title: RXLR Effector AVR2 Up-Regulates a Brassinosteroid-Responsive bHLH Transcription Factor to Suppress Immunity.
abstract: An emerging area in plant research focuses on antagonism between regulatory systems governing growth and immunity. Such cross talk represents a point of vulnerability for pathogens to exploit. AVR2, an RXLR effector secreted by the potato blight pathogenPhytophthora infestans, interacts with potato BSL1, a putative phosphatase implicated in growth-promoting brassinosteroid (BR) hormone signaling. Transgenic potato (Solanum tuberosum) plants expressing the effector exhibit transcriptional and phenotypic hallmarks of overactive BR signaling and show enhanced susceptibility toP. infestansMicroarray analysis was used to identify a set of BR-responsive marker genes in potato, all of which are constitutively expressed to BR-induced levels in AVR2 transgenic lines. One of these genes was a bHLH transcription factor, designatedStCHL1, homologous toAtCIB1andAtHBI1, which are known to facilitate antagonism between BR and immune responses. Transient expression of either AVR2 or CHL1 enhanced leaf colonization byP. infestansand compromised immune cell death activated by perception of the elicitin Infestin1 (INF1). Knockdown ofCHL1transcript using Virus-Induced Gene Silencing (VIGS) reduced colonization ofP. infestansonNicotiana benthamianaMoreover, the ability of AVR2 to suppress INF1-triggered cell death was attenuated inNbCHL1-silenced plants, indicating that NbCHL1 was important for this effector activity. Thus, AVR2 exploits cross talk between BR signaling and innate immunity inSolanumspecies, representing a novel, indirect mode of innate immune suppression by a filamentous pathogen effector.
authors.affiliation: Cell and Molecular Science, James Hutton Institute (D.T., L.Y., S.N., L.W., J.S., J.M., P.C.B., P.E.H., P.R.J.B., E.M.G.), and Division of Plant Science, School of Life Science (at The James Hutton institute) (D.T., L.Y., S.N., P.R.J.B.), University of Dundee Invergowrie, Dundee, DD2 5DA, United Kingdom.|Fujian Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agricultural and Forestry University, Fuzhou, Fujian 350002, China (L.Y., J.Z.).|James Hutton Ltd (at The James Hutton Institute), Plant Sciences Division, Research School of Biology, The Australian National University, Canberra 2601, Australia (S.B.); and.|Effector Consortium, James Hutton Institute, Invergowrie, Dundee DD2 5DA, United Kingdom (D.T., L.Y., S.N., L.W., P.C.B., P.E.H., P.R.J.B., E.M.G.).
authors.forename: Dionne
authors.initials: D
authors.lastname: Turnbull
authors.affiliation: Cell and Molecular Science, James Hutton Institute (D.T., L.Y., S.N., L.W., J.S., J.M., P.C.B., P.E.H., P.R.J.B., E.M.G.), and Division of Plant Science, School of Life Science (at The James Hutton institute) (D.T., L.Y., S.N., P.R.J.B.), University of Dundee Invergowrie, Dundee, DD2 5DA, United Kingdom.|Fujian Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agricultural and Forestry University, Fuzhou, Fujian 350002, China (L.Y., J.Z.).|James Hutton Ltd (at The James Hutton Institute), Plant Sciences Division, Research School of Biology, The Australian National University, Canberra 2601, Australia (S.B.); and.|Effector Consortium, James Hutton Institute, Invergowrie, Dundee DD2 5DA, United Kingdom (D.T., L.Y., S.N., L.W., P.C.B., P.E.H., P.R.J.B., E.M.G.).
authors.forename: Lina
authors.initials: L
authors.lastname: Yang
authors.affiliation: Cell and Molecular Science, James Hutton Institute (D.T., L.Y., S.N., L.W., J.S., J.M., P.C.B., P.E.H., P.R.J.B., E.M.G.), and Division of Plant Science, School of Life Science (at The James Hutton institute) (D.T., L.Y., S.N., P.R.J.B.), University of Dundee Invergowrie, Dundee, DD2 5DA, United Kingdom.|Fujian Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agricultural and Forestry University, Fuzhou, Fujian 350002, China (L.Y., J.Z.).|James Hutton Ltd (at The James Hutton Institute), Plant Sciences Division, Research School of Biology, The Australian National University, Canberra 2601, Australia (S.B.); and.|Effector Consortium, James Hutton Institute, Invergowrie, Dundee DD2 5DA, United Kingdom (D.T., L.Y., S.N., L.W., P.C.B., P.E.H., P.R.J.B., E.M.G.).
authors.forename: Shaista
authors.initials: S
authors.lastname: Naqvi
authors.affiliation: Cell and Molecular Science, James Hutton Institute (D.T., L.Y., S.N., L.W., J.S., J.M., P.C.B., P.E.H., P.R.J.B., E.M.G.), and Division of Plant Science, School of Life Science (at The James Hutton institute) (D.T., L.Y., S.N., P.R.J.B.), University of Dundee Invergowrie, Dundee, DD2 5DA, United Kingdom.|Fujian Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agricultural and Forestry University, Fuzhou, Fujian 350002, China (L.Y., J.Z.).|James Hutton Ltd (at The James Hutton Institute), Plant Sciences Division, Research School of Biology, The Australian National University, Canberra 2601, Australia (S.B.); and.|Effector Consortium, James Hutton Institute, Invergowrie, Dundee DD2 5DA, United Kingdom (D.T., L.Y., S.N., L.W., P.C.B., P.E.H., P.R.J.B., E.M.G.).
authors.forename: Susan
authors.initials: S
authors.lastname: Breen
authors.affiliation: Cell and Molecular Science, James Hutton Institute (D.T., L.Y., S.N., L.W., J.S., J.M., P.C.B., P.E.H., P.R.J.B., E.M.G.), and Division of Plant Science, School of Life Science (at The James Hutton institute) (D.T., L.Y., S.N., P.R.J.B.), University of Dundee Invergowrie, Dundee, DD2 5DA, United Kingdom.|Fujian Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agricultural and Forestry University, Fuzhou, Fujian 350002, China (L.Y., J.Z.).|James Hutton Ltd (at The James Hutton Institute), Plant Sciences Division, Research School of Biology, The Australian National University, Canberra 2601, Australia (S.B.); and.|Effector Consortium, James Hutton Institute, Invergowrie, Dundee DD2 5DA, United Kingdom (D.T., L.Y., S.N., L.W., P.C.B., P.E.H., P.R.J.B., E.M.G.).
authors.forename: Lydia
authors.initials: L
authors.lastname: Welsh
authors.affiliation: Cell and Molecular Science, James Hutton Institute (D.T., L.Y., S.N., L.W., J.S., J.M., P.C.B., P.E.H., P.R.J.B., E.M.G.), and Division of Plant Science, School of Life Science (at The James Hutton institute) (D.T., L.Y., S.N., P.R.J.B.), University of Dundee Invergowrie, Dundee, DD2 5DA, United Kingdom.|Fujian Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agricultural and Forestry University, Fuzhou, Fujian 350002, China (L.Y., J.Z.).|James Hutton Ltd (at The James Hutton Institute), Plant Sciences Division, Research School of Biology, The Australian National University, Canberra 2601, Australia (S.B.); and.|Effector Consortium, James Hutton Institute, Invergowrie, Dundee DD2 5DA, United Kingdom (D.T., L.Y., S.N., L.W., P.C.B., P.E.H., P.R.J.B., E.M.G.).
authors.forename: Jennifer
authors.initials: J
authors.lastname: Stephens
authors.affiliation: Cell and Molecular Science, James Hutton Institute (D.T., L.Y., S.N., L.W., J.S., J.M., P.C.B., P.E.H., P.R.J.B., E.M.G.), and Division of Plant Science, School of Life Science (at The James Hutton institute) (D.T., L.Y., S.N., P.R.J.B.), University of Dundee Invergowrie, Dundee, DD2 5DA, United Kingdom.|Fujian Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agricultural and Forestry University, Fuzhou, Fujian 350002, China (L.Y., J.Z.).|James Hutton Ltd (at The James Hutton Institute), Plant Sciences Division, Research School of Biology, The Australian National University, Canberra 2601, Australia (S.B.); and.|Effector Consortium, James Hutton Institute, Invergowrie, Dundee DD2 5DA, United Kingdom (D.T., L.Y., S.N., L.W., P.C.B., P.E.H., P.R.J.B., E.M.G.).
authors.forename: Jenny
authors.initials: J
authors.lastname: Morris
authors.affiliation: Cell and Molecular Science, James Hutton Institute (D.T., L.Y., S.N., L.W., J.S., J.M., P.C.B., P.E.H., P.R.J.B., E.M.G.), and Division of Plant Science, School of Life Science (at The James Hutton institute) (D.T., L.Y., S.N., P.R.J.B.), University of Dundee Invergowrie, Dundee, DD2 5DA, United Kingdom.|Fujian Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agricultural and Forestry University, Fuzhou, Fujian 350002, China (L.Y., J.Z.).|James Hutton Ltd (at The James Hutton Institute), Plant Sciences Division, Research School of Biology, The Australian National University, Canberra 2601, Australia (S.B.); and.|Effector Consortium, James Hutton Institute, Invergowrie, Dundee DD2 5DA, United Kingdom (D.T., L.Y., S.N., L.W., P.C.B., P.E.H., P.R.J.B., E.M.G.).
authors.forename: Petra C
authors.identifier: http://orcid.org/0000-0002-7021-9097
authors.initials: PC
authors.lastname: Boevink
authors.affiliation: Cell and Molecular Science, James Hutton Institute (D.T., L.Y., S.N., L.W., J.S., J.M., P.C.B., P.E.H., P.R.J.B., E.M.G.), and Division of Plant Science, School of Life Science (at The James Hutton institute) (D.T., L.Y., S.N., P.R.J.B.), University of Dundee Invergowrie, Dundee, DD2 5DA, United Kingdom.|Fujian Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agricultural and Forestry University, Fuzhou, Fujian 350002, China (L.Y., J.Z.).|James Hutton Ltd (at The James Hutton Institute), Plant Sciences Division, Research School of Biology, The Australian National University, Canberra 2601, Australia (S.B.); and.|Effector Consortium, James Hutton Institute, Invergowrie, Dundee DD2 5DA, United Kingdom (D.T., L.Y., S.N., L.W., P.C.B., P.E.H., P.R.J.B., E.M.G.).
authors.forename: Pete E
authors.identifier: http://orcid.org/0000-0003-0866-324X
authors.initials: PE
authors.lastname: Hedley
authors.affiliation: Cell and Molecular Science, James Hutton Institute (D.T., L.Y., S.N., L.W., J.S., J.M., P.C.B., P.E.H., P.R.J.B., E.M.G.), and Division of Plant Science, School of Life Science (at The James Hutton institute) (D.T., L.Y., S.N., P.R.J.B.), University of Dundee Invergowrie, Dundee, DD2 5DA, United Kingdom.|Fujian Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agricultural and Forestry University, Fuzhou, Fujian 350002, China (L.Y., J.Z.).|James Hutton Ltd (at The James Hutton Institute), Plant Sciences Division, Research School of Biology, The Australian National University, Canberra 2601, Australia (S.B.); and.|Effector Consortium, James Hutton Institute, Invergowrie, Dundee DD2 5DA, United Kingdom (D.T., L.Y., S.N., L.W., P.C.B., P.E.H., P.R.J.B., E.M.G.).
authors.forename: Jiasui
authors.initials: J
authors.lastname: Zhan
authors.affiliation: Cell and Molecular Science, James Hutton Institute (D.T., L.Y., S.N., L.W., J.S., J.M., P.C.B., P.E.H., P.R.J.B., E.M.G.), and Division of Plant Science, School of Life Science (at The James Hutton institute) (D.T., L.Y., S.N., P.R.J.B.), University of Dundee Invergowrie, Dundee, DD2 5DA, United Kingdom.|Fujian Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agricultural and Forestry University, Fuzhou, Fujian 350002, China (L.Y., J.Z.).|James Hutton Ltd (at The James Hutton Institute), Plant Sciences Division, Research School of Biology, The Australian National University, Canberra 2601, Australia (S.B.); and.|Effector Consortium, James Hutton Institute, Invergowrie, Dundee DD2 5DA, United Kingdom (D.T., L.Y., S.N., L.W., P.C.B., P.E.H., P.R.J.B., E.M.G.).
authors.forename: Paul R J
authors.initials: PRJ
authors.lastname: Birch
authors.affiliation: Cell and Molecular Science, James Hutton Institute (D.T., L.Y., S.N., L.W., J.S., J.M., P.C.B., P.E.H., P.R.J.B., E.M.G.), and Division of Plant Science, School of Life Science (at The James Hutton institute) (D.T., L.Y., S.N., P.R.J.B.), University of Dundee Invergowrie, Dundee, DD2 5DA, United Kingdom; eleanor.gilroy@hutton.ac.uk.|Fujian Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agricultural and Forestry University, Fuzhou, Fujian 350002, China (L.Y., J.Z.); eleanor.gilroy@hutton.ac.uk.|James Hutton Ltd (at The James Hutton Institute), Plant Sciences Division, Research School of Biology, The Australian National University, Canberra 2601, Australia (S.B.); and eleanor.gilroy@hutton.ac.uk.|Effector Consortium, James Hutton Institute, Invergowrie, Dundee DD2 5DA, United Kingdom (D.T., L.Y., S.N., L.W., P.C.B., P.E.H., P.R.J.B., E.M.G.) eleanor.gilroy@hutton.ac.uk.
authors.forename: Eleanor M
authors.identifier: http://orcid.org/0000-0002-5301-4268
authors.initials: EM
authors.lastname: Gilroy
mesh_terms: D000595:Amino Acid Sequence; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism*; D060406:Brassinosteroids / Q000378:metabolism; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D054884:Host-Pathogen Interactions / Q000235:genetics; D055750:Phytophthora infestans / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology; D057865:Plant Immunity / Q000235:genetics; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified; D017386:Sequence Homology, Amino Acid; D011198:Solanum tuberosum / Q000235:genetics / Q000378:metabolism* / Q000382:microbiology; D015854:Up-Regulation; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D060406:Brassinosteroids; D010940:Plant Proteins; D037521:Virulence Factors