title: Functional characterization of salicylate hydroxylase from the fungal endophyte Epichloë festucae.
abstract: Epichloë spp. are symbiotic fungal endophytes of many cool season grasses. The presence of the fungal endophytes often confers insect, drought, and disease tolerance to the host grasses. The presence of the fungal endophytes within the host plants does not elicit host defense responses. The molecular basis for this phenomenon is not known. Epichloë festucae, the endophyte of Festuca rubra, expresses a salicylate hydroxylase similar to NahG from the bacterium Pseudomonas putida. Few fungal salicylate hydroxylase enzymes have been reported. The in planta expression of an endophyte salicylate hydroxylase raised the possibility that degradation of plant-produced salicylic acid is a factor in the mechanism of how the endophyte avoids eliciting host plant defenses. Here we report the characterization of the E. festucae salicylate hydroxylase, designated Efe-shyA. Although the fungal enzyme has the expected activity, based on salicylic acid levels in endophyte-free and endophyte-infected plants it is unlikely that expression of the endophyte salicylate hydroxylase is a factor in the lack of a host defense response to the presence of the fungal endophyte.
authors.affiliation: Department of Plant Biology and Pathology, Rutgers University, New Brunswick, New Jersey 08901.
authors.forename: Karen V
authors.initials: KV
authors.lastname: Ambrose
authors.affiliation: Department of Plant Biology and Pathology, Rutgers University, New Brunswick, New Jersey 08901.
authors.forename: Zipeng
authors.initials: Z
authors.lastname: Tian
authors.affiliation: Department of Plant Biology and Pathology, Rutgers University, New Brunswick, New Jersey 08901.
authors.forename: Yifei
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Plant Biology and Pathology, Rutgers University, New Brunswick, New Jersey 08901.
authors.forename: Jordan
authors.initials: J
authors.lastname: Smith
authors.affiliation: Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, New Jersey 08901.
authors.forename: Gerben
authors.initials: G
authors.lastname: Zylstra
authors.affiliation: Department of Plant Biology and Pathology, Rutgers University, New Brunswick, New Jersey 08901.
authors.forename: Bingru
authors.initials: B
authors.lastname: Huang
authors.affiliation: Department of Plant Biology and Pathology, Rutgers University, New Brunswick, New Jersey 08901.
authors.forename: Faith C
authors.initials: FC
authors.lastname: Belanger
mesh_terms: D055864:Droughts; D060026:Endophytes / Q000378:metabolism*; D055329:Epichloe / Q000378:metabolism*; D006899:Mixed Function Oxygenases / Q000378:metabolism*; D006109:Poaceae / Q000378:metabolism / Q000382:microbiology; D013559:Symbiosis / Q000502:physiology
chemical_list: D006899:Mixed Function Oxygenases; C022619:salicylate 1-monooxygenase