title: Actin marker lines in grapevine reveal a gatekeeper function of guard cells.
abstract: Resistance to abiotic and biotic stress is a central topic for sustainable agriculture, especially in grapevine, one of the field crops with the highest economic output per acreage. As early cellular factors for plant defense, actin microfilaments (AF) are of high relevance. We therefore generated a transgenic actin marker line for grapevine by expressing a fusion protein between green fluorescent protein and the second actin-binding domain of Arabidopsis (Arabidopsis thaliana) fimbrin, AtFIM1. Based on this first cytoskeletal-marker line in grapevine, the response of AFs to phytopathogenic microorganisms could be followed in vivo. Upon inoculation with fluorescently labeled strains of phytopathogenic bacteria, actin responses were confined to the guard cells. In contrast, upon contact with zoospores of Plasmopara viticola, not only the guard cells, but also epidermal pavement cells, where no zoospores had attached responded with the formation of a perinuclear actin basket. Our data support the hypothesis that guard cells act as pacemakers of defense, dominating the responses of the remaining epidermal cells.
authors: Molecular Cell Biology, Botanical Institute, Karlsruhe Institute of Technology, Kaiserstraße 2, D-76128 Karlsruhe, Germany; College of Horticulture and Landscape Architecture, Southwest University, 400716 Chongqing, China. Electronic address: xinguan.cnde@googlemail.com.
authors: Xin
authors: X
authors: Guan
authors: RLP AgroScience/AlPlanta - Institute for Plant Research, Breitenweg 71, D-67435 Neustadt an der Weinstraße, Germany.
authors: Günther
authors: G
authors: Buchholz
authors: Molecular Cell Biology, Botanical Institute, Karlsruhe Institute of Technology, Kaiserstraße 2, D-76128 Karlsruhe, Germany.
authors: Peter
authors: P
authors: Nick
mesh_terms: D008841:Actin Cytoskeleton / Q000235:genetics / Q000378:metabolism; D000199:Actins / Q000235:genetics / Q000378:metabolism*; D017360:Arabidopsis / Q000235:genetics; D018556:Crops, Agricultural; D018506:Gene Expression Regulation, Plant; D017930:Genes, Reporter; D005819:Genetic Markers / Q000235:genetics; D006090:Gram-Negative Bacteria / Q000502:physiology*; D009868:Oomycetes / Q000502:physiology*; D010641:Phenotype; D010935:Plant Diseases / Q000276:immunology* / Q000382:microbiology; D019441:Plant Epidermis / Q000166:cytology / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D018515:Plant Leaves / Q000166:cytology / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D030821:Plants, Genetically Modified; D027843:Vitis / Q000166:cytology / Q000235:genetics* / Q000276:immunology / Q000378:metabolism
chemical_list: D000199:Actins; D005819:Genetic Markers
keywords: Actin; Gram-negative bacteria; Guard cell; Plasmopara viticola; Vitis vinifera ‘Chardonnay’, transgenic