title: Gene expression profiling during asexual development of the late blight pathogen Phytophthora infestans reveals a highly dynamic transcriptome.
abstract: Much of the pathogenic success of Phytophthora infestans, the potato and tomato late blight agent, relies on its ability to generate from mycelia large amounts of sporangia, which release zoospores that encyst and form infection structures. To better understand these stages, Affymetrix GeneChips based on 15,650 unigenes were designed and used to profile the life cycle. Approximately half of P. infestans genes were found to exhibit significant differential expression between developmental transitions, with approximately (1)/(10) being stage-specific and most changes occurring during zoosporogenesis. Quantitative reverse-transcription polymerase chain reaction assays confirmed the robustness of the array results and showed that similar patterns of differential expression were obtained regardless of whether hyphae were from laboratory media or infected tomato. Differentially expressed genes encode potential cellular regulators, especially protein kinases; metabolic enzymes such as those involved in glycolysis, gluconeogenesis, or the biosynthesis of amino acids or lipids; regulators of DNA synthesis; structural proteins, including predicted flagellar proteins; and pathogenicity factors, including cell-wall-degrading enzymes, RXLR effector proteins, and enzymes protecting against plant defense responses. Curiously, some stage-specific transcripts do not appear to encode functional proteins. These findings reveal many new aspects of oomycete biology, as well as potential targets for crop protection chemicals.
authors.affiliation: Department of Plant Pathology and Microbiology, University of California, Riverside 92521, USA. howard.judelson@ucr.edu
authors.forename: Howard S
authors.initials: HS
authors.lastname: Judelson
authors.forename: Audrey M V
authors.initials: AM
authors.lastname: Ah-Fong
authors.forename: George
authors.initials: G
authors.lastname: Aux
authors.forename: Anna O
authors.initials: AO
authors.lastname: Avrova
authors.forename: Catherine
authors.initials: C
authors.lastname: Bruce
authors.forename: Cahid
authors.initials: C
authors.lastname: Cakir
authors.forename: Luis
authors.initials: L
authors.lastname: da Cunha
authors.forename: Laura
authors.initials: L
authors.lastname: Grenville-Briggs
authors.forename: Maita
authors.initials: M
authors.lastname: Latijnhouwers
authors.forename: Wilco
authors.initials: W
authors.lastname: Ligterink
authors.forename: Harold J G
authors.initials: HJ
authors.lastname: Meijer
authors.forename: Samuel
authors.initials: S
authors.lastname: Roberts
authors.forename: Carrie S
authors.initials: CS
authors.lastname: Thurber
authors.forename: Stephen C
authors.initials: SC
authors.lastname: Whisson
authors.forename: Paul R J
authors.initials: PR
authors.lastname: Birch
authors.forename: Francine
authors.initials: F
authors.lastname: Govers
authors.forename: Sophien
authors.initials: S
authors.lastname: Kamoun
authors.forename: Pieter
authors.initials: P
authors.lastname: van West
authors.forename: John
authors.initials: J
authors.lastname: Windass
mesh_terms: D020869:Gene Expression Profiling / Q000379:methods*; D008954:Models, Biological; D020411:Oligonucleotide Array Sequence Analysis; D010838:Phytophthora / Q000235:genetics* / Q000254:growth & development*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014158:Transcription, Genetic