title: A ConA-like lectin from Dioclea guianensis Benth. has antifungal activity against Colletotrichum gloeosporioides, unlike its homologues, ConM and ConA.
abstract: This study reports on the antifungal activity of Dgui, a ConA-like lectin from Dioclea guianensis seeds. Dgui inhibited conidial germination but not mycelial growth of Colletotrichum gloeosporioides. The lectins ConA and ConM from Canavalia ensiformis and Canavalia maritima, respectively, share high levels of amino acid sequence similarity (>84%) with Dgui and have the same specificity toward glucose/mannose but had no effect on the fungus. Fluorescence microscopy showed that both Dgui and ConM bind to C. gloeosporioides ungerminated conidia. However, Dgui did not bind to C. gloeosporioides germinated conidia and germ tubes and was not inhibitory to mycelial growth. Because only Dgui inhibited germination of the fungus, C. gloeosporioides conidia might have surface-specific germination targets recognized by Dgui but not by its homologues, ConM and ConA. Therefore, Dgui is a candidate for biotechnological approaches for improving the resistance of various nutritionally and commercially important crops that are affected by C. gloeosporioides.
authors.affiliation: Departamento de Bioquimica e Biologia Molecular, Universidade Federal do Ceara, Fortaleza, CE, CEP, Brazil.
authors.forename: José H
authors.initials: JH
authors.lastname: Araújo-Filho
authors.forename: Ilka M
authors.initials: IM
authors.lastname: Vasconcelos
authors.forename: Aparecida S
authors.initials: AS
authors.lastname: Martins-Miranda
authors.forename: Darcy M F
authors.initials: DM
authors.lastname: Gondim
authors.forename: José T A
authors.initials: JT
authors.lastname: Oliveira
mesh_terms: D000595:Amino Acid Sequence; D000935:Antifungal Agents / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology*; D020231:Colletotrichum / Q000187:drug effects* / Q000254:growth & development; D003208:Concanavalin A / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D052598:Dioclea / Q000737:chemistry / Q000378:metabolism*; D037102:Lectins / Q000737:chemistry / Q000191:economics / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology*; D008969:Molecular Sequence Data; D016415:Sequence Alignment
chemical_list: D000935:Antifungal Agents; D037102:Lectins; D003208:Concanavalin A