title: Colletotrichum orbiculare Regulates Cell Cycle G1/S Progression via a Two-Component GAP and a GTPase to Establish Plant Infection.
abstract: Morphogenesis in filamentous fungi depends on appropriate cell cycle progression. Here, we report that cells of the cucumber anthracnose fungus Colletotrichum orbiculare regulate G1/S progression via a two-component GAP, consisting of Budding-uninhibited-by-benomyl-2 (Bub2) and Byr-four-alike-1 (Bfa1) as well as its GTPase Termination-of-M-phase-1 (Tem1) to establish successful infection. In a random insertional mutagenesis screen of infection-related morphogenesis, we isolated a homolog of Saccharomyces cerevisiae, BUB2, which encodes a two-component Rab GAP protein that forms a GAP complex with Bfa1p and negatively regulates mitotic exit. Interestingly, disruption of either Co BUB2 or Co BFA1 resulted in earlier onset of nuclear division and decreased the time of phase progression from G1 to S during appressorium development. S. cerevisiae GTPase Tem1p is the downstream target of the Bub2p/Bfa1p GAP complex. Introducing the dominant-negative form of Co Tem1 into Co bub2Δ or Co bfa1Δ complemented the defect in G1/S progression, indicating that Co Bub2/Co Bfa1 regulates G1/S progression via Co Tem1. Based on a pathogenicity assay, we found that Co bub2Δ and Co bfa1Δ reduced pathogenesis by attenuating infection-related morphogenesis and enhancing the plant defense response. Thus, during appressorium development, C. orbiculare Bub2/Bfa1 regulates G1/S progression via Co Tem1, and this regulation is essential to establish plant infection.
authors: Laboratory of Plant Pathology, Life and Environmental Sciences, Graduate School of Kyoto Prefectural University, Kyoto 606-8522, Japan.
authors: Fumi
authors: http://orcid.org/0000-0002-6815-9929
authors: F
authors: Fukada
authors: Laboratory of Plant Pathology, Life and Environmental Sciences, Graduate School of Kyoto Prefectural University, Kyoto 606-8522, Japan y_kubo@kpu.ac.jp.
authors: Yasuyuki
authors: http://orcid.org/0000-0002-8600-9705
authors: Y
authors: Kubo
mesh_terms: D002453:Cell Cycle; D018797:Cell Cycle Proteins / Q000378:metabolism; D020231:Colletotrichum / Q000235:genetics / Q000378:metabolism / Q000472:pathogenicity*; D018553:Cucumis sativus / Q000166:cytology / Q000382:microbiology*; D003598:Cytoskeletal Proteins / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D020690:GTPase-Activating Proteins / Q000235:genetics / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D054884:Host-Pathogen Interactions; D008969:Molecular Sequence Data; D020559:Monomeric GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism; D046912:Multiprotein Complexes; D016254:Mutagenesis, Insertional; D010935:Plant Diseases / Q000382:microbiology*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: C119117:BFA1 protein, S cerevisiae; C070351:BUB2 protein, S cerevisiae; D018797:Cell Cycle Proteins; D003598:Cytoskeletal Proteins; D005656:Fungal Proteins; D020690:GTPase-Activating Proteins; D046912:Multiprotein Complexes; D029701:Saccharomyces cerevisiae Proteins; C089965:TEM1 protein, S cerevisiae; D020559:Monomeric GTP-Binding Proteins