title: TaADF4, an actin-depolymerizing factor from wheat, is required for resistance to the stripe rust pathogen Puccinia striiformis f. sp. tritici.
abstract: Actin filament assembly in plants is a dynamic process, requiring the activity of more than 75 actin-binding proteins. Central to the regulation of filament assembly and stability is the activity of a conserved family of actin-depolymerizing factors (ADFs), whose primarily function is to regulate the severing and depolymerization of actin filaments. In recent years, the activity of ADF proteins has been linked to a variety of cellular processes, including those associated with response to stress. Herein, a wheat ADF gene, TaADF4, was identified and characterized. TaADF4 encodes a 139-amino-acid protein containing five F-actin-binding sites and two G-actin-binding sites, and interacts with wheat (Triticum aestivum) Actin1 (TaACT1), in planta. Following treatment of wheat, separately, with jasmonic acid, abscisic acid or with the avirulent race, CYR23, of the stripe rust pathogen Puccinia striiformis f. sp. tritici, we observed a rapid induction in accumulation of TaADF4 mRNA. Interestingly, accumulation of TaADF4 mRNA was diminished in response to inoculation with a virulent race, CYR31. Silencing of TaADF4 resulted in enhanced susceptibility to CYR23, demonstrating a role for TaADF4 in defense signaling. Using a pharmacological-based approach, coupled with an analysis of host response to pathogen infection, we observed that treatment of plants with the actin-modifying agent latrunculin B enhanced resistance to CYR23, including increased production of reactive oxygen species and enhancement of localized hypersensitive cell death. Taken together, these data support the hypothesis that TaADF4 positively modulates plant immunity in wheat via the modulation of actin cytoskeletal organization.
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A&F University, Yangling, Shaanxi, 712100, China.|Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI, 48824, USA.
authors.forename: Bing
authors.initials: B
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A&F University, Yangling, Shaanxi, 712100, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Hua
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A&F University, Yangling, Shaanxi, 712100, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A&F University, Yangling, Shaanxi, 712100, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Huo
authors.affiliation: Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI, 48824, USA.
authors.forename: Masaki
authors.initials: M
authors.lastname: Shimono
authors.affiliation: Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI, 48824, USA.|Plant Resilience Institute, Michigan State University, East Lansing, MI, 48824, USA.
authors.forename: Brad
authors.initials: B
authors.lastname: Day
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A&F University, Yangling, Shaanxi, 712100, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Ma
mesh_terms: D001487:Basidiomycota / Q000472:pathogenicity*; D003599:Cytoskeleton / Q000378:metabolism; D051345:Destrin / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant / Q000235:genetics / Q000502:physiology; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding / Q000235:genetics / Q000502:physiology; D014908:Triticum / Q000235:genetics / Q000378:metabolism* / Q000382:microbiology*
chemical_list: D051345:Destrin; D010940:Plant Proteins
keywords: 
  Triticum aestivum
  ; ADF4; Puccinia striiformis f. sp. tritici; actin; cytoskeleton; resistance; wheat