The two genetic markers allow the detection and quantification of donor and transconjugant cells independently from the bacterial or ABR gene load in the background flora. This work was supported by ETH Zurich, project number TH-30.7 06-3. We thank Karen P. Scott (Rowett Research Institute) for providing E. faecalis CG110/gfp, and Roger Stephan (Institute for Food Safety and Hygiene, University of Zurich) for providing L. monocytogenes LM15. “
“A survey of the endophytic fungal community of wild rice (Oryza granulata) in China was conducted. Two isolates recovered from healthy roots are assumed to be dark septate endophytes (DSEs). They are morphologically Selleck 5-Fluoracil similar to species from the
genus Harpophora and are identified as a new species, Harpophora oryzae, based on the molecular phylogeny and morphological characteristics. A neighbor-joining tree constructed from ITS–5.8S rRNA gene regions reveals Alectinib solubility dmso that H. oryzae forms a distinctive subclade within the genus Harpophora, and is not genetically close to other species of Harpophora. Harpophora oryzae exhibits a moderate growth rate, with a frequent production of rope-like strands. It sporulates readily on artificial medium. Phialides are usually flask or bottle shaped and occur singly along hyphae or laterally and terminally on branched, hyaline to brown conidiophores, and also form whorls on metulae. Conidiophores are mostly branched with a slightly thickened wall, varying in dimensions.
Conidia are one-celled and hyaline, most of them being falcate and strongly curved. The morphological differences between Harpophora spp. and Harpophora-like anamorphs representing different orders are also discussed. An in vitro inoculation test showed that H. oryzae may contribute towards improving rice (Oryza sativa L.) growth.
Microscopic inspection of roots and phylogenetic placement of isolates further confirmed that H. oryzae represents a novel member of DSEs. Plant roots have been considered as a large reservoir of many types of mutualistic microorganisms (Sieber, 2002; Vandenkoornhuyse et al., 2007). Besides the well-documented nitrogen-fixing root nodule symbiosis and various mycorrhizal associations (Rengel, 2002; Parniske, 2008), fungal root endophytes may be widely distributed in nonleguminous or nonmycorrhizal plants and play an equally significant role (Vandenkoornhuyse Quinapyramine et al., 2002; Porras-Alfaro et al., 2008). Mycelium radicis atrovirens or dark septate endophytes (DSE) are a phylogenetically diverse group among root fungal endophytes (Sieber, 2002; Grünig et al., 2008). These fungi are generally characterized by melanized, septate hyphae and do not readily sporulate in artificial media. The Phialophora–Gaeumannomyces complex and Phialocephala fortinii constitute two major subgroups of DSEs (Sieber, 2002). Certain members of the genera Phialophora, now Harpophora spp., usually live in herbaceous plant roots as hosts, especially in Gramineae (Sieber, 2002).