An aspartic proteinase gene family in the filamentous fungus Botrytis cinerea contains members with novel features.
Botrytis cinerea, an important fungal plant pathogen, secretes aspartic proteinase (AP) activity in axenic cultures. No cysteine, serine or metalloproteinase activity could be detected. Proteinase activity was higher in culture medium containing BSA or wheat germ extract, as compared to minimal medium. A proportion of the enzyme activity remained in the extracellular glucan sheath. AP was also the only type of proteinase activity in fluid obtained from B. cinerea-infected tissue of apple, pepper, tomato and zucchini. Five B. cinerea genes encoding an AP were cloned and denoted Bcap1-5. Features of the encoded proteins are discussed. BcAP1, especially, has novel characteristics. A phylogenetic analysis was performed comprising sequences originating from different kingdoms. BcAP1 and BcAP5 did not cluster in a bootstrap-supported clade. BcAP2 clusters with vacuolar APs. BcAP3 and BcAP4 cluster with secreted APs in a clade that also contains glycosylphosphatidylinositol-anchored proteinases from Saccharomyces cerevisiae and Candida albicans. All five Bcap genes are expressed in liquid cultures. Transcript levels of Bcap1, Bcap2, Bcap3 and Bcap4 are subject to glucose and peptone repression. Transcripts from all five Bcap genes were detected in infected plant tissue, indicating that at least part of the AP activity in planta originates from the pathogen.
Ten Have
Arjen
A
Laboratory of Phytopathology, Wageningen University, Binnenhaven 5, PO Box 8025, 6700 EE Wageningen, The Netherlands.
Dekkers
Ester
E
Laboratory of Phytopathology, Wageningen University, Binnenhaven 5, PO Box 8025, 6700 EE Wageningen, The Netherlands.
Kay
John
J
Cardiff School of Biosciences, Cardiff University, PO Box 911, Cardiff CF10 3US, UK.
Phylip
Lowri H
LH
Cardiff School of Biosciences, Cardiff University, PO Box 911, Cardiff CF10 3US, UK.
van Kan
Jan A L
JAL
Laboratory of Phytopathology, Wageningen University, Binnenhaven 5, PO Box 8025, 6700 EE Wageningen, The Netherlands.
D000595:Amino Acid Sequence; D016282:Aspartic Acid Endopeptidases / Q000235:genetics* / Q000378:metabolism; D020171:Botrytis / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D003001:Cloning, Molecular; D003470:Culture Media; D015966:Gene Expression Regulation, Fungal; D027845:Malus / Q000382:microbiology; D008969:Molecular Sequence Data; D005810:Multigene Family; D010802:Phylogeny; D010935:Plant Diseases / Q000382:microbiology*; D017422:Sequence Analysis, DNA; D014675:Vegetables / Q000382:microbiology
D003470:Culture Media; D016282:Aspartic Acid Endopeptidases