title: The compromised recognition of turnip crinkle virus1 subfamily of microrchidia ATPases regulates disease resistance in barley to biotrophic and necrotrophic pathogens.
abstract: MORC1 and MORC2, two of the seven members of the Arabidopsis (Arabidopsis thaliana) Compromised Recognition of Turnip Crinkle Virus1 subfamily of microrchidia Gyrase, Heat Shock Protein90, Histidine Kinase, MutL (GHKL) ATPases, were previously shown to be required in multiple layers of plant immunity. Here, we show that the barley (Hordeum vulgare) MORCs also are involved in disease resistance. Genome-wide analyses identified five MORCs that are 37% to 48% identical on the protein level to AtMORC1. Unexpectedly, and in clear contrast to Arabidopsis, RNA interference-mediated knockdown of MORC in barley resulted in enhanced basal resistance and effector-triggered, powdery mildew resistance locus A12-mediated resistance against the biotrophic powdery mildew fungus (Blumeria graminis f. sp. hordei), while MORC overexpression decreased resistance. Moreover, barley knockdown mutants also showed higher resistance to Fusarium graminearum. Barley MORCs, like their Arabidopsis homologs, contain the highly conserved GHKL ATPase and S5 domains, which identify them as members of the MORC superfamily. Like AtMORC1, barley MORC1 (HvMORC1) binds DNA and has Mn2+-dependent endonuclease activities, suggesting that the contrasting function of MORC1 homologs in barley versus Arabidopsis is not due to differences in their enzyme activities. In contrast to AtMORCs, which are involved in silencing of transposons that are largely restricted to pericentromeric regions, barley MORC mutants did not show a loss-of-transposon silencing regardless of their genomic location. Reciprocal overexpression of MORC1 homologs in barley and Arabidopsis showed that AtMORC1 and HvMORC1 could not restore each other's function. Together, these results suggest that MORC proteins function as modulators of immunity, which can act negatively (barley) or positively (Arabidopsis) dependent on the species.
authors.affiliation: Research Centre for BioSystems, Land Use, and Nutrition , Justus Liebig University, 35392 Giessen, Germany.
authors.forename: Gregor
authors.initials: G
authors.lastname: Langen
authors.forename: Sabrina
authors.initials: S
authors.lastname: von Einem
authors.forename: Aline
authors.initials: A
authors.lastname: Koch
authors.forename: Jafargholi
authors.initials: J
authors.lastname: Imani
authors.forename: Subhash B
authors.initials: SB
authors.lastname: Pai
authors.forename: Murli
authors.initials: M
authors.lastname: Manohar
authors.forename: Katrin
authors.initials: K
authors.lastname: Ehlers
authors.forename: Hyong Woo
authors.initials: HW
authors.lastname: Choi
authors.forename: Martina
authors.initials: M
authors.lastname: Claar
authors.forename: Rebekka
authors.initials: R
authors.lastname: Schmidt
authors.forename: Hyung-Gon
authors.initials: HG
authors.lastname: Mang
authors.forename: Yogendra
authors.initials: Y
authors.lastname: Bordiya
authors.forename: Hong-Gu
authors.initials: HG
authors.lastname: Kang
authors.forename: Daniel F
authors.initials: DF
authors.lastname: Klessig
authors.forename: Karl-Heinz
authors.initials: KH
authors.lastname: Kogel
mesh_terms: D000251:Adenosine Triphosphatases / Q000737:chemistry / Q000378:metabolism* / Q000648:ultrastructure; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000276:immunology / Q000382:microbiology / Q000648:ultrastructure; D001203:Ascomycota; D020171:Botrytis / Q000502:physiology; D019184:Carmovirus / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism / Q000648:ultrastructure; D004251:DNA Transposable Elements / Q000235:genetics; D018744:DNA, Plant / Q000378:metabolism; D060467:Disease Resistance / Q000276:immunology*; D005670:Fusarium / Q000502:physiology; D018506:Gene Expression Regulation, Plant; D020868:Gene Silencing; D017343:Genes, Plant / Q000235:genetics; D001467:Hordeum / Q000201:enzymology* / Q000235:genetics / Q000276:immunology* / Q000382:microbiology; D008969:Molecular Sequence Data; D010802:Phylogeny; D010935:Plant Diseases / Q000276:immunology / Q000382:microbiology*; D057865:Plant Immunity / Q000235:genetics; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified; D011485:Protein Binding; D044224:Pseudomonas syringae / Q000502:physiology; D012689:Sequence Homology, Nucleic Acid
chemical_list: D004251:DNA Transposable Elements; D018744:DNA, Plant; D010940:Plant Proteins; D000251:Adenosine Triphosphatases