title: Endophytic fungal beta-1,6-glucanase expression in the infected host grass.
abstract: Mutualistic fungal endophytes infect many grass species and often confer benefits to the hosts such as reduced herbivory by insects and animals. The physiological interactions between the endophytes and their hosts have not been well characterized. Fungal-secreted proteins are likely to be important components of the interaction. In the interaction between Poa ampla and the endophyte Neotyphodium sp., a fungal beta-1,6-glucanase is secreted into the apoplast, and activity of the enzyme is detectable in endophyte-infected plants. Sequence analysis indicates the beta-1,6-glucanase is homologous to enzymes secreted by the mycoparasitic fungi Trichoderma harzianum and Trichoderma virens. DNA gel-blot analysis indicated the beta-1,6-glucanase was encoded by a single gene. As a secreted protein, the beta-1,6-glucanase may have a nutritional role for the fungus. In culture, beta-1,6-glucanase activity was induced in the presence of beta-1,6-glucans. From RNA gel blots, similar beta-1,6-glucanases were expressed in tall fescue (Festuca arundinacea Schreb.) and Chewings fescue (Festuca rubra L. subsp. fallax [Thuill] Nyman) infected with the endophyte species Neotyphodium coenophialum and Epichloë festucae, respectively.
authors.affiliation: Department of Plant Biology and Pathology, Cook College, Rutgers University, 59 Dudley Road, New Brunswick, New Jersey 08903, USA.
authors.forename: Melinda
authors.initials: M
authors.lastname: Moy
authors.forename: Huaijun Michael
authors.initials: HM
authors.lastname: Li
authors.forename: Ray
authors.initials: R
authors.lastname: Sullivan
authors.forename: James F
authors.initials: JF
authors.lastname: White
authors.forename: Faith C
authors.initials: FC
authors.lastname: Belanger
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D004790:Enzyme Induction; D015971:Gene Expression Regulation, Enzymologic; D005936:Glucans / Q000378:metabolism; D006026:Glycoside Hydrolases / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D003904:Mitosporic Fungi / Q000201:enzymology / Q000235:genetics / Q000254:growth & development*; D008969:Molecular Sequence Data; D006109:Poaceae / Q000382:microbiology*; D012441:Saccharomyces cerevisiae / Q000235:genetics; D013379:Substrate Specificity; D047071:beta-Glucans
chemical_list: D005936:Glucans; D047071:beta-Glucans; C064197:beta-1,6-glucan; D006026:Glycoside Hydrolases; C020105:endo-1,6-beta-glucanase