title: Defence-related gene activation during an incompatible interaction between Stagonospora (Septoria) nodorum and barley (Hordeum vulgare L.) coleoptile cells.
abstract: Two previously unidentified cDNA clones (bsi1 and bpr1-1) were isolated by differential hybridization from a cDNA library of Stagonospora (Septoria) nodorum (Berk) Castellani & E.G. Germano (teleomorph Phaeosphaeria (Leptosphaeria) nodorum (E. Muller) Hedjaroude-challenged barley (Hordeum vulgare L.) coleoptiles. bsi1 encoded a cysteine-rich protein containing 89 amino acids (aa) with a relative molecular mass (M(r)) of 9405. Protein sequence homologies showed that Bsi1 was very similar to an aluminium-induced protein from wheat and indicated that it was related to the Bowman-Birk-type proteinase inhibitors (BB-PIs). The predicted aa sequence of Bsi1 contained an N-terminal secretory signal sequence which implied that the protein was exported. The other clone, bprl-1, which was truncated at the 5' end, encoded a type-1 pathogenesis-related (PR-1) protein. The complete sequence of bpr1-1 was obtained after cloning a barley genomic DNA fragment and was shown to encode a basic protein containing 174 aa with a M(r) of 18 859. The deduced aa sequence of bpr1-1 contained both an N-terminal secretory signal sequence and a charged C-terminal extension. This latter sequence may represent a vacuolar targeting signal. bsil and bpr1-1 and four other defence-related genes (encoding 1,3-beta-glucanase, 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase, a homologue of a putative wheat peroxidase, and barley leaf-specific thionin), showed increased transcription levels in S. nodorum-challenged coleoptiles, although their pattern of accumulation varied after inoculation (a.i.). The potential role of these induced genes in defence against fungal attack is discussed.
authors.affiliation: Department of Plant Sciences, University of Oxford, UK.
authors.forename: C
authors.initials: C
authors.lastname: Stevens
authors.forename: E
authors.initials: E
authors.lastname: Titarenko
authors.forename: J A
authors.initials: JA
authors.lastname: Hargreaves
authors.forename: S J
authors.initials: SJ
authors.lastname: Gurr
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D018548:Cotyledon / Q000382:microbiology; D018076:DNA, Complementary / Q000235:genetics; D018506:Gene Expression Regulation, Plant / Q000502:physiology*; D017343:Genes, Plant / Q000235:genetics; D001467:Hordeum / Q000235:genetics* / Q000382:microbiology; D003904:Mitosporic Fungi / Q000254:growth & development / Q000472:pathogenicity*; D008969:Molecular Sequence Data; D010935:Plant Diseases; D010940:Plant Proteins / Q000235:genetics*; D012333:RNA, Messenger / Q000032:analysis; D018749:RNA, Plant / Q000032:analysis; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D015533:Transcriptional Activation
chemical_list: C101502:Bpr1-1 protein, Hordeum vulgare; C101501:Bsi1 protein, Hordeum vulgare; D018076:DNA, Complementary; D010940:Plant Proteins; D012333:RNA, Messenger; D018749:RNA, Plant; C053376:pathogenesis-related proteins, plant