title: Gastrodianin-like mannose-binding proteins: a novel class of plant proteins with antifungal properties.
abstract: The orchid Gastrodia elata depends on the fungus Armillaria mellea to complete its life cycle. In the interaction, fungal hyphae penetrate older, nutritive corms but not newly formed corms. From these corms, a protein fraction with in vitro activity against plant-pathogenic fungi has previously been purified. Here, the sequence of gastrodianin, the main constituent of the antifungal fraction, is reported. Four isoforms that encoded two different mature proteins were identified at the cDNA level. Another isoform was detected in sequenced peptides. Because the antifungal activity of gastrodianins produced in and purified from Escherichia coli and Nicotiana tabacum was comparable to that of gastrodianin purified from the orchid, gastrodianins are the active component of the antifungal fractions. Gastrodianin accumulation is probably an important part of the mechanism by which the orchid controls Armillaria penetration. Gastrodianin was found to be homologous to monomeric mannose-binding proteins of other orchids, of which at least one (Epipactis helleborine mannose-binding protein) also displayed in vitro antifungal activity. This establishes the gastrodianin-like proteins (GLIPs) as a novel class of antifungal proteins.
authors.affiliation: Vakgroep Moleculaire Genetica en Departement Plantengenetica, Vlaams Interuniversitair Instituut voor Biotechnologie (VIB), Universiteit Gent, K.L. Ledeganckstraat 35, B-9000 Gent, Belgium.
authors.forename: X
authors.initials: X
authors.lastname: Wang
authors.forename: G
authors.initials: G
authors.lastname: Bauw
authors.forename: E J
authors.initials: EJ
authors.lastname: Van Damme
authors.forename: W J
authors.initials: WJ
authors.lastname: Peumans
authors.forename: Z L
authors.initials: ZL
authors.lastname: Chen
authors.forename: M
authors.initials: M
authors.lastname: Van Montagu
authors.forename: G
authors.initials: G
authors.lastname: Angenon
authors.forename: W
authors.initials: W
authors.lastname: Dillen
mesh_terms: D000595:Amino Acid Sequence; D000935:Antifungal Agents / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology*; D001483:Base Sequence; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology*; D003001:Cloning, Molecular; D037222:Collectins; D018076:DNA, Complementary / Q000302:isolation & purification; D018744:DNA, Plant; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D005658:Fungi / Q000187:drug effects* / Q000254:growth & development; D037102:Lectins / Q000235:genetics / Q000378:metabolism; D019684:Magnoliopsida / Q000235:genetics* / Q000378:metabolism; D008351:Mannans / Q000235:genetics / Q000378:metabolism; D008358:Mannose / Q000378:metabolism; D037241:Mannose-Binding Lectins; D013058:Mass Spectrometry; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D037121:Plant Lectins; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000494:pharmacology*; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D013559:Symbiosis
chemical_list: D000935:Antifungal Agents; D002352:Carrier Proteins; D037222:Collectins; D018076:DNA, Complementary; D018744:DNA, Plant; D037102:Lectins; D008351:Mannans; D037241:Mannose-Binding Lectins; D037121:Plant Lectins; D010940:Plant Proteins; D020033:Protein Isoforms; C437088:gastrodianin; D008358:Mannose