Elevated amino acid biosynthesis in Phytophthora infestans during appressorium formation and potato infection

Laura J. Grenville-Briggs, Anna O. Avrova, Catherine R. Bruce, Alison Williams, Stephen C. Whisson, Paul R. J. Birch, Pieter van West

Research output: Contribution to journalArticle

73 Citations (Scopus)

Abstract

Appressorium formation is believed to be an important event in establishing a successful interaction between the late blight pathogen, Phytophthora infestans, and its host plants potato and tomato. An understanding of molecular events occurring in appressorium development could Suggest new strategies for controlling late blight. We used parallel studies of the transcriptome and proteome to identify genes and proteins that are up-regulated in germinating cysts developing appressoria. As a result, five distinct genes involved in amino acid biosynthesis were identified that show increased expression in germinating cysts with appressoria. These are a methionine synthase (Pi-met1), a ketol-acid reductoisomerase (Pi-kari1), a tryptophan synthase (Pi-trp1), an acetolactate synthase (Pi-als1), and a threonine synthase (Pi-ts1). Four of these P. infestans genes were also up-regulated, although to lower levels, during the early, biotrophic phase of the interaction in potato and all five were considerably Up-regulated during the transition (48 hpi) to the necrotrophic phase of the interaction. Real-time RT-PCR revealed that expression of potato homologues of the amino acid biosynthesis genes increased during biotrophic and necrotrophic infection phases. Furthermore, we investigated levels of free amino acids in the pre-infection stages and found that in most cases there was a decrease in free amino acids in zoospores and germinating cysts, relative to sporangia, followed by a sharp increase in germinating cysts with appressoria. Amino acid biosynthesis Would appear to be important for pathogenicity in P. infestans, providing a potential metabolic tat-get for chemical control. (C) 2004 Elsevier Inc. All rights reserved.

Original languageEnglish
Pages (from-to)244-256
Number of pages12
JournalFungal Genetics and Biology
Volume42
Issue number3
Early online date11 Jan 2005
DOIs
Publication statusPublished - Mar 2005

Keywords

  • proteomics
  • SSH
  • real-time RT-PCR
  • oomycete
  • late blight
  • amino acid biosynthesis
  • pathogenicity
  • pathogen blumeria-graminis
  • fungus magnaporthe-grisea
  • insertional mutagenesis
  • hypersensitive response
  • gene-expression
  • nicotianae
  • identification
  • resistance
  • palmivora
  • proteins

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