Regulation of acp1, encoding a non-aspartyl acid protease expressed during pathogenesis of Sclerotinia sclerotiorum

• Published in: Microbiology (Society for General Microbiology) Vol. 147; no. 3; pp. 717 - 726
• Main Authors: Poussereau, Nathalie, Creton, Sandrine, Billon-Grand, Genevieve, Rascle, Christine, Fevre, Michel
• Format: Journal Article
• Language: English
• Published: Reading Soc General Microbiol 01.03.2001; Society for General Microbiology
• Subjects: Amino Acid Sequence; Ammonia - metabolism; Ascomycota - enzymology; Ascomycota - pathogenicity; Aspartic Acid Endopeptidases - genetics; Aspartic Acid Endopeptidases - metabolism; Base Sequence; Biological and medical sciences; Cloning, Molecular; Endopeptidases - chemistry; Endopeptidases - genetics; Endopeptidases - metabolism; Fundamental and applied biological sciences. Psychology; Fungal plant pathogens; Fungal Proteins; Gene Expression Regulation, Fungal; Glucose - metabolism; Growth, nutrition, metabolism, transports, enzymes. Molecular biology; Helianthus - microbiology; Hydrogen-Ion Concentration; Microbiology; Molecular Sequence Data; Mycology; Phytopathology. Animal pests. Plant and forest protection; Plant Diseases - microbiology; Promoter Regions, Genetic - genetics; Sequence Analysis, DNA; Systematics. Morphology. Development cycle. Physiology; Transcription, Genetic; Plant pathogen; Nucleotide sequence; Enzyme; Medium without; Sclerotinia sclerotiorum; Acid proteinase; Glucose; Nitrogen; Gene expression; Carbon; Fungi; Pathogenicity; Peptidases; Regulation(control); Hydrolases; Ascomycetes; Aminoacid sequence; Thallophyta; Catabolic repression
• ISSN: 1350-0872; 1465-2080
• DOI: 10.1099/00221287-147-3-717

Laboratoire de Biologie Cellulaire Fongique (bât 405), ERS CNRS 2009, Microbiologie et Génétique, Université Claude Bernard-Lyon I, 43 Bd du 11 Novembre 1918, 69622 Villeurbanne cedex, France 1 Author for correspondence: Michel Fevre. Tel: +33 4 72 44 83 78. Fax: +33 4 72 43 11 81. e-mail: mfevre{at}biomserv.univ-lyon1.fr When grown in the presence of sunflower cell walls, Sclerotinia sclerotiorum , an ubiquitous necrotrophic fungus, secretes several acid proteases including a non-aspartyl protease. The gene acp1 , encoding an acid protease, has been cloned and sequenced. The intronless ORF encodes a preproprotein of 252 aa and a mature protein of 200 residues. In vitro expression of acp1 is subject to several transcriptional regulatory mechanisms. Expression induced by plant cell-wall proteins is controlled by both carbon and nitrogen catabolite repression. Glucose on its own represses acp1 expression while ammonium repression requires the simultaneous presence of a carbon source. Ambient pH higher than pH 5 overrides induction resulting in full repression of acp1 . These transcriptional regulatory mechanisms and the presence of several motifs in the promoter of acp1 that may encode binding sites for the regulators CREA, AREA and PacC suggest the involvement of these regulators in the control of acp1 expression . acp1 is expressed in planta during sunflower cotyledon infection. Expression is low at the beginning of infection but increases suddenly at the stage of necrosis spreading. Comparison of in vitro and in planta acp1 expression suggests that glucose and nitrogen starvation together with acidification can be considered as key factors controlling Scl. sclerotiorum gene expression during pathogenesis. Keywords: acid protease, gene expression, pH regulation, carbon and nitrogen repression, plant pathogenesis a Present address: Département de Biochimie Médicale, Centre Médical Universitaire, 1 rue Michel Servet -1211 Genève 4, Switzerland.