title: The Arabidopsis ROP-activated receptor-like cytoplasmic kinase RLCK VI_A3 is involved in control of basal resistance to powdery mildew and trichome branching.
abstract: The Arabidopsis receptor-like cytoplasmic kinase AtRLCK VI_A3 is activated by AtROPs and is involved in trichome branching and pathogen interaction. Receptor-like cytoplasmic kinases (RLCKs) belong to the large superfamily of receptor-like kinases, which are involved in a variety of cellular processes like plant growth, development and immune responses. Recent studies suggest that RLCKs of the VI_A subfamily are possible downstream effectors of the small monomeric G proteins of the plant-specific Rho family, called 'Rho of plants' (RAC/ROPs). Here, we describe Arabidopsis thaliana AtRLCK VI_A3 as a molecular interactor of AtROPs. In Arabidopsis epidermal cells, transient co-expression of plasma membrane located constitutively activated (CA) AtROP4 or CA AtROP6 resulting in the recruitment of green fluorescent protein-tagged AtRLCK VI_A3 to the cell periphery. Intrinsic kinase activity of AtRLCK VI_A3 was enhanced in the presence of CA AtROP6 in vitro and further suggested a functional interaction between the proteins. In the interaction of the biotrophic powdery mildew fungus Erysiphe cruciferarum (E. cruciferarum) and its host plant Arabidopsis, Atrlck VI_A3 mutant lines supported enhanced fungal reproduction. Furthermore Atrlck VI_A3 mutant lines showed slightly reduced size and an increase in trichome branch number compared to wild-type plants. In summary, our data suggest a role of the AtROP-regulated AtRLCK VI_A3 in basal resistance to E. cruciferarum as well as in plant growth and cellular differentiation during trichome morphogenesis. Results are discussed in the context of literature suggesting a function of RAC/ROPs in both resistance and susceptibility to pathogen infection.
authors.affiliation: Lehrstuhl für Phytopathologie, Technische Universität München, Emil-Ramann Straße 2, 85350, Freising-Weihenstephan, Germany.
authors.forename: Tina
authors.initials: T
authors.lastname: Reiner
authors.forename: Caroline
authors.initials: C
authors.lastname: Hoefle
authors.forename: Christina
authors.initials: C
authors.lastname: Huesmann
authors.forename: Dalma
authors.initials: D
authors.lastname: Ménesi
authors.forename: Attila
authors.initials: A
authors.lastname: Fehér
authors.forename: Ralph
authors.initials: R
authors.lastname: Hückelhoven
mesh_terms: D017360:Arabidopsis / Q000382:microbiology / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001203:Ascomycota / Q000472:pathogenicity; D060467:Disease Resistance; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D001467:Hordeum / Q000235:genetics / Q000378:metabolism; D054884:Host-Pathogen Interactions; D020559:Monomeric GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D010935:Plant Diseases / Q000382:microbiology; D030821:Plants, Genetically Modified; D064201:Trichomes / Q000254:growth & development / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; C518506:ROP6 protein, Arabidopsis; D049452:Green Fluorescent Proteins; D020559:Monomeric GTP-Binding Proteins