulation of gas and water vapor exchange, it is now evident that stomata serve an important role in plant immunity. Indeed, in addition to classically defined functions related to cell architecture and movement, the actin cytoskeleton has emerged as a central component of the plant immune system, underpinning not only processes related to cell shape and movement, but also receptor activation and signaling. Using high resolution quantitative imaging techniques, the temporal and spatial changes in the actin microfilament array during diurnal cycling of stomatal guard cells has revealed a highly orchestrated transition from random arrays to ordered bundled filaments. While recent studies have demonstrated that plant stomata close in response to pathogen infection, an evaluation of stimulus-induced changes in actin cytoskeletal dynamics during immune activation in the guard cell, as well as the relationship of these changes to the function of the actin cytoskeleton and stomatal aperture, remains undefined. In the current study, we employed quantitative cell imaging and hierarchical clustering analyses to define the response of the guard cell actin cytoskeleton to pathogen infection and the elicitation of immune signaling. Using this approach, we demonstrate that stomatal-localized actin filaments respond rapidly, and specifically, to both bacterial phytopathogens and purified pathogen elicitors. Notably, we demonstrate that higher order temporal and spatial changes in the filament array show distinct patterns of organization during immune activation, and that changes in the naïve diurnal oscillations of guard cell actin filaments are perturbed by pathogens, and that these changes parallel pathogen-induced stomatal gating. The data presented herein demonstrate the application of a highly tractable and quantifiable method to assign transitions in actin filament organization to the activation of immune signaling in plants.
authors.affiliation: Department of Plant, Soil, and Microbial Sciences, 1066 Bogue Street A286, Michigan State University, East Lansing, Michigan, 48824, United States of America.
authors.forename: Masaki
authors.initials: M
authors.lastname: Shimono
authors.affiliation: Department of Integrated Biosciences, The University of Tokyo, Kashiwanoha 5-1-5, Kashiwa, Chiba, 277-8562, Japan.
authors.forename: Takumi
authors.initials: T
authors.lastname: Higaki
authors.affiliation: Department of Life Sciences, School of Agriculture, Meiji University, 1-1-1 Higashimita, Tama-Ku, Kawasaki, 214-8571, Japan.
authors.forename: Hanae
authors.initials: H
authors.lastname: Kaku
authors.affiliation: Department of Life Sciences, School of Agriculture, Meiji University, 1-1-1 Higashimita, Tama-Ku, Kawasaki, 214-8571, Japan.
authors.forename: Naoto
authors.initials: N
authors.lastname: Shibuya
authors.affiliation: Department of Integrated Biosciences, The University of Tokyo, Kashiwanoha 5-1-5, Kashiwa, Chiba, 277-8562, Japan.
authors.forename: Seiichiro
authors.initials: S
authors.lastname: Hasezawa
authors.affiliation: Department of Plant, Soil, and Microbial Sciences, 1066 Bogue Street A286, Michigan State University, East Lansing, Michigan, 48824, United States of America.|Graduate Program in Genetics, 2240E Biomedical Physical Sciences, Michigan State University, East Lansing, Michigan, 48824, United States of America.|Graduate Program in Cell and Molecular Biology, 2240A Biomedical Physical Sciences, Michigan State University, East Lansing, Michigan, 48824, United States of America.
authors.forename: Brad
authors.identifier: http://orcid.org/0000-0002-9880-4319
authors.initials: B
authors.lastname: Day
mesh_terms: D008841:Actin Cytoskeleton / Q000502:physiology; D017360:Arabidopsis / Q000276:immunology* / Q000502:physiology; D003599:Cytoskeleton / Q000502:physiology*; D010935:Plant Diseases / Q000276:immunology / Q000382:microbiology; D057865:Plant Immunity / Q000502:physiology*; D054046:Plant Stomata / Q000166:cytology / Q000502:physiology*