title: Functional analysis of a Wheat Homeodomain protein, TaR1, reveals that host chromatin remodelling influences the dynamics of the switch to necrotrophic growth in the phytopathogenic fungus Zymoseptoria tritici.
abstract: A distinguishing feature of Septoria leaf blotch disease in wheat is the long symptomless growth of the fungus amongst host cells followed by a rapid transition to necrotrophic growth resulting in disease lesions. Global reprogramming of host transcription marks this switch to necrotrophic growth. However no information exists on the components that bring about host transcriptional reprogramming. Gene-silencing, confocal-imaging and protein-protein interaction assays where employed to identify a plant homeodomain (PHD) protein, TaR1 in wheat that plays a critical role during the transition from symptomless to necrotrophic growth of Septoria. TaR1-silenced wheat show earlier symptom development upon Septoria infection but reduced fungal sporulation indicating that TaR1 is key for prolonging the symptomless phase and facilitating Septoria asexual reproduction. TaR1 is localized to the nucleus and binds to wheat Histone 3. Trimethylation of Histone 3 at lysine 4 (H3K4) and lysine 36 (H3K36) are found on open chromatin with actively transcribed genes, whereas methylation of H3K27 and H3K9 are associated with repressed loci. TaR1 specifically recognizes dimethylated and trimethylated H3K4 peptides suggesting that it regulates transcriptional activation at open chromatin. We conclude that TaR1 is an important component for the pathogen life cycle in wheat that promotes successful colonization by Septoria.
authors: Durham Centre for Crop Improvement Technology, School of Biology and Biomedical Sciences, University of Durham, Durham, DH1 3LE, UK.
authors: Jack
authors: J
authors: Lee
authors: Beatriz
authors: B
authors: Orosa
authors: Linda
authors: L
authors: Millyard
authors: Martin
authors: M
authors: Edwards
authors: Kostya
authors: K
authors: Kanyuka
authors: Angharad
authors: A
authors: Gatehouse
authors: Jason
authors: J
authors: Rudd
authors: Kim
authors: K
authors: Hammond-Kosack
authors: Naomi
authors: N
authors: Pain
authors: Ari
authors: A
authors: Sadanandom
mesh_terms: D000595:Amino Acid Sequence; D001203:Ascomycota / Q000254:growth & development / Q000502:physiology*; D042002:Chromatin Assembly and Disassembly; D018556:Crops, Agricultural; D015966:Gene Expression Regulation, Fungal; D018506:Gene Expression Regulation, Plant; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism*; D054884:Host-Pathogen Interactions; D008969:Molecular Sequence Data; D010802:Phylogeny; D010935:Plant Diseases / Q000382:microbiology*; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism / Q000382:microbiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D014908:Triticum / Q000235:genetics* / Q000378:metabolism / Q000382:microbiology
chemical_list: D018398:Homeodomain Proteins; D010940:Plant Proteins
keywords: chromatin remodelling; crops; plant homeodomain; plant pathogen; septoria